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Comprehensive Five Day Training Program for Certified Energy Managers
Comprehensive Five Day Training Program For Certified Energy Managers March 1, 2013
©
Association of Energy Engineers 2013
As a courtesy to everyone attending this seminar, please: Turn off your cell phones. Set your pagers on vibrate.
Introduction • 2
Reminder for CEM Test • No wireless devices of any kind can be used on the CEM test. All cell phones and wireless devices must be put away, and cannot be used for any purpose - including use as your watch . • No computer use of any type is allowed. A computer cannot be used during the exam to access AEE CD's, software of any type, spreadsheets for either data or calculation purposes, or for any other purpose. • Hand calculator (non-wireless) use for problem solving is a required skill for any of the CEM preparation courses and for this course . Introduction - 3
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435 - Energy Efficiency Standards for New Federal Low-Rise ./ Residential Bui/dings - based on 30% better than ICC lEGe 2004 where Lee effectiV: _ 15
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State Building Codes Energy Component • In accordance with the Energy Conservation and Production Act (ECPA) as amended by EPAct 1992 and 2005, most states use the ASHRAE/IES 90.1 Standard as the basis for the energy component of their commercial building codes • Most states use the International Code Council (ICC) International Energy Conservation Code (IECC) as the basis for the energy component of their residential building energy codes • See www.energycodes.gov for latest determination status
0 · 16
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Status of Code Adoption: Commercial Overview of the currently adopted commercial energy code in each state as or JanlRlry 5. 201\
Source: www.energycodes.govF:="''''='''''':='''':i
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D - 17
Status of Code Adoption: Residential Overview of the currently adopted residential energy code in each state tiS of January 5, 20 11
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Building Energy Design Doing Better than Required • ASHRAE Standards are based on minimum standards that should routinely be life-cycle cost (LCC) effective; in most cases, buildings can be designed much better and still be LCC effective. • ASHRAE publishes Advanced Energy Design Guides (AEDG) to provide specific recommendations for achieving 30% energy savings over the minimum. • Use of the guides provides a prescriptive path to achieving LEED v2.2 Energy and Atmosphere credits for New Construction and Major Renovation projects. • AEDGs are available as free downloads at www .ashrae.orq 'TeChnOI~q;," and 'ilWWI}!jjWr:L.,£elOn~eIlrq;nY{s'Q~iet~itflr~~59 ·1
Recent Developments • The stated goal of the ASHRAEjIE5 55 PC 90.1 for the 2010 standard was to reduce energy cost by 30% compared to the 2004 version; initial estimates project 23.4 energy cost savings and 24.8% energy savings - expanded scope to include receptacle and process loads (e.g., data centers) and increased stringency of building envelope, lighting power densities lowered and most equipment efficiencies higher
• The 2012 IECC will include changes approved in Charlotte, NC in October 2010 that are projected to achieve 30% energy savings compared to the 2006 version • High-Performance Green Building Standards and Codes are emerging that include energy efficiency requirements, but with expanded requirements to include site sustainability, water use efficiency and in:o~or environmental qUalitl ~ Ef-I·~r.;t1
Green Energy Codes and Stan~ ~Y
~ ANSI/ ASHRAE/USGBC/IES Standard
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- 2009 "Standard for the Design of HighPerformance Green Buildings Except Low-Rise Residential Buildings"
p,..."s..;ljIY • Brokers (most) typically are _ C1 .? 'pJ~{ - Paid by marketer {" - Based on quantity of energy sold • Broker may - Promote long-term contracts to increase quantity ./ - Deal only with marketers who pay them best. 20
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Assess Risks
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Determine Risk To l erances
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Delineate Program Objectives
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Create Budget Setting Methodology
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Establish Procedures
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Design lnternal Controls
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Determine Qua ntifiable Hedge Strategy
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Draft Policy 8: Procedure Document
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Present Prog r am Senior Management Approval
Point of Use Costs
27
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Table E-l: Energy Conversion Units 1 kWh .................................. 3412 1 ftl natural gas .................... 1000 1 Ccf natural gas .... 100 ftl natural 1 Mcf natural gas .. 1000 ftl natural 1 therm natural gas .... ..... 100,000 1 barrel crude oil ........... 5,100,000 1 ton coal ........ ............ 25,000,000 1 gallon gasoline .... ...... .... 125,000 1 gallon #2 fuel oil ........... 140,000 1 gallon LP gas .................. 95,000
28
Btu Btu gas gas Btu Btu Btu Btu Btu Btu
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Table E-1: Energy Conversion Units (cont.) 1 HP .. ... . .... ........... ... ... ... 746 watts 1 cord of wood .. .. ........ 30,000,000 Btu 1 MBtu* .... .. ...... .. .. .. .. .. .. ...... . 1000 Btu 1 MMBtu* ............ .. .. .. ........ .. .... 106 Btu 1 therm .. .............. .. .... ............. .. 105 Btu 1 Quad ....... .... ..... .. .. .. .. .. .. .. .. .. 10 15 Btu 1 MW** ...... ...... .... .. .......... .. 106 Watts 1 Boiler HP .. ...... ... .... .. ... 33,475 Btu/hr Note: * In English units, M = 1,000 ** In SI units, M = 1,000,000 29
Point of Use Cost • "Point of use" (POU) cost depends on energy purchase price and efficiency of use • Energy sources can be compared using POU costs converted to some common basis (therm, million Btu, kWh, etc.). • Million Btu (MMBtu) is common basis unit.
POU =
30
Purchase price per common energy unit Efficiency of use
----'---:::-::c'-c----:------=.'---
Point of Use Cost Example The steam boiler for a facility can operate on natural gas or oil. Using natural gas at $0.95 per therm, the boiler is 75% efficient. Using oil at $2.50 per gallon and 140,000 Btu per gallon, the boiler is 78% efficient. Which fuel source provides the lowest operating cost?
31
Solution: Select 1 MMBtu as the common unit of steam output. POU
$0.95 1 therm 1,000,000 Btu 1 gas MMBtu therm 100,000 Btu MMBtu 0.75 = $12.67/MMBtu
$
POU _ $ _ _ $2.501 1 gal 11,000,000 Btui 1 011 MMBtu gal 1140,000 Btul MMBtu 10.78 = $22.90/MMBtu
Select Natural Gas 32
Sample CEM POU Examples to work for practice • For a large boiler, you have the choice of the following energy sources. Calculate the POU cost per million Btu for each. - Natural gas at $6.00 per MCF, Eff = 80% - #2 Fuel oil at $1.50/gallon, Eff = 78% - Electricity at $.075/kWh, Eff = 99% 33
Point of Use Costs -Answers• Gas - $7.50/MMBtu -Oil - $13.74/MMBtu - Electricity - $22.20/MMBtu
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IOH'I
Energy Accounting and Benchmarking
F- 1
Basic Energy Accounting • Basic energy accounting deals with the following ideas: • Recognizing different energy and fuel types - Electricity, gas, light oil, steam, chilled water • Understanding energy related units - kW, kWh, Btu, MMBtu, MCF, CCF, therm, HP • Performing conversions to different energy related units - For example,
1 kWh
= 3412 Btu
F -2
Table F-l: Energy Conversion Units 1 kWh ... .. ........... .... ... ........ .. 3412 Btu 1 ~ (CF or SCF) natural gas. 1000 Btu 1 CCF natural gas ... 100 ft3 natural gas 1 MCF natural gas .1000 ft3 natural gas 1 therm natural gas .......... 100,000 Btu 1 barrel crude oil ........... 5,100,000 Btu 1 ton coal ........ ........... 25,000,000 Btu 1 gallon gasoline .. ............ 125,000 Btu 1 gallon #2 fuel oil .... ....... 140,000 Btu 1 gallon LP gas .................. 95,000 Btu
F- 3
Table F-l: Energy Conversion Units (cont.) 1 HP ............ ....................... 746 Watts 1 cord of wood ............ 30,000,000 Btu 1 MBtu* ............................... 1000 Btu 1 MMBtu* ...................... .... ..... 106 Btu 1 MCF .. .. ............................... 1 MMBtu 1 therm ..................................... 105 Btu 1 Quad .... .... .. ........................ 1015 Btu 1 MW** .............................. 106 Watts 1 Boiler HP ................... 33,475 Btu/hr Note: * In English units, M = 1,000 ** In 51 units, M = 1,000,000 F-4
Typical Unit Conversion Problem How many Btu are in 1000 kWh?
Solution X Btu
=
=
1000 kWh 13412 Btu kWh 3,412,000 Btu
In this example, the two kWh units cancel out, leaving the remaining unit on the right side as Btu. F·5
Energy Use Index (EUI) • Basic measure of a facility's energy performance • A statement of the number of Btu of energy used annually per square foot of conditioned space • To compute the EUI - Identify all the forms of energy used in the facility - Tabulate the total energy in Btu used in the facility - Determine the total number of square feet of conditioned space F· 6
• The Energy Use Index is the ratio of the total Btu used per year to the total number of square feet of conditioned space. • A typical office building in the US has an EUI of about 92,900 Btu/square foot/year. • Food service facilities in the US have the highest average EUl's of over 258,000 Btu/square foot/year. • Inpatient health care facilities are just under 250,000 Btu/square foot/year.
F -7
Energy Use Index for Commercial Buildings 1000 Btu/sq ft/yr (2003 CBECS data)
.
300 250 200
150
-
100
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IDR
50
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/TrY;? EUI Computation Example • An office building has 100,000 square feet of conditioned floor space and uses 1.76 million kWh and 6,500,000 cubic feet of natural gas in one year.
• Convert the electric and gas use into Btu by finding the appropriate conversion factor in the table on pages F-3 and F-4.
F· 9
• One kWh electric energy is equal to ] • Thus, 1.76 million kWh is equal to
Lf I 'L
Btu.
00o~ f{/~~b~
• One CF of natural gas is 1000 Btu, so 6,500,000 CF of gas is equal to b r, bO MM.'b~
• The EUI is then by
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I\I\fV'Btu divided square feet, and is equal to I 00; Btu/square foot/year. F - 10
• This va lue of I ~ I'~~~~~"
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10.8378 11.2741 11.6896 ,--... 12.0853 12.4622
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2.7860 0.3589 _ _' 2.9253 0.3418 3.0715 0.3256 3.2251 _~ 1--0 .31 Q1 __ 0.2953 3.3864
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35.7193 38.5052 41.4305 44.5020 47.7271
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12.8212 0.0280 0.0260 _. ~ 13.1630 0.0241 . 13.4886 0.0225 .. 13.7986.._ 14.0939 0.0210
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LCC Time Value of Money Table ~
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0.9434 ___ 0.8900 0.8396 0.7921 0.7473
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6.9753 0.1434 8.3938 0.1191 9.8975 0.1010 'r 11.4913 0.0870 . 13.1808 0.0759
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39.9927 43.3923 46.9958 50.8156 54.8645
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Uniform Series To Find A To Find P To Find A GivenF Given A Given P ~(A7P~i%,nr~ (AlF,i"io,n) (P/A,i"io,nj
To Find F Given A (F/A,i"io,n)
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Sinqle Sums To Find F To Find P Given P I-~Qiven F,:~ (F/P,i"io,n) (P/F,i"io,n)
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10.1059 10.4773 10.8276 11.1581 11.4699
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0.0990 0.0954 0.0924 0.0896 0.0872
11.7641 .-------, 0.0850 12.0416 0.0830 12.3034 0.0813 12.5504 0.079?_ 12.7834 0.0782
LCCTime Value of Money Table Sinale Sums To Find F To Find P To Find F GivenP GivenF ~~GivenA~_ (F/P,i%-,n) (P/F,i%,n) (F/A,i%,n)
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Ughtlng l- 11
Color Temperature 0000 7500 71)00
6500
flOOO 5500
5000 4500 4000
asoo ;1000 2500 2000
1500 Correlated Color Temperature Chart Ughting L· 12
Types of Light Sources I Incandescent i
Tungsten Halogen t Mercury Vapor (old, rarely seen.any more) , Fluorescent - linear, U-tubes, CFLs Induction lamps Metal Halide (Poor color temperature stability) High Pressure Sodium (yellowish) Low Pressure Sodium (orange, mono-chromatic) Laser lights \ fLED - Light emitting diodes Natural (sunlight) Ughting l- 13
Efficacy Comparison of Lamps
~;:jo~$o:!sW#j
i
~~Zl'o$SW«I:I
-Ughting L - 14
Light Source Efficacy
Average Rated Life • Average rated life of a lamp is median value of life expectancy of a group of lamps - Time at which 50% have failed, 50% are surviving - Fluorescent lamps rated at 3 hours on, 20 minutes off per operating cycle - HID lamps rated at 10 hours on, one hour off per operating cycle • Increased frequency of switching will decrease lamp life in hours, but typically increase useful calendar life - Energy savings more significant than lamp costs
Ughting L - 16
Lighting Maintenance Principles • Light output of all lighting systems decreases over time • Lighting systems are over-designed to compensate for future light loss • Improving maintenance practices can reduce light loss (depreciation) and can either: - allow reductions in energy consumption (redesign), or - improve light levels • Group maintenance practices save money Ughting l- 17
Lamp Lumen Depreciation (LLD)
... _. _.....L ........ .- ............ !
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3
6
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.
18
21
24
@ESooree;(lahltom Nalkmal Ughting Bureau -~--.
Lighting System Design Methods 1.
Lumen Method • Assumes an equal footcandle level throughout the area. • This method has been used frequently since it is simple. 2. Point by Point Method • The current method of design based on the Fundamental Law of Illumination. • Requires a computer program and extensive computation.
Ughting l- 19
Lumen Method Formula
N= where
FlxA LuxLLFxCu
N = the number of lamps required Fl = the required foot-candle level at the task A = area of the room in square feet Lu = the lumen output per lamp Cu = the coefficient of utilization LLF = the combined light loss factor
Ughtlng L - 20
Example of Lumen Method Find the number of lamps required to provide a uniform 50 foot candles on the working surface in a 40 x 30 room. Assume two 3000 lumen lamps each per fixture, and assume that llF is 0.65 and CU is 70%.
N
=
50X1200 3000XO.65XO.7
= 44
The number of two-lamp fixtures needed is 22.
Ughting l- 21
The Coefficient of Utilization (CU) The coefficient of utilization is a measure of how well the light coming out of the lamps and the fixture contributes to the useful light level at the work surface. It may be given, or you may need to find it:
- Use Room Cavity Ratio (RCR) to incorporate room geometry - Use Photometric Chart for specific lamp and fixture Ughting L - 22
Room Cavity Ratio (RCR) RCR
= 2.5 x h x (Room Perimeter)/(Room Area)
Or, if the room is rectangular: RCR = 5 x h x (L+W)/(LxW) Where L = room length W = room width h = height from lamp to top of working surface
Ughting L - 23
Example Find the RCR for a 30 by 40 rectangular room with lamps mounted on the ceiling at a height of 9.5 feet, and the work surface is a standard 30 inch desk. h 9.5 - 2.5 7 feet
= =
RCR
= 5 x h x (L+W)/(LxW)
= 5 x 7 x (30 + 40)/(30 x 40)
= 35 x 70/1200 = 2.04
Ughting L - 24
Photometric Chart ... I\CPOl"t I~nmp:
l~~H
lUn 400 Watt (';ICtu'
Lurnen!! lO
80 75 70
70 50
•• 8. 75
6l"'_~~0._.l>_fIH
m
LED Lighting • Proven applications: - Exit Signs 95+% of all new exit lights are LED lights) - Traffic Signals 140 W to 13 W LED • Green 12" ball 140 W to 11 W LED • Red 12" ball
• Life
1 year to 7 years for LED • Cost $3 to $75 for LED - Commercial Advertising Signs (Neon) • Neon 15 mm tube 3 W/ft • LED 15 mm replacement 1.03 W/ft
Ughting L - 47
New LEOs for White Light • Growth Area ... but beware of lamp life and lumen depreciation.
• Watch for this technology to become more accepted as development is rapid.
Ughting L - 48
C\Cf(f
Parking Lot Example: "white" light appears brighter to eye!
Parking Lot Example: "white" light appears brighter to eye!
IIIIIIII Total System Wattage
300W
141 W
Average Delivered Lumens per fixture (photopic)
19,000
8,040
Average Footcandles (photopic)
1.96
1.01
Average Delivered Lumens (scotopic)
11,780
17,200
Average Footcandles (scotopic)
122
2.16
Photopic vision is how the eye perceives objects and colors under bright light. Conversely, scotopic vision is how the eye perceives objects and colors unde low-light condilions, such as a parking lot at night. The above measurements show that LED lights provide more perceived lightat night while using much less energy.
LED Examples: Before
LED Examples: After
• Street & Parking lot lighting
, Parking garages
, Atrium 'Julmels " ' Hazardous work areas
Sunlight • Natural lighting-often can supplement or replace lamps - Skylights • Best for new construction • With appropriate design, electric lamps can be off for much of the day • Major complaint is water leakage, not lighting issues - Tubular skylights • Useful for multistory applications Lighting l- 55
Tubular Skylight Examples*
*Beijing Eastview New Energy Technology Co., Ltd. Lighting l- 56
Lighting Control Technologies • • • • • • • • •
On/off snap switch Timers and control systems Solid-state dimmers Dimming electronic ballasts Occupancy sensors Daylighting level sensors Bank switching Full circuit dimmers for Demand Response Digital addressable lighting controls, DALI lighting l- 57
Typical Lighting Operation Building Type
Annual Hours of Operation
Education
3500 2605
ughting l- 58
Energy Savings Potential With Occupancy Sensors Energy Savings
Application Offices (Private) Offices (Open Spaces) Rest Rooms Corridors Storage Areas Meeting Rooms Conference Rooms Warehouses
25-50% 20-25% 30-75% 30-40% 45-65% 45-65% 45-65% 50-75%
lighting L - 59
CEM Exam Review Questions 1.
The efficacy of a light source refers to the color rendering index of the lamp. B) False A) True
2.
Increasing the coefficient of utilization of fixtures in a room will in many instances increase the number of lamps required. A) True B) False
3.
Which HID lamp has the highest efficacy - for the same wattage? A) Mercury vapor B) Metal halide C) High pressure sodium Ughting l- 60
4.
One disadvantage to metal halide lamps is a pronounced tendency to shift colors as the lamp ages. A) True B) False
(f)D r9f!>
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L-___________________
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~_. _··_-~· ~
____________
__ ·..
5. A 244,000 square foot high bay facility is presently lit with 800 twin 400 watt mercury vapor fixtures (455 watts per lamp including ballast). What are the annual savings of replacing the existing lighting system with 800 single 400-watt high-pressure sodium fixtures (465 watts per lamp including ballast)? Assume 8000 hours operation per year, an energy cost of $0.05 per kWh, and a demand cost of $6.00 per kW-month. Solution
Ughting L ~ 62
Solution AkW
= (800 fixtures)(A55 kW/lamp)(2 lamps/fixture)(800 fixtures)(A65 kW/fixture) = 356 kW
Demand $ savings $25,632fyr Energy $ savings
= (356 kW)($6/kW-mo)(12 mofyr) =
= (356 kW)(8000 hrsfyr) )($0.05/kWh) =$142,400fyr
Total $ savings = ($25,632 Cost
+ $142,400)fyr
= $168,032/yr
= (800 fixtures)($400/fixture) = $320,000 ?? Ughting L - 63
7. The Light Switch Problem (lust for Fun) You must determine which switch on a three sWitch panel on the first floor of a building controls a light on the fifth floor of the building. • The other two SWitches are not connected to anything and there is no way to see any light from the fifth floor without going up stairs. •
You have no tools and you cannot take the switch cover off.
•
You can only make one trip up the stairs to the light. How can you determine which switch operates the light?
Ughting L - 64
Solution Turn on the middle switch and the right-hand switch, wait 10 minutes. Turn the middle one off and run up the stairs. - If the light bulb is off and cold it is the lefthand switch. - If the bulb is off and hot it is middle switch. - If the bulb is on it is the right-hand switch.
Ughting L - 65
Electric Motors and Drives
Motors Ml
~
1
Electric Motor Management • • • • • •
Why bother? Electric motor basics Electricity and electric motors Energy efficient electric motors Electric motor inventories and rewind policies Motor drives -VFDs - Eddy current clutches - Permanent magnetic drives - Hydraulic drives, etc.
• Electricity basics review Motors Ml- 2
Electric Motor Management Why Bother? • Electric motors use "upwards of 60%" of all U.S. electricity and 45% globally* • Motor driven systems use over 70% electric energy for many plants • A heavily used motor can cost 10 times its first cost to run one year • On an average LCC basis, energy is about 95% of total cost of a motor 'US data from ACEEE, 2012; global data from Int1 Energy Agency, 2012 Motors Ml - 3
Motor Operating Cost Comparison -Motors, like automobiles, have performance ratings, depending on their size and configuration. -Motor performance is measured by efficiency. Automobile performance is measured by MPG. Automobile Purchase Price Annual Usage Efficiency Energy Cost Annual Operating Cost
$25,000 12,OOOmiles 20 mpg $2.50 Igallon $1,5001 year
Motors M1 -4
60 HP Motor $2,600 8,760 hours 93.6% 10¢ kWh
$41,8901 year
Electric Motor Management Why So Difficult? • Load on most driven systems is unknown at least on retrofits • Very difficult to determine load accurately through measurements • Electric motor management is FULL of surprises • Yet, savings can be large (small percentage of a big number is a big number) • Important note: Often oversized wiring (above code) is cost effective in heavily used systems as it reduces FR losses. (CDA and Southwire Corp.) MotorsMl-5 oi;
40
36
'~iV
35
30 ....
'"
15
10
800
1000
1200
'"
-*
-+
OM"•••,
Motors M1 - 57
Electric Motor Management Selection of Best Option • Outlet damper control . - Simple and effective - Not effiCient, infrequently used - Great candidate for conversion to others • Inlet vane control - Simple and effective - More efficient than outlet damper, but significantly less than other options, fairly frequently used - Great candidate for conversion to others Motors Ml 58 M
.
Electric Motor Management Selection of Best Option • Variable Frequency Drive (VFD) - Probably most efficient - Competitive cost Harmonic concerns (input and output) - Remote (clean area) installation - Multiple motors may be connected to one drive providing higher savings, but sizing is critical - Motors and load must be agreeable to VFDs
t-
Motors Ml . 59
Variable Frequency Drive Example • A large (50 HP) blower with inlet vane control drives a VAV system operating 6500 hours per year. Energy costs $0.04/kWh. What is the total savings per year for removing the inlet vane control and replacing it with a VFD? - Assume the performance data in slide 56 and the loading data in slide 61 applies - Construct an Excel spread sheet to do the caiculation:i
Motors Ml - 60
Electric Motor Management Selection of Best Option • Outlet damper control . - Simple and effective - Not efficient, infrequently used - Great candidate for conversion to others • Inlet vane control - Simple and effective - More efficient than outlet damper, but significantly less than other options, fairly frequently used - Great candidate for conversion to others Motors Ml - 58 .
,,
\
Electric Motor Management Selection of Best. Option • Variable Frequency Drive (VFD) - Probably most efficient - Competitive cost { - Harmonic concerns (input and output) - Remote (clean area) installation - Multiple motors may be connected to one drive providing higher savings, but sizing is critical - Motors and load must be agreeable to VFDs Motors Ml - 59
Variable Frequency Drive Example
,
\
• A large (50 HP) blower with inlet vane control drives a VAV system operating 6500 hours per year. Energy costs $0.04/kWh. What is the total savings per year for removing the inlet vane control and replacing it with a VFD? - Assume the performance data in slide 56 and the loading data in slide 61 applies - Construct an Excel spread sheet to do the calculations
Motors Ml - 60
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Variable Frequency Drive Example
Annual Savings for a Large Air Handler Motors Ml - 62
Variable Frequency Drive Example • Calculation for 50% load row in Spread Sheet: (50HP)(O.746kWjHP)(O.72-0.20)(O.23)(6500hrJyr)($O.04jkWH) ; $1159
Spread Sheet repeats this for all rows
Motors Ml - 63
•
-
Electric Motor Management Selection of Best Option • Magnetic clutches (permanent magnet or eddy current) - Bulky and heavy on motor shaft ~- No harmonics - Close to same savings as VFDs, but less
Motors Ml - 64
$$$$ • Choose the technology that your staff understands and likes to use • You probably don't want to mix technologies in a given facility • Most efficient is VFD followed closely by magnetic clutching followed (way back) by inlet vane and outlet damper controls Motors Ml - 65
$$$$ • Concentrate on centrifugal or axial applications: - Chilled water pumps, cooling water pumps, etc. - Blowers on cooling towers or VAV (variableair-volume) HVAC units - Axial fans on induced draft cooling towers - Use square law curves of savings for axial fans (probably very conservative) Motors M1 - 66
$$$$ • For cooling towers, work on air side as opposed to water side - Larger motors - Doesn't affect operation as much (freeze protection, biological control, etc.) - Multiple cell towers may be a good candidate for one drive on multiple motors Motors Ml - 67
-
Electric Motor Management Axial and Reciprocating • Centrifugal laws do not apply • More difficult to predict savings but axial works well (use squared curve to approximate all but recip?) • Certainly, improved soft start operation and perhaps control) • Obviously, savings if converting from constant volume to variable volume Motors Ml . 68
$$$$ Variable Speed Drive Applications • Any large centrifugal blower or pump that runs a lot! - Constant volume? Convert to variable volume - Variable volume with inlet or outlet control • Chilled water pumps, large campus • Cooling water pumps • VAVs using inlet vane • Forced draft (blower) cooling towers Motors Ml - 69
New Technology Options • For variable speed applications in small air handlers and small HVAC systems, there are several new technologies that may be more energy efficient than AC induction motors with VFDs. • SR motors - switched reluctance motors • VR motors - variable reluctance motors • PM motors - permanent magnet motors • Electronically commutated motors Motors Ml
~
70
Sustainable Green Buildings Introduction to Sustainability, ENERGY STAR® for Buildings, Green Globes, LEED Programs, And ASH RAE 189.1
Updated - July 2011
Sustainability Defined Design Ecology Project: Sustainability is a state or process that can be maintained indefinitely. The principles of sustainability integrate three closely intertwined elements - the environment, the economy, and the social system - into a system that can be maintained in a healthy state indefinitely.
Brundtland Commission of the UN: Development is sustainable "if it meets the needs of the present without compromising the ability of future generations to meet their
own needs."
ASH RAE defines Sustainability: "Providing for the needs of the present without detracting from the ability to fulfill the needs of the future."
N-2
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Sustainable Design - Green Buildings Are designed and constructed in accordance with practices that significantly reduce or eliminate the cradle to grave negative impacts of buildings on the environment and occupants in five broad areas: • Sustainable Site Planning • Safeguarding Water and Water Efficiency • Energy Efficiency and Renewable Energy • Conservation of Materials and Resources • Indoor Environmental Quality All relate back to the previous definition of Sustainability All of these are contained in the LEED Standard (Leadership in Energy and Environmental Design)
N·3
I~I
Benefits of Green Buildings • •
Environmental - reduced impacts on natural resource consumption Economic - improves the bottom line - savings through efficiency and productivity
• •
Health and Safety - enhanced occupant comforVhealth Community - minimize strain on local infrastructures and improve the quality of life
•
Reduced Operating Costs - primarily through energy savings - lower energy bills by 20% to 50%
•
Optimized Life - cycle economic performance vs. minimum first cost emphasis.
•
Increased Building Valuation - use the formula: asset value increases at ten times the reduction in annual operating cost per sq. It basis (CAF) Decreased vacancies - improves tenant retention & gives a marketing edge
• •
Reduced liabilitv - improves risk management, Le. no mold
N·4
-
Energy Efficiency is the First Step to being Green The Energy Manager determines how "green" a new or existing building will be, in terms of greenhouse gas impacts and fuel consumption, The Energy Manager needs to playa leadership role in the green building process, regardless of the system or methodology used, BOMA - Kingsley Quarterly: The Building Owners & Managers Association (BOMA) and Kingsley Associates devoted an entire publication to this concept showing that energy costs represent 30% of a typical building's annual budget, and is the single largest operating cost. Energy Information Administration: Commercial buildings account for 18% of the total U,S. energy consumption. N-5
ENERGY STAR@: The First Step to Sustainable Green Buildings The ENERGY STAR for Commercial Buildings Program
N-6
latrCrl
Portfolio Manager and EPA's Energy Performance Score
N-7
Benchmark Using Portfolio Manager • Free, online, benchmarking tool for existing buildings • Measures whole-building actual energy performance using easy to understand 1 to 100 score • Tracks energy intensity, cost, emissions ~ Normalizes for weather, operating hours, occupant density, and other characteristics ~ Provides low-cost "pre-audits" of building energy use
• Helps meet regulatory requirements • Provides ENERGY STAR label for buildings • Also used for LEED EB (existing buildings)
N-8
Importance of a Comparative Metric Is 60 MPG high or low for this automobile?
s 90 kBtu/SF/YR high or low for this building?
EPA's National Energy Performance Score Scale The score scale overlays a 1 to 100 scale over national data, giving relative meaning to energy use
N - 10
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How Scores are Calculated • Most based on the Commercial Building Energy Consumption Survey (CBECS) v'National survey conducted by the Department of Energy's Energy Information Administration v'Conducted every four years v'Gathers data on building characteristics and energy use from thousands of buildings across the U.S. • The building is not compared directly to other buildings entered into Portfolio Manager • Statistically representative models are used to compare your building against similar buildings from CBECS
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N - 11
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Building Types Eligible to Receive an ENERGY STAR Score
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Senior care Communities Retail stores
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Warehouses N -12
Wastewater Treatment Plants
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Buildings Can Benchmark
Even if a building is not eligible to receive a score ... • Benchmark the building against itself and look at trends in historical data • Compare the building to others in a portfolio to create an "internal benchmark" • Compare the building's energy use intensity (EUI) to the national average for that building type to set performance targets
I~I
N - 13
User-Friendly Data Inputs
Examples N - 14
Ways to Obtain the Score or EUI •
Single Building Manual Entry
./ Enter building and energy consumption information directly into Portfolio Manager •
Excel Data Upload
./ Upload data into Portfolio Manager using an Excel template (for multiple buildings) •
Automated Benchmarking Services
./ Use an ENERGY STAR Service and Product Provider to have the rating automatically integrated into your energy information and bill handling system for a portfolio N -15
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Tools and Resources to Improve Building Energy Performance
N-18
Identify and Establish Priorities Across Your Portfolio of Buildings
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opportunities are in lower quartiles, where there is the greatest for
N -19
Leverage ENERGY STAR Tools to Plan Upgrades • Building Upgrade Manual • Financial Evaluation Tools - Building Upgrade Value Calculation - Financial Value Calculator - Cash Flow Opportunity Calculator • Live and online trainings on best practices
ENERGY STAR~' Building Upgrade Manual
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'~"""keopl£ in residences and other bUildings~~ • Many different machines • Many possible configurations • Oesigns are generally unique - Present many opportunities for savings • Many older system designs are inefficient - Present significant retrofit savings HVAC-3
Simple Systems • Residential systems are direct expansion COX) "split systems" - Outdoor unit is compressor and condenser - Indoor unit is evaporator • Rooftop Units CB.TU) are OX -Compressor and evaporator in same unit· - Examples are large warehouse
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• OX-air is directly oooIed in evapo
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Simple Systems • Evaporating a liquid requires energyusually in the form of heat • Heat in the room air evaporates the refrigerant in the evaporator - Residential located in attic or closet - RTU on roof with condenser • Fan blows warm room air across evaporator - Heat taken from air -Cold air sent to space HVAC-S
Simple Systems • Evaporated refrigerant vapor goes to the condenser and it is compressed - To condense a vapor it must be cooled and give up energy • Fan blows outdoor air across condenser - Refrigerant is condensed to liquid - Heat goes into outdoor air
HVAC-6
Refrigerant Properties
• Condenser must be hotter than outdoor air • Evaporator must be cooler than indoor air HVAC·7
Refrigerants • Mostly artificial, engineered substances • Methane molecule, CH 4 =1 carbon (C) and 4 hydrogen (H) atoms -R-12=replace H atoms with 2 CI and 2 F atoms, CCI 2F2 (CFC class) -R-22=replace 3 H atoms with 1 CI and 2 F atoms, CHClF2 (HCFC class) • Chlorine CI depletes the ozone layer HVAC·g
Refrigerants • CFC's-not produced in the US since Jan 1, 1996; world-wide production now banned. • HCFC production is to end by 2030. • US production of equipment using R-22 ended Jan 1, 2010. (use R-410a) • See the Montreal Protocol and related parts of the US Clean Air Act
HVAC -9
. Refrigerants • The group of fluorocarbons apparently least harmful to the ozone layer are the HFC's-hydrofluorocarbons having no CI. -R-134a and 410a are HFC's • New refrigerants - Positive impact on ozone, but still GHG - Negative impact on energy efficiency, somewhat restored by new designs HVAC -10
Refrigerants • Ozone Depletion Potential (ODP): ratio of the impact on ozone of a chemical compared to the impact of a similar mass of R-ll. - R-ll (CFCl 3 ) ODP defined to be 1.0. -ODP of the HFC's is zero (no chlorine). •
[http://www.epa.gov/ozone/defns.html; date visited 11/29/07]
HVAC -11
Vapor Compression Cycle
EXPANSION VALVE COMPRESSOR
INSIDE AIR HVAC -12
Large Buildings and Facilities • More complex, with additional systems • Chillers - Large energy consumers -Combine evaporator, compressor and condenser into single unit - Usually electric motor drive • Gas-engine drive and dual-drive models available
Large Buildings and Facilities • Fan blows room air across chilled water (CHW) coil in air handling unit (AHU) -Air enters coil at 1V75 of and is cooled to
1V55°F. - Heat from air goes into CHW • CHW approaches coil at 1V42 OF and leaves at 1V54 OF -CHW returns to chiller's evaporator section where it is cooled HVAC -14
Large Buildings and Facilities
• Refrigerant moves heat Q from evaporator to condenser - Heat Q is removed in condenser - Heat Q goes into water in cooling tower loop (or into air in air-cooled chiller) • Water goes to cooling tower - Some is evaporated, taking the heat Q from the rest of the water - Heat Q winds up in atmosphere HVAC -15
Large Buildings and Facilities • Condenser - Air-cooled chillers use outdoor air to remove the heat from the refrigerant - Liquid-cooled chillers typically remove heat from the refrigerant with water from a coolingtower loop
-
HVAC-16
Lt)W Loot
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Diagram of a Typical Chiller 850 F
Condenser Waler
95 0 F
Condenser
Expansion Valva
High Pressure Side
Motor
Low Pressure·Side
Evaporator
Chlll&d Water
44'F
54'F HVAC -17
~
Large Buildings and Facilities
• Performance values (peak efficiency) - Large centrifugal water-cooled chillers ",0.45 kW/ton (EER"'27) - Large air-cooled chillers ",0.9 kW/ton (EER"'13) • Not directly comparable-water-cooled chillers require'more peripherals, but still more efficient than air-cooled HVAC -18
Large Buildings and Facilities • Added complexity -CHW loop with pumps - Possibly cooling tower loop with pumps • Reasons for complexity -Costs significantly less to move heat in water than in air - Cooling towers more efficient and economical than air cooling HVAC-19
Cooling Towers • Work by evaporating water into atmosphere • 1000+ Btu of heat go into the atmosphere for each pound of water evaporated
Typical Chiller System
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coolillg ooil HV~ E001m; adapt!!d from EPA
How it all fits together· • People and other sources add heat Q to air • Air goes to AHU - Heat Q goes into CHW increasing its temp -Air gets cooler • CHW goes to chiller -Heat Q goes into (evaporates) refrigerant - Water gets chilled again HVAC·22
Heating • Except for heat pumps, heating is simpler • Small systems - Direct-fired natural gas or oil furnaces - Electric resistance heat furnaces - Electric resistance baseboard heating • Larger systems - Steam or hot water boilers may supply heat via coils in the AHU's HVAC·23
Fans • Fans are everywhere in HVAC systems - Commercial fans and blowers use 140,000 million kWh/year in US (worth about $14 billion) Remember-a pound of air costs more to move than a pound of water (and the Heat capacity of air is % that of water} • Big savings from proper fan management -By varying speed (much more late~--=
1>--.
HVAC-24
Fan Efficiency Guidelines • Fan Efficiency Guidelines (FEG) are coming • Fan efficiency requirements scheduled to appear in model codes and standards in: -2013 ASHRAE 90.1 (Energy Standard for Bldgs ... ) -2014 ASHRAE/USGBC 189.1 (Design of High-Performance Green Bldgs ... ) -2015 International Energy HVAC·25
Fan Efficiency Guidelines • ASHRAE 90.1 will apply to most fans >5 hp • FEG reflects efficiency of fan only • European approach differs - Fan Motor Efficiency Guidelines (FMEG) address efficiency of fan-motor system • Effective Jan 1, 2013 for fans 125 W (1/6 hp) to 500 kW (670 hp)
Temperature Control Strategies • Vary supply air temperature while keeping air flow rate constant-CAV or constant air volume approach
y
i~u4 (r0
;J. Vary air flow rate while keeping the supply air ~~~ 'V temperature constant-VAV or variable air volum / system.
• Vary the supply air temperature and the flow rate as in a variable air volume reheat system. HVAC-27
Relative Humidity Control for Comfort • Humidification-Adding water vapor to air. • Dehumidification-Removing water vapor from air. - Accomplished typically by cooling the air below the dew point - Air may then be too cold for comfort - Reheat is used to reach comfort conditions • Either way, energy required is at least 1000 Btu per pound of water.
-
HVAC-28
-
Humidity Control • Rotary heat wheels can control humidity and temperature Rotatllm Of Wheel
Heat ond Moisture
E:r.chonVfr
Huted and Humidified Air
Worm Dry Eltboult Gos
Hot Humidified E"lIoll,t GOI
Duo:twork
*B.l. Capehart, et aI., G!Jidg to Energy Management 5th ed., Fairmont Press, 2003, p. 321. HVAC~29
Humidity Control (Graphic courtesey of HeatPipe Technology)
lt1\jtea.$et!·60n:~ri$iit$', HVAC-'.
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Air Delivery Systems • Single duct, single zone system • Zone is controlled by single thermostat • Single duct, terminal reheat system
.
• Multizone system (, 0 ~~ • Dual duct system ./ \lfJ 0~'
• Single duct, variable air volume system - Most common system installed in large commercial buildings • Fan coil system
HVAC-31
VAV HVAC Systems • High efficiency because of use of variable speed drive on the supply air fan. • Zone thermostat typically sends signal to local terminal box (VAV box) above ceiling. - Too cold, damper closes to restrict air flow (must maintain minimum flow for ventilation) - Pressure goes up in supply trunk to terminal box - Static pressure sensor signals fan controller to slow fan to bring pressure back in range. HVAC -32
Power and Energy in Air Conditioning • One ton of Ale = 12,000 Btulhr - A ton is a measure of Ale power, and is used when sizing systems, or when determining electrical demand. • One ton-hour of Ale = 12,000 Btu - A ton-hour is a measure of Ale energy, and is used when sizing storage tanks for thermal energy storage (TES) systems, or when determining electrical energy consumption. HVAC ·33
Performance Measures • Energy Efficiency Ratio (EER)-ratio of cooling output in Btu to the energy in Wh to operate system. EER
Btu of cooling output
=-----Wh of electric input Btu/hr of cooling output
/
W of electric input
• EER is typically measured at fixed indoor and outdoor conditions. HVAC-34
--7 \3
Performance Measures • Seasonal Energy Efficiency Ratio (SEER) -Accounts for typical variation in outdoor temperature. - Higher than EER; used for units up to 10 tons
HVAC -35
Performance Measures • Coefficient of Performance (COP)-a more technical term, sometimes used COP
Heat removed from cold space or delivered to hot space Energy required to operate system
• For cooling, COP and EER are related EER
cop=--=3.412~ HVAC-36
Some Magic Numbers for EER and COP EER= Btu/h of cooling output W of electric power input
~' COP = EER /3.412 Btu/Wh
kWin
ton
12 3.517 EER COP
(Z
HVAC-37
Heating Seasonal Performance Factor • Measures cold-season performance of electric heat pump • Ratio of heat output in Btu during heating season to Wh of energy input. • A typical electric heat pump may have an HSPF of 8.65, and an SEER of 11.6. COP = HSPF 3.412~: HVAC -38
"-
,~::
Examples 1. A 10 ton cooling roof top A/C unit has an EER of 12. What is its COP? ~ ;;;-\0 2. A 10 ton cooling roof top A/C unit has an EER of 12. What is its kW input load at full capacity? 3. A 10 ton cooling roof top A/C unit has an EER of 8.5. What is its COP? 4.
A 10 ton cooling roof top A/C unit has an EER of 8.5. What is its kW input load at full capacity? HVAC-39
Absorption Chillers • Produce large quantities of chilled water using little electricity. • Need large source of waste or low-cost heathot water or steam • No CFCs. Most use ammonia and water or lithium bromide and water. • Characterized by low efficiency. • Single stage-COPs about 0.6 - 0.8 • Two-stage-COPs about 1.0 - 1.2 HVAC -40
~·)'1
Gas-Engine Driven Chillers • • • • • •
Significant electric demand savings Good part-load performance Heat recovery from engine (CHP) likely needed to be cost-effective Most applications in areas with high demand rates and low or moderate gas rates Available from manufacturers Some manufacturers have dual-drive (gas and electric) available HVAC -41
HRU - DeSuperheater • Recover heat from the 1V200 OF hot refrigerant gas exiting the compressor. • Cold water (50-70 OF) can be heated to 140 to 160 OF. • Heat recovered is about 2500 Btu per hour per ton capacity of the AC unit or air cooled chiller. • Commercially available: HVAC suppliers, or for example, Doucette Industries in York, PA or Trevor-Martin in St. Petersburg, FL. HVAC -42
System Improvements • Separate 24/7 loads; use dedicated, independent systems .. • Install VSD's on chillers, fans and pumps • Use economizer cycle when possible - Cool with cooling towers where possible • Reduce HVAC load by improving envelope (Section R) • Upgrade controls (Section V) HVAC -43
System Improvements • Consider other equipment/technology (see appendix) -Chillers with magnetic bearings & VFD's - Two-stage evaporative cooling - Chilled beam systems ..:.. Variable refrigerant flow systems - De-superheaters HVAC-44
CEM Review Problems 1. In a vapor compression cycle air conditioner, the refrigerant is always in the vapor state. A) True B) False 2. A roof top air conditioner has an EER of 9.2. What is its COP? 3.
Reheat may still be needed in an HVAC system even if the outside temperature is very high. A) True B) False HVAC -45
CEM Review Problems
7.h _
~-
4. A roof top air conditioner has an EER of 13.5. What is its kWjton rating? 5.
How many kWh is used to provide 120 million tonhours of air conditioning with a system having a COP of 3.0? Use kWhjton-h = 3.517jCOP.
HVAC-46
Boilers and Steam Systems
Main Topics • Boilers . • Combustion -Applies to boilers and other fired systems (furnaces, kilns, heaters, incinerators, thermal oxidizers, etc) • Steam Systems -Steam generators (boilers) - Distribution systems • Energy Conservation Opportunities 2
Why Bother?* • Boilers used 8,100 trillion Btu in 2005 -43,000 industrial boilers -120,000 in commertial buildings - Consumed 40% of the energy used in those two sectors - Few are electric - Most produce steam, some produce hot water 'Numbers from Characterization of the u.s. Industrial/Commercial Boiler . Population, Environmental Analysis, Inc., Arlington, Virginia, 2005. 3
Basic Boiler Types
Firetube Boiler -focus of discussion -Common in commercial bldgs 4
, Watertube Boiler
5
US Boiler Size Rating System • Boilers are rated in terms of input heat rate in MMBtu/hr or boiler horsepower output. ~. 1 boiler hp=33,475 Btu/hr • A 77% efficient boiler consumes 13 MMBtu/hr of fuel. What is its hp?
6
US Boilers • Most are skid-mounted package boilers - Include connections for fuel, steam line, water supply, exhaust stack and electricity - Most are under 600 boiler horsepower • 70% ( tv 114,OOO boilers) are less than 10 MMBtu/hr heat input ( tv 225 bhp)
7
Boiler MACT • National Emission Standard for Hazardous Air Pollutants (NESHAP) for Industrial, Commercial, and Institutional Boilers and Process Heaters -Known as Boiler MACT for Maximum Achievable Control Technology) - Emission and "work practice" standards by EPA as required by Clean Air Act 8
Boiler MACT • Initially issued 2004 by EPA • "Final" rules issued March 2011 and immediately stayed by EPA • Amendments issued December 2011 • Conservationists, industry, and courts have been involved in controversy • Rules possibly effective soon with compliance required about 2016? 9
Boiler MACT • An array of fuel types, boiler and process heater sizes, emission standards and rules has been on the table. - Planning (by industry, commerce, and institutions) has been based on rules in flux - Planning must continue-some organizations will spend millions and have trouble meeting the deadline 10
Boiler MACT • Larger (> 10 MMBtu) units burning coal or biomass likely will see greatest change -Controlled pollutants: HCI, Hg, PM or TSM (total s.elective metal) and CO? -Annual testing and tune up, monitoring, record keeping and reporting? - Facility energy assessment? - Sometimes expensive control equipment 11
Boiler MACT • Generally, smaller «10 MMBtu/hr?) units burning natural gas or refinery gas will see least effect - Tune up at least every 2 years or 5 years? - Facility energy assessment? Boiler MACT information derived from Burns and McDonnell white paper, An Overview of the EPA IndustrialBoiler MACT Rule, 12/2011, by Don Wolf, PE, and National Emission Standards for Hazardous Air Pollutants for Major Sources: Industrial, Commerdal, and Institutional Boilers and Process Heaters; Final Rule (40 CFR Part 63) 3/21/2011, US EPA
s
12
Boiler Controls • Modern modulating systems control firing rate based on load. -Air/fuel ratio is set by mechanical linkage -Best systems set air and fuel flow. independently based on measurements of O2 in stack. • Older, simpler systems were on/off, or high-fire/low-fire based on load. 13
Boiler Efficiency • Combustion efficiency-Ratio of fuel energy input to that expended in boiler. - Most energy goes to steam -Some is lost from boiler walls • Fuel-to-steam efficiency (FTSE)-Ratio of fuel energy input to energy in steam. - Usually a few percent lower than combustion efficiency - Relatively constant with load 14
Boiler FTSE Efficiency vs. Load • Boiler size in hp, pressures in psig. r'4A1lJRAl GAS IBOU.ER SI2E
Table from Boiler Efficiency Guide, Cleaver Brooks, Thomasville, Georgia, 2010 15
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Boiler Fuels • Most boilers burn natural gas • Natural gas after processing is about 96% methane gas, CH 4, (simplest hydrocarbon) • Know price point (point of use cost) for switching if that is an alternative
17
Boiler Fuels • Other boiler fuels -#2 fuel oil (similar to diesel) - #6 fuel oil (thick, viscous liquid, may require heat to move in winter) -Coal -By-product gas (e.g., refinery gas) -Waste fuel (e.g., wood waste, rice hulls, msw) 18
Combustion Efficiency • In any closed combustion system such as a boiler or a furnace without secondary air, combustion efficiency is determined by exhaust gas measurements • The goal is to be able to carefully control the fuel and airflow to ensure complete and efficient combustion. • Excess air is important and too much excess air is expensive.
CH4
+ 202 ~ CO2 + 2H 2 0 + _02 + _02 + _N2 + _ N2 19
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Measuring Efficiency • Typically by electronic instrument with probe in stack measuring: -02 level - Stack temperature rise (STR) above boiler room temperature • Other possible measurements -CO, NOx, 5° 2, unburned fuel 20
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Natural Gas Flue Gas Analysis vs. % Combustion Air 24
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51
Superheated Steam Example Consider installing a turbine to reduce the T and P of superheated steam from 1200°F and 200 psia to 700°F and 180 psia, and generate some electrical energy. a)How much energy are you capturing from each pound of steam by changing the enthalpy? b)The boiler runs 24 hrs/day, 7 days/wk, for 50 weeks/yr and sends 3,000 Ib/hr to the turbine. How much money are you saving if the cost of electricity $0.10/kWh? Assume that the generator is 100% efficient. 52
Solution 1200'
a) dh
= h200
700' -
h180
= 1635.4 Btu/lb -
1375.3 Btu/lb
= 260.1 Btu/lb b) $ savings:
= =
260.1 Btu Ib
x
6,555 x10' Btu yr
3,0001b hr
x
24hr
x
day
1 kWh 3,412 Btu
= $192,100/yr 53
x x
7 day week
x $0.10 kWh
50 week yr
Steam Traps • Condensing steam gives up its energy at constant temperature and the liquid condensate must be removed. • Three purposes of steam traps 1. Remove liquid condensate 2. Remove non-condensible gases such as air 3. Hold back live steam 54
Inverted Bucket Steam Trap
-~"1 olfl"v-15~ LV IV.
/""'" ,J;:
_!",'{ LiM - ~ /jJI}1 e,~
fJI,J
NOlmCJ1st~·:&ap
Opwatkm (lnvt!tri~dBf..leket)
55
pvoW5
Steam Traps • Prone to failure, they are a major source of steam leaks • Routine trap diagnostic and maintenance program is highly valuable • Call vendor or manufacturer for orifice size needed for leak rate • Other types include float, thermostatic, and venturi traps • Normally not insulated 56
Boiler Blowdown • Water, not steam, is removed • Top or surface blowdown -
Removes impurities Controls concentration ofTDS (Total Dissolved Solids) Usually continuous and low flowrate POSSible source of heat for makeup water or flash steam
• Bottom or mud blowdown - Removes sediment settled on bottom of boiler - Usually intermittent and brief with high flowrate
57
Boiler Blowdown Steam.;o S(tIlds
Top
. .... .....
Contllluo'UlI'
DloW(io>wn
Mud
- .- . -
BlowdowD. Sbdl&Tube lie,,,,, Ex(!l::ianger .Prell","l ~~ter
Make Up W:akr, Some.Sollds
58
Top Blowdown Heat Recovery Unit*
*Fig 1-16, Boiler Room Guide, Cleaver Brooks, Thomasville, Georgia, 2011 59
Flash Steam Recovery • Flash steam occurs by lowering the pressure on hot, liquid condensate • The liquid water hastoo much energy (is too hot) and loses energy to the appropriate temp by evaporation. • Resulting flash steam may be used for - Deaerators - Process needs 60
Flash Steam Recovery Vessel r--~SatLraled Vapor Supply
LIlW-Pressura Hlgh-Pr8Ssur~
COOIJertSaie
Flash Vessel
----{,I,.......---i stmTIifl
saturated Vapor
L..,
COntroller SatUJatad l.kJ!id Condensate
DIScharge '---~-r-
'---_-.l.'"'l..._ _ -
61
j
Flash Steam Recovery • Removing heat from the blowdown may be necessary to meet sewer requirements • After flashing the steam, the remaining liquid can be cooled by heating make-up water • The amount of steam produced is given by · Flash ed = H f (high pressure) - H f (low pressure) Frae t IOn Hfg(low pressure) 62
Flash Steam Example • 1000 Lb/h of blowdown at 120 psia is sent to a pressurized tank at 50 psia. How much low pressure steam is produced? · Flashed = H f (120psia) - H f (50psia) Fraet IOn
H fg (50 psia)
% Flashed = 312.6-250.2 =0.068 or 6.8% 923.9 • Mass lost
= (0.068)(1000 Lb/h) = 68 Lb/h 63
Condensate Disposition • Reusing condensate saves 1. Energy 2. Water 3. Water treatment 4. Sewer charges
64
Condensate Recovery • Atmospheric pressure recovery - Most common system - Limited to 212 of - Less expensive than pressurized system • High pressure recovery - Requires pressurized system - Recovers hotter water with more Btu's
I ~
65
When is Condensate Recovery Not Cost Effective? • Recovery is over considerable distance in an existing system • Condensate is contaminated
66
Boiler and Steam Plant ECO's INCREASE BOILER EFFICIENCY 1. Reduce Excess Air to Boiler(s) 2. Provide Sufficient Air to Boiler(s) for Complete Combustion 3. Install Low Excess Air Burner (s) 4. Repair/Replace Faulty Burner (s) 5. Repair Natural Draft Burner(s) with Forced Draft Burner(s) 6. Install Turbulators in Firetube Boiler(s) . 7. Replace Existing Boiler(s) with New More Efficient Boiler(s) 8. Install a Condensing BoilerlWater Heater 9. Install a Pulse Combustion BoilerlWater Heater 10. Install a Small Boiler for Summer Operation 11. Clean Boiler(s) to Eliminate Fouling and Scale 12. Improve Feedwater Chemical Treatment to Reduce Scaling 13. Optimize Boiler Loading When Using Multiple Boilers 67
Boiler and Steam Plant ECO's INSULATION 14. Install Insulation on Steam Line(s) 15. Install Insulation Jacket(s) on Steam Fitting(s) 16. Install Insulation on Feedwater Line(s) 17. Install Insulation on Condensate Return Line(s) 18. Install Insulation on Condensate/Feedwater/Deaerator Tank(s) 19. Install Insulation on (Domestic) Hot Water Line(s) 20. Install Insulation on (Domestic) Hot Water Tank 21. Install Insulation Jacket on Boiler Shell 22. Install Insulation to Reduce Heat Loss
68
Boiler and Steam Plant ECO's REDUCE BOILER LOAD 23. Repair Steam Leak(s) 24. Repair Failed Steam Trap(s) 25. Reduce Boiler Blowdown 26. Return Condensate to Boiler(s) 27. Shut Off Steam Tracer(s) During Summer 28. Shut Off or Turn Back Boiler During Long Periods of No Use 29. Change Boiler Steam Pressure 30. Replace Continuous Gas Pilot(s) with Electronic Pilot(s) 31. Install Stack Damper(s) to Reduce Natural Draft Heat Loss 32. Pressurize Condensate Return System 33. Reduce or Utilize Flash Steam 34. Reduce Boiler Load and/or Steam Requirement 69
t.:vrcr
Boiler and Steam Plant ECO's WASTE HEAT RECOVERY 35 .. Install an Economizer to Preheat Boiler Feedwater 36. Install Heat Exchanger to Preheat Boiler Makeup or Feedwater 37. Install Heat Exchanger to Recover Blowdown Heat 38. Install Recuperator to Preheat Combustion Air 39. Recover Waste Heat to Supplement (Domestic) Hot Water Demand 40. Recover Heat from Boiler Flue Gas to Supplement Bldg Heat 41. Install Heat Recovery Steam Generator on Incinerator 42. Direct Contact Condensation Heat Recovery
70
Boiler and Steam Plant ECO's OTHER 43. Vary (Domestic or Heating) Hot Water Temp. Based on Demand 44. Eliminate Air Conditioning in Boiler Room 45. Install Back Pressure Steam Turbine for Cogeneration 46. Switch to a "Self-Help" Natural Gas Source 47. Request Change to a Different Utility Rate Schedule 48. Switch to a More Economical Fuel Source 49. Install Heat Pump to Supplement (Domestic) Hot Water Demand 50. Replace Electric Boiler(s) with Natural Gas Fired Boiler(s) 51. Install a Satellite Boiler 52. Install a Variable Frequency Drive on Pump(s) and Fan(s) 53. Replace On/Off Control System with Variable Firing Rate
71
Compressed Air Systems and Pump Systems
Why Bother? • Industry uses most compressed air (CA) - Larger compressors - More end uses - More complex systems -Savings potential up to 30% often quoted • Commercial/Institutional buildings - Smaller compressors for pneumatic controls 2
Typical Commercial Building System • Reciprocating compressor
• • • •
• -
U)
D.~ C n:s
o.e
ClJu
c
o
N ~
.e
E o
U
J
Practice Problems • These are additional Building Envelope practice problems for you from the Sample CEM Test in Section J. We will most likely not have time to work them while covering the 0 section. These are for you to practice on. • Solutions are given at the end of the J Section. 43
CEMReview Problems An absorption chiller with a COP of 0.8 is powered by hot water that enters at 200°F and exits at 180°F at 25 gpm. The chilled water operates on a lQ°F temperature difference. Calculate the chilled water flow rate. (Solution does not require knowledge of how absorption chillers work internally). (A) 10gpm (6) 20 gpm (C) 40 gpm (D) 45 gpm (E) 30 gpm
See answer to question 10, Section J 44
Review Questions • Most of our homes and apartments are
a) thermally heavy b) thermally light
45
CEMReview Problems The conduction part of the Building Load Coefficient (UA) for a building is 5000 Btu/hr per degree F. Estimate the seasonal energy consumption for heating if the heating season has 3,500 degree days. The heating unit efficiency is 80%. Find the answer in MCF/yr. A.625 MCF/yr B.350 MCF/yr C.420 MCF/yr 0.656 MCFfyr E.525 MCFfyr
See answer to question 14, Section J 46
Electric Motor Management Selection of Best Option • Outlet damper control . - Simple and effective - Not efficient, infrequently used - Great candidate for conversion to others • Inlet vane control - Simple and effective - More efficient than outlet damper, but significantly less than other options, fairly frequently used - Great candidate for conversion to others Motors Ml - 58
Electric Motor Management Selection of Best Option • Variable Frequency Drive (VFD) - Probably most efficient - Competitive cost Harmonic concerns (input and output) - Remote (clean area) installation - Multiple motors may be connected to one drive providing higher savings, but sizing is critical - Motors and load must be agreeable to VFDs
..:f-
Motors Ml - 59
Variable Frequency Drive Example • A large (50 HP) blower with inlet vane control drives a VAV system operating 6500 hours per year. Energy costs $0.04/kWh. What is the total savings per year for removing the inlet vane control and replacing it with a VFD? - Assume the performance data in slide 56 and the loading data in slide 61 applies - Construct an Excel spread sheet to do the calculations
Motors Ml ~ 60
Thermal Energy Storage (Primarily for air conditioning)
s: Thermal Energy Storage-l
I~I
Why is There Interest in Thermal Energy Storage? • Reduced peak demand costs • Some utilities offer rebates and rate incentives • Reduced equipment size and cost (new) • May be improved reliability due to production and storage • Smaller fans and pumps (colder water with ice storage) 5: Thermal Energy storage-2
I~I
Economic Payback Time • Typical simple payback of 5 to 7 years (maybe 3 to 5 in some cases) for existing buildings and chillers . • Recent examples from ASHRAE and others are showing the payback may be immediate to 1 - 2 years for good design in new construction.
$: Thermal Energy Storage~3
Conventional Air Conditioning Operation • CAe system peaks at peak cooling time • CAe system is sized to meet peak cooling load
• CAe system may have its lowest efficiency at the time it is needed the most
5: Thermal Energy storage-4
I~I
CAC Operation Building Cooling Load Profile
1000
'W
750
~
~ 500 250
o ~'4~~~~~~~~~~'4~~0~~~~~~
0;;''''
~
",0
Time of Day 5: Thermal Energy Storage-5
Off-Peak Air Conditioning Operation • CAC together with storage is used to meet peak cooling loads • Chilled water or ice is used for storage medium • Daytime peak load is reduced or eliminated • OPAC system operates at night when efficiencies are usually higher due to lower outside temperatures
5: Thermal Energy Storage-6
Off-Peak Air Conditioning Operation • The Total Daily Cooling Load (plus system losses) must be met • The Instantaneous Cooling Loads must also be met when they occur, just not directly from the chillers. • We are simply decoupling the Load (demand) from the Chiller (supply) • If we take advantage of optimal chiller loading (sweet spot) and cooler condenser temperatures, we may gain significant efficiencies. 5: Thermal Energy Storage-7
I~I
Building Cooling Load Profile
I_ Building Load I
1000
.,c
~
750
~ .., ...8
500
LLoad X hours = 14,000 Ton-Hours
250
a .~'~~~~~~~~~~~,~~~~~~~~~~
.o~($
~
.;;;.0
Time of Day 5: Thermal Energy storage-8
OPAC Operating Strategies • Load leveling
- Partial shifting of AC load to off-peak hours - Chiller runs at constant load or near constant load for 24 hours per day - Very cost effective for new construction - Less costly to purchase - Less space needed - But'" less savings 5: Thermal Energy Storage-9
Load Leveling Chiller Load Calculations
• Where would we need to operate the chiller{s) in order to satisfy the building load? Peak period between 12:00 p.m. to 8 p.m. • Total Ton Hours / Hours available to operate chillers • For the Load Leveling Strategy, the chiller will operate 24 hours per day, at a load of:
-14,000 Ton-hours / 24 hours = 583.3 --' Tons 5: Thermal Energy Storage-tO
1C\ftfr1
Building Cooling Load Profile Load Levelling TES
1_ Building Load __ Load Levelling TES 1 1000 ~ II)
Peak: Chiller Load = 583.3 Tons
750
c
g 16 .3
500 250
o
5: Thermal Energy Storage-!1
10Cffr1
• Load shifting - Complete shifting of peak hour AC load to off-peak hours - OPAC system must be sized to meet peak cooling load in ton-h - Usually more cost effective for retrofit situations because of large existing chiller load that can be moved mostly off peak -More costly to purchase and install - Requires more space for storage tanks - But'" more savings 5: Thermal Energy storage-12
OPAC Load Calculations • Total Ton Hours / Hours available to operate chillers • A peak period from noon to 8 p.m. would only leave 16 hours to generate cooling capacity. • For the Load Shifting Strategy, the chiller Will. operate at a load of:
-14,000 Ton-hours / 16 hours = 875-, Tons ,/
IClCtfrII
5: Thermal Energy Storage-13
Building Cooling Load Profile
1_
Building Load _ _ Load Shifting rES
1000
.,
750
c
o
e
~ 500 ..J
250
o
S: Thermal Energy Storage-14
1
TES Storage Media • Chilled water storage - Simple but large tanks needed; lots of space. Requires 4 to 5 times the space of ice storage - Typical water temperatures of 39 to 40 deg F ~ - Practical considerations for water storage tanks N
• Need to minimize mixing of warm return / water with the cold water in storage • May need two tanks '" if full capacity of a tank is needed. If temperature stratification of tank is used, the tank may need to be up to 20% bigger
I~I
5: Thermal Energy Storage-1S
Stratified Water Tank
,!J-
..., c'-
./
,
~F
IChiller
155 F
I
140F
I
In Charge mode, the Chiller will generate cooling, and the valve and pump controls will supply building cooling with excess going to the tanle 5: Thermal Energy Storage-16
~
Stratified Water Tank ,-~~
---
~ ,7
~
?
'-
140F
I
IChiller ~ In Discharge mode, the tank will supplement the chiller ("load leveling" strategy) or Supply all the cooling required by !be building as in the "full shift" strategy. S: Thermal Energy Storage-17
I~II
%IvuJ~t&c
j; )~&-.I: .
• Ice Storage - More complex tanks and auxiliary equipment needed; more complex to maintain ~ Ice/water requires around 20 to 30% of 7' the space needed for chilled water tanks - Solid ice requires around 10% of the space needed for chilled water tanks - Very low temperature water can be used tv around 34 degrees F ~ J""..l i'-111~ - Can use ice harvester, ice on coil, or ice/water (slush) s: Thermal Energy Storage-1S
I
~ }'If hftc
I
....'-
./
CHWS
40 0 P
In Charge mode, the Ice Generator will circulate 28°p Water/Glycol mixture through Chilled Water Tank, freezing Chilled water on the coils. Warm CHWR melts the ice during Discharge, thus cooling the CHWS. 5: Thermal Energy storage-19
Properties of Storage Media • Chilled water systems are typically operated in a manner to use only sensible heat storage and thus stores one Btu per pound of water for each OF of temperature difference between the stored water and the returned water Ice systems are typically operated in a manner to use only latent heat associated with freezing and melting, and one pound of ice at 32°F absorbs 144 Btu to become 320 F water 5: Thermal Energy Storage-20
1Qff.f1
·s...~
Sizing Chilled Water Storage Tanks /If'
/n~
Assume that chilled water is stored at 400F and is returned at the standard temperature of 55°F • This is a 150 .'lT for the AC system. • Thus, one pound of water stores 15 Btu. • One ton-h of AC is 12,000 Btu So, to store 1 ton-h you need: . . b pounds of water; or, txx(;;::::-_1D.~;/\~ gallons of water; or, f;60(t- f f -cubicfeet of water. f/60/hl:;" /'Z'ff
It
5: Thermal Energy Storage-21
r
r. _
1C\!f!r....--.· ... -·... ~I
Can We Meet This Load With an OPAC System? • What is the current chiller configuration? • Assume two 600 ton chillers
• Can we store enough ton-h during off-peak hours to meet the daytime AC load without having to run the chiller at all during the day?
5: Thermal Energy Storage-22
I~I
~
How Big Would a Chilled Water Tank be to do Load Shifting? • Assuming we used the 15 degree delta T chilled water system, how many gallons of water would we need to store to meet the entire on-peak load shown on 5-14, assuming no losses?
, 7DDD
Jp.",-_'h. 1-
i{. (~ 01 >; [)')
0
5: Thermal Energy Storage-23
Efficiency and Capacity Considerations in Real Life • OPAC system is less efficient at lower water temperatures rv but night time operation is more efficient rv these might cancel each other • We mi~ht suffer a 10 to 15% capacity reduction because the OPAC system nas less capacity at lower water temperatures • We might lose 5 to 10% of capacity because of storage losses 5: Thermal Energy Storage-24
*"
Conditions That Favor TES
• High peak demand charges • Low cost of energy used at night • High on-peak loads • Low AC loads at night • Need for increased cooling system capacity
5: Thermal Energy Storage·25
TES Chilled Water Tank DFW
5: Thermal Energy Storage-29
TES Tank at DFW AlP
5: Thennal Energy Storage-30
DFWTES Data •
The DFW Airport TES tank: •
Tank fabricated and installed by CBr
•
Physical dimensions: 56 ft. in height with a diameter of 138 ft.
•
Storage volume: 6,000,000 gallons
•
Storage capacity: 90,000 ton-hours
•
Shifts over 15 MW off-peak
•
Simple payback on the incremental investment was 4 years
One other interesting fact the DFW CHW system was originally designed for a 24 degree Fdelta T with a leaving CHW temperature of 36 degrees F. The buoyancy of water inverts at 38 degrees F so 36 degree entering water would compromise the stratification in the TES. So, a buoyancy depressant called So Cool is used to depress the minimum buoyancy below 36 F. It has worked perfectly. s: Thermal Energy
Storage~31
TES for Heating • TES has many applications for heating • We already use it with our typical storage water heaters in our homes, offices and factories • Some space heating systems use ceramic bricks, rocks, water tanks, and phase change materials • Also many other applications in manufacturing and industry s: Thermal Energy Storage-32
CEM Review Problems
_S6;Je.i
1. TES systems yield large energy savings. A /' A) True (B)'False \ ...../ 2. TES for heating uses some of the following storages: 1) building mass; 2) hot water; 3) ground couple; 4) compressed air tanks; 5) rocks; and 6) propane containers. Select the right combination:
(A) 1,2,3,4 ~ 1,2,3,5
I'
(B) 3,4,5,6 (D) 2,4,5,6
S: Thermal Energy Storage-33
I~I
3. With a load leveling TES strategy, a building manager will ) Not operate the chiller during peak hours (B Essentially base load the chiller (i.e., ....... operate at high load most of the time) (C)Operate only during the peak times (D)Operate in the "off" season
~
4. A large commercial building will be retrofitted with a closed loop water to air heat pump . system. Departments are individually metered. Demand billing is a small part of the total electrical cost. Would you recommend a TES? . rD\' B.\No (A) Yes
~:~;rmal Energy Storage-34
I~I
5. Water can store heating capacity or coaling capacity in sensible or latent heat since it has useful phase change p,bysical characteristics. (A)lTrue (8) False ,J
5: Thermal Energy Storage-35
Combined Heat and Power, and Renewable Energy Section T
T-CHP and Renewable Energy
Overlapping Definitions • Distributed generation (DG) - Electricity production at or near the point of use, irrespective of size, technology or fuel used, both off-grid and on-grid • Combined heat and power (CHP) - Produces both useful mechanical energy and useful thermal energy from a single system. - Mechanical energy can generate electricity or be used directly as shaft energy. T·CHP and Renewable Energy
Overlapping Definitions • Renewable energy - Renewable energy is energy from natural resources, which are naturally replenished in the short term - Can be a form of DG -Can be a central plant -Can generate thermal and/or electrical
T-CHP and Renewable Energy
Why Consider This? (Advantages) • • • • • •
Increase efficiency Improve reliability Reduce emissions Improve energy security Reduce long-term costs Hedging against future energy costs
T-CHP and Renewable Energy
~
5
Major Barriers • • • • • • • • • •
Application procedures Exit fees Feed-tariffs and metering Financing Load retention rates Interconnection Insurance Siting and permitting (regulations and land area) Skilled labor (design, maintenance, operation) Back up and standby fees T-CHP and Renewable Energy
Combined Heat and Power (CHP) • Also known as: - Cogeneration - Combined cooling, heating and power (CCHP) - Building cooling,· heating and power (BCHP) - Trigeneration (power, heating, and cooling) T-CHP and Renewable Energy
Combined Heat and Power • Definition: Simultaneous production and use of useful mechanical energy and useful thermal energy - Mechanical energy can be used directly (e.g., power an air compressor) • Most often generates electricity - Thermal energy can be used directly, or can generate cooling (e.g., heat source for absorption chiller) T-CHP and Renewable Energy
WhyCHP? • CHP has the opportunity to: - Improve system efficiency (compared to typical power generation without useful heat recovery) - Reduce total operating costs (compared to purchasing or generating electricity and heat energy in separate systems) - Improve system reliability and availability (when CHP is used as primary and the utility systems are used as a back-up source) - Can reduce total emissions (although may increase local emissions) 9
T-CHP and Renewable Energy
CHP Energy Balance Combined Heat & Power
Conventional Generation
5 MWN;"JIIJIM GJ\ii CUmbu$U11ft -Ttlrtlb"~
Heal
,A·gOF OVERALl: "+ /0 EFFICIENCY
Hoot
.
'71::01
Source: EPA Combined Heat and Power Partnership (www.epa.gov/chp)
T·CHP and Renewable Energy
OVERALL
,1'i.1 10 EFFICIENCY
~
10
CHP Emissions Reduction Increased Efficiency Results in Reduced Carbon Emissions
TRADITIONAl SYSTEM
CHPSYSTEM
i:xampm ill tllo GO? S'·,availablein •.....
43 states + D.C.
~
54
Renewable Energy Certificates • Also known as RECs, green certificates, green tags, or tradable renewable certificates. • Represent the environmental attributes of the power produced from renewable energy projects and are sold separate from commodity electricity . • Customers can buy RECs whether or not they have access to green power through their local utility and do not have to switch electric suppliers. Cost can range from O.S¢ to 6¢/kWh, depending on type and location. T-CHP and Renewable Energy
cxtcf
55
Green Power • Green power/green energy typically refers to: - On-site renewable energy generation - Buying green energy which the utility generated from renewable energy sources - Buying renewable energy certificates CREes) • Not limited to electricity. Landfill gas, biomass, bio-diesel and others may be considered green energy. T-CHP and Renewable Energy
C'MPCr
56
Net Zero Energy • Several organizations have the goal of developing net zero energy buildings • Net zero energy buildings are highly efficient but still consume energy • Energy needs are met through self generation and interconnection to the utility grid and utilize net metering • "Net" zero is typically defined on an annual basis T-cHP and Renewable Energy
~
57
IhAlV If
~~
-
Net Zero Energy • Efficiency is still "job one" • Reducing energy requirements through energy efficiency is generally less expensive than renewable energy • Make the building as efficient as possible until renewable energy resources become cost effective • General rule of thumb: 75% EE & 25% RE TMCHP and Renewable Energy
Power-Purchase Agreements Popular for Renewable Energy • 3rd Party finances project installation • 3rd Party sells you the solar energy produced on your site (at a known price) for 15-25 years. - They like it because it will likely payback for them in 10 years or less. • You get "green" power and a known future energy cost (lower risk) 59
T-CHP and Renewable Energy
~
59
MAINTENANCE AND COMMISSIONING
U-1
MAINTENANCE MANAGEMENT
U-2
~
What Do These Have in Common? • $lO,OOO/year savings -
Fixed compressed air leaks
• $14,OOOjyear savings - Repaired/replaced faulty steam traps • $12,OOO/year savings -
Insulated bare steam piping
• Answer: - Annual dollar savings - No capital equipment to purchase - Just attention to what is going on in your or your customer's facility and funding to correct these types of problems - In other words, a good maintenance program • U-3
~
Maintenance Management "The Stealth ECO" • Energy and dollar savings from a good maintenance management program can rival those from more well known ECOs such as efficient lighting, energy efficient motors, etc. • Problem - We learn to live with maintenance issues and they often go below our energy management antenna scan - A hissing air leak that we hear everyday, - Or an air leak we don't know about - A broken actuator - damper linkage - That water puddle below a steam pipe flange fitting • Problem - We wait until there is a breakdown before we do something • Solution - Treat maintenance as an integral part of a strong energy management program .• U-4
What Does It Take? .ssur~ (k':Vl.tly~aJ:")
UO psi
100 psi
~
318
226,.100
200,tOO
190,000
114
100,500
n,500
86,300
1/8
25,1(1)
23,100
21,100
1116
6,300
5,800
5.,300
l/32
1;600
IAOO
1,300
U-9
~
Compressed Air Leak Example· • A 1l0psig air system used for operating tools around an industrial plant has three 1/1{ leaks and two %" air leaks. The air circuit (line) IS pressurized 8760 hours per year. Electric energy costs are $0.08/kwh. • What are the annual energy costs of the leaks? •
'5'J.,.6Joo
A;tV>d~ . . . . . r/ S(VJ/;J/:5
+- 'Z--t-Le?oJ -:;.. ~ 1rOO .! p (Mf:~' >1fO°'l.. fj'DJ -:J'~ I U( L
I
U
Energy Loss from Uninsulated Pipes steam pressur~ in psig, for 8760 h/yr operation, per 100
feet of pipe .r.~~·
5000
OJ
c::
,,:1 _ _
n
E
, L.,
ro
4~.~O·I .... -
OJ
'iii ......., OJ
Water pump with suspicious (noise-floor) vibrations. Attempts to localize problem began. (Source: Oklahoma State U. Industrial Assessment Center) U - 30
Hot H20 Pump1 - Coupling - Horizontal- Vel Freq 60000 CPM 11812004 2:05:45 PM
.QtAI.U.,QQ .r:nm!§:.rm.~.
0.45·
0.4
0.35'"
,.,.
0.3.' ..,N,.
§
025
~
E
E
0.2.', .. ", ..
0.15·'
0.1
0.05·
o
o
10,000
20,000
30,000
40,000
50,000
CPM
.•:1!.*-i?:@~::?:~~i.~:~:,:~:~:::." "''OfAli' i'o'sf'ni'ili"is"rms .,':. ·~~~(~~:M~. .
Problem was later localized to the motor coupling. Repair was initiated to avoid catastrophic failure.
U - 31
"),0(
Lubricant Analysis • Lubricants (e.g., oil) can be analyzed for wear and tear on process bearings, gears, etc. • Draw a sample of lubricant, send it in to a testing firm for analysis and receive a report regarding machine wear, particle analysis, potential failure information. Start analysis program early in equipment life and develop trend data. • Company can then make decisions about equipment performance, planned parts replacement, etc. • Allows company to "see into the future" to avoid catastrophic failures and use PM rather than CM to management equipment. •
COMMISSIONING
U - 33
CBECS DATA
,,
* Commercial Buildings Energy Consumption Survey (US DOE)
Source: Energy Performance Pitfalls., Building Operations Management, p.43, March 2002
U - 34
CBECS DATA Energy Star
1995 CBECS
2000
(Top 25% (Bottom 25%
1995CBECS
Economizers
70'*
30°,{
75%
VSDs VAV EMS
55%
20,*
45%
70'*
35%
65%
80,*
25Q,{
55%
60% 10O/C * More Data Given - Not Presented Here
Motion Sensors
20%
Source: Energy Performance Pitfalls., Building Operations Management, p43, March 2002
u - 35
Discussion • Why do inefficient buildings often use higher technology than more efficient buildings? • How can these efficient buildings with little high technology compete with Energy Star buildings who are efficient and use higher technology? The lesson: Technology alone does not ensure an energy efficiently operated building. Management and the operators can have the most significant impact on building energy use and cost.
U -36
Do It Right The First Time And Keep It There Commissioning The process of ensuring that systems are designed, installed, functionally tested, and capable of being operated and maintained to perform in conformity with the design intent ....
begins with planning and includes design, construction, start-up, acceptance and training, and can be applied throughout the life of the building Refs:
ASHRAE guidelines 0-2005 and 1.1-2007, others U-37
Like a Ship Commissioning •
Before a ship is commissioned and accepted into the U.S. Navy, it undergoes a series of tests and sea trials to ensure the ship can operate and fight according to the design intent
• A series of operational and test plans are drawn up, reviewed and approved by the owner (U.s. Navy) and/or owner's representative • The tests and trials (conducted alongside the pier and at sea) are performed by the builder and ship's company • Fixes and adjustments are made. Re-tests are conducted. • When the ship has met appropriate standards, the ship is accepted by the Navy • Six months - one year later after initial operations, the ship is brought back into the shipyard for tweaking and updating
• U - 38
Benefits of Commissioning • Buildings and systems that function as intended • Operators that know how to operate the building effectively • Greater occupant comfort • More satisfied and productive occupants • Reduced energy consumption and lower operational costs • Reduced environmental impact • Others . . . •
Lack of Commissioning Examples • Air side economizers: 50% of the time do not function properly (ASHRAE says 70%) • Chilled water pumps directly connected to condenser water return lines •
Parallel pumps with some connected backward
•
Mislabeled pipes (supply and return labels wrong, arrows pointing in conflicting directions, others)
• Air handling units (AHU) with belts completely absent (motor still running) • One study found 650 such discrepancies • An effective commissioning program can identify these types of problems and allow them to be fixed in a timely manner before the owner accepts the project • u -4{}
Recommissioning (May see it called Retrocommissioning) The process of periodically repeating commissioning activities as needed when building are modified, additions are made and/or significant time has passed. Helps existing buildings attain a higher level of effectiveness and efficiency by ensuring all systems operate as intended. Difficult to bring to "like new" performance, but still a desirable goal. • U -41
Real Time Commissioning Continuous (perhaps real time) monitoring of building systems to determine when further commissioning activities are needed. Necessary since systems tend to drift out of control and management needs to know immediately when that occurs.
U-42
Seasonal Commissioning • Seasonal commissioning involves commissioning activities that occur seasonally, such as prewinter and pre-summer checks and verification of HVAC equipment. • We see this in our personal lives when we hear commercials that encourage us to "get ready for winter" by having a pre-winter service check-up on our HVAC equipment
U-43
ot4r.
Time Line ~
The chart depicted below is one concept of how these fit together. There"is nothing accurate about the actual placement of thes~ activities on the time line; the chart is intended to convey,t~OU9ht only. DesIgn
Design
Construction
'":~m~~'~
TAB
Owner Ac'_:':-;:_"_:>"_:< __
>-
. . . . .!
::a'}::i~?
. . . . . . . . . . . K:!)
·~'Alg6f:it1ims.J]af"l;bE!·adj(j$t~~,·wlatjljelyecisiIY··.. ·.t.
,schedule·forl.!tilitrPlants/mechal'Jical.ande(ect~it:ar.·e~I!.lipmen~'
.•.•..•.• l:Jl:I~e9.Prir~~tirn~i~ClIl'!ndartjmfliOrphysiCal:parafjleters,;:'·.··
•. y~~~~~!:~ffi?!;'il¥~~;jf i! ·2·.!~~~~:~:,i~;\!I!!lill!I'~~ .... / .•~'
Section V BAS & Controls.Draft Rev 1-1-13.pptx BAS & Control Systems V - 61
Review: BAS
Section V BAS & Controls.Draft Rev 1-1-13.pptx BAS & Control Systems
Section V BAS & Controls.Draft Rev l+13.pptx BAS & Control Systems V - 63
Section V BAS & Controls.Draft Rev 1-1-13.pptx BAS & Control Systems V - 65
Overall Recap
Section V BAS & Controls.Draft Rev !-l-13.pptx BAS & Control5ystems V - 66
Alternative Financing Comprehensive CEM Training Program for Energy Managers
W-1
Why? • Takes $ to Save $ • Available Resources &. Programs • May be the Only Way ...
W-2
Alternative Financing for CEMs
I~I
What Will We Cover? • 4 Basic Ways to Finance - Equity - Borrow - . Lease - Performance Contracting
• Performance Contracting -
Definition Contractors Financing Costs Benefits vs. Risks
• Measurement & Verification - Definition - Established Guidelines - Approach Options - Periodic Audit & Reconciliation - Value
• Review W·3
What Will We Learn? • General Financing Alternatives • Performance Contracting Aspects • Energy Savings Measurement & Verification
W-4
Alternative Financing for CEMs
4 Basic Ways to Finance • Equity
• Borrow • Lease • Performance Contracting
W-5
Equity • Simplest. • Usually Most LCC Effective • Owner Assumes All Risk
W-6
Alternative Financing for CEMs
I~I
Borrow • Many Resource Options • Owner Assumes All Risk
W-7
larcrl
Lease • True Lease I Rental - Tax Deductible ;t. - Won't Own at End of Term • Capital Lease - Can Depreciate Asset - Agree to Buy at End of Term ("rent to own")
W-8
Alternative Financing for CEMs
After Tax Cash Flows • Financing Method Can Dramatically Affect LCC on ATCF • Tax Advantages With True Leases and With Municipal Bonds (when appropriate) • Example ATCF With Calculated Present Worth For All Methods in Appendix (obviously, if interest rate, MARR, IRR, is different, numbers would be different)
Performance Contracting • Definition • Contractors • Financing Costs • Benefits vs. Risks
W-9
Alternative Financing for CEMs
Definition A contract between a building owner & a "ESCO" contractor for the purpose of saving energy $ in the owner's building(s). The contractor agrees to research, design, build & maintain capital improvements which are expected to save energy $. The owner agrees to pay the contractor from savings realized during the contract period. $ The contractor must "perform" via energy $ savings in order to be paid... Maximum Term with U.S. Federal Government Contracts = 25 Years
Before
W-10
During
After
ewerI
I
3 Classic Structures • Shared Savings - Documented Savings are Shared • Guaranteed Savings - Monthly Payments Made Based on ngs Projections with Periodic Reconciliation Against a Guaranty • Chauffage - Consistent Monthly Cost for Provision of Comfort, Illumination, etc.
W-11
Alternative Financing for CEMs
Contractors • Energy Savings Performance Contractors ("ESCOs") - Utility Companies SIEMENS JGlWNSON - Manufacturers CONTR~~ts - Independents • Services - From Initial Audits to On-Going Maintenance
. , TlWlfr
NORES(:O
W-12
Financing CostS· • Quantified by Treasury Points - Set by London Inter-Bank Offering Rate (LIBOR) - Typical = Treasury Rate + 175-225 Treas. Points (around 4.5 - 7.5% fixed APR up to 20 years) - Terms Locked at Initial Contract Signing • Lender's Risk Assessment - Contract Terms - Project Complexity - Client Creditworthiness W-13
Alternative Financing for CEMs
Benefits vs. Risks (Owner's Perspective, vs. Equity) • Benefits: - Neutral or Positive Cash Flow - Contractor Performance Incentive - Maintenance Added Value - May be the Only Way? • Risks: - Complicated Process - Long Term Commitment W-14
Measurement &. Verification • • • • •
Definition Established Guidelines Approach Options Audit & Reconciliation Value
Alternative Financing for CEMs
M&V Definition ... the process of measuring and verifying energy consumption, energy demand (if needed) and energy cost savings produced as a result of the implementation of an energy conservation measure ...
M&V Definition Savings = Baseline • Post Retrofit Energy Use ... what would have been (if not for the retrofit) ...
Alternative Financing for CEMs
~
Established Guidelines • IPMVP • DoE Guidelines • ASHRAE Guidelines
W·18
ICltfCrI
I PMVP • North American Energy M&V Protocol in '96 • Int'l Performance M&V Protocol in '97 - (Adds: Water, New Buildings & Emissions Trading) • Most Popular in Private Sector • 3 Volumes Updated in '~O, '01, '03 & '06 • Available via www.evo-world.org
W-19
Alternative Financing for CEMs
Icvrcrl
DoE Guidelines • Provided by DoE in '96 & Updated in '08 • Mostly Consistent with IPMVP
M&V(lui!ll!ijrnlS:
Meam.remellt ana Yerlfl¢sfion 1M federal Elllll'llr
''''''''
Vml0ll3,(l
• Focused on Fed. Govt. Projects • Available via FEMP at:
www1.eere.energy.govlfemp/financing/su perespcs_measguide.html IFlo~lCfCf--: ~.~ ..~·I W-20
ASHRAE Guidelines • Published in '02 • Highly Technical • Available via www.ashrae.org
Alternative Financing for CEMs
g
-
Approach Options • A: Spot Measurement
, '
• B: Continuous Measurement • C: Utility Bill Comparison • D: Calibrated Simulation
W·22
A: Spot Measurement • Applicable ECMs: - Constant Load (i.e. lighting, electric motor replacements)
• Well Suited for: - Small Projects (M&V cost hard to justify) - Fast Track Projects - Installation Verification is Most Important - Owner Willing to Assume Savings Risk
W-23
Alternative Financing for CEMs
B: Continuous Measurement • Applicable ECMs: - Variable Load (Le. HVAC, controls) - Device/System can be Isolated - Few Measurement Points Needed (Le. chiller, boiler) • Well Suited for: - Large Projects (can absorb M&V cost) - Time Available for Baseline Measurement - Owner Not Willing to Assume Savings Risk
....-lcae-te.......".·1 W·24
C: Utility Bill Comparison
~ Grou~!
• Applicable ECMs: - Any/All Within a Metered Building or • Well Suited for: - Projects Where Savings are Projected to be > 10-20% of Baseline - Aggregation of Various ECMs Within a Metered Building or Group - Fast Track Projects - Owner Not Willing to Assume Savings Risk W-25
Alternative Financing for CEMs
D: Calibrated Simulation • Applicable ECMs: - Any/All
• Well Suited for: - Projects with No Available Metered Data - Large Projects (can absorb simulation cost) - Aggregation of Various ECMs Within a Metered Building or Group - Somewhat Fast Track Projects - Projects with Anticipated Future Baseline Adjustments - New Construction - Owner Willing to Assume Savings Risk
W·26
Periodic Audit & Reconciliation • Verification IntelVals - Single Post-Installation Verification - Regular Interval Verification
• Baseline Adjustments - Can "Re-Open" - Scenarios - Negotiation
Alternative Financing for CEMs
lacrcrl
Value • M&V Cost Affects Project Economics • How Much M&V is Worthwhile?
W-2B
Cost Typical Costs
M&V Approach
(% of ECM Cost)
Option A, Spot Measurement:
,
,
1 - 5%
,,"',,",~)
Primarily dependent 011 quat'l1i1y 01 measurement pojnls.
Option B, Continuous Measurement:
3-10%
Savings are detelmined by contin!JQl.ls measurem&nts taken throughout the term 01 the contract at the device or system level. Pertormance and operations lactors are mon~ored.
Primarily dependent on qty. & type 01 $}'Slem(s) m