Elementary and Middle School improvements
Baseline model setup
File type: Final Results Report Location: Prairie City, IA Role: Energy consultant and modeler Project Introduction This Report is designed to assist the Owner and Project Team in making energy-related decisions about building design. The process is analytical in nature, using tools and methods not normally part of the customary design contract. The Owner, Project Team, and Energy consultant work together to understand how the building will use energy and where cost-effective savings can be realized, through design. This project is located in Iowa, climate zone 5. The scope of the project includes renovation and partial addition. Also, there are several spaces with renovation potential. The design team likes to evaluate saving potential before making decisions. Due to the character of complicated space, several different mechanical systems are applied in the project. The analysis is compared to ASHRAE 90.1 2010. The system type is compared to the Appendix G. This information is based on a review of the design documents and conversations with the Project Team. The work flow includes following process.
The Weidt Group analyzes energy solutions using DOE-2.2, a building simulation program. The program performs thermal and luminous calculations on an hour-by-hour basis, using typical yearly climatic data, to determine the building's energy loads and system requirements. The Weidt Group gathers building description data and assumptions from the Owner and Project Team to construct the model. Some of the customized operating assumptions include the following. The energy models are simulated using the Des Moines, IA DOE-2.2 Typical Meteorological Year (TMY) weather file. This energy model is intended for comparison of relative differences in net energy use for various design alternatives, compared to a baseline condition; it is not intended for system design and/or equipment selection. In addition, the actual energy use of this building will be different from the DOE-2.2 simulations because there will be differences in the weather, operating parameters, occupancy, and other circumstances not anticipated in the model. Given those qualifications, however, this model offers energy savings estimations as good as any other means available for a building that has not yet been built. The Baseline model provides a benchmark for comparison of alternatives. The sole purpose of the Baseline is to establish a starting point for program administration. The Baseline uses building characteristics provided by the Project Team, default operating characteristics representative of this building type, and minimum performance criteria for building components or systems based upon the prevailing energy code. A Protocol has been established for Baseline criteria. ASHRAE baseline setup Appen G sys. 3 ---- PSZ-AC --- Packaged rooftop air conditioner --- Constant volume --- Direct expansion --- Fossil fuel furnace Appen G sys. 4 ---- PSZ-HP --- Packaged rooftop heat pump--- Constant volume --- Direct expansion --- Electric fuel furnace
1. Intro meeting (understanding basic building information)
New LED lighting Heat pump&DX cooling vs. Appen G sys. 4
3. Final results meeting (Finalize strategies selection and review bundle results)
New LED lighting Gas furnace&DX cooling vs. Appen G sys. 3
4. Site Verification (Construction Documents review and on-site verification)
New Addition Renovation Alternate Renovation
Building Summary Location Building Area
Prairie City, IA 54,836 sf – 27736 sf renovation, 13,300 sf alternate renovation, 13,800 sf addition Summary of Existing condition
Envelope
Exis�ng: Brick exterior finishes with CMU backup and ba� insula�on exis�ng:Punched windows with aluminum framing Florescent light throughout
Summary of Renovation
Plug Loads
Addi�on: Steel studs with metal frame wall; Exis�ng: To be remain Addi�on: storefront and curtain wall Exis�ng: To be remain Mix of exis�ng florescent llight and new LED light Typical plug loads by space type
Service Water Heating
Electric point of use water heater
Lighting
Hours of Operation Mechanical
No lighting upgrade electric heating&DX cooling vs. Appen G sys. 4 No lighting upgrade Gas furnace&DX cooling vs. Appen G sys. 3 New LED lighting Gas furnace&DX cooling vs. Appen G sys. 3
No lighting upgrade LED lighting Gas furnace&DX cooling vs. Appen G sys. 3
Energy conservation measure evaluation
Systems Summary
Glazing
Alternate LED lighting upgrade No HVAC upgrade
Alternate LED lighting upgrade No HVAC upgrade
2. Preliminary results meeting (select energy conservation measures to evaluate in model)
Typical opera�on hours for elementary school Classroom A: Exis�ng electric coil for hea�ng and DX cooling; Auditorium, Classrooms B, Media Center, Gymnasium: exis�ng Packaged variable air volume with gas furnace and DX cooling; Classrooms C: Exis�ng Packaged heat pumps with gas backup Office (New), Classroom (New): Non
Classroom A: New electric coil for hea�ng and DX cooling; Auditorium, Classrooms B, Media Center, Gymnasium: New Packaged variable air volume with gas furnace and DX cooling; Classrooms C: New Packaged heat pumps with gas backup Office (New), Classroom (New): Heat pump furnace and energy recovery
This table shows Whole Building results for Top 10 individual strategies or groups of strategies to show the best opportunities. Dollar savings affect payback, and savings accrue every year of a building’s life. Hourly Whole Building analysis allows us to present integrated results. Individual conservation and efficiency strategies can affect more than one fuel source. For example, a more efficient lighting design produces less heat. This reduction in interior heat gain reduces cooling energy needs. If cooling energy is produced by electricity, those savings are integrated into the Annual Dollar Savings above. However, that more efficient lighting may cause a need for more heating energy in the winter.
Strategy Descrip�on
How does this strategy save energy?
Ligh�ng wa�age is saved by reducing light level or increasing ligh�ng system efficiency Ligh�ng wa�age is saved by switches that allow Ligh�ng switch strategies occupants to choose lower light levels (eg. 1/3 or 2/3) Hea�ng and cooling energy are reduced by closing VAV Occupancy sensor control of outside boxes lowering ven�la�on rates when zones are air - RTU 3,4&new addi�on unoccupied Cooling energy is reduced by an increased system Best cooling systems efficiency Hea�ng and cooling load is reduced by improved window Best Fenestra�on characteris�cs Hea�ng energy is reduced by an increased system Best hea�ng systems efficiency Ligh�ng energy is saved by turning lights off when Occupancy sensor control of ligh�ng applicable spaces are empty Total heat recovery- RTU 1,2,5& new Hea�ng and cooling energy are reduced by recovering addi�on heat from building exhaust air Ligh�ng energy is saved by dimming lights automa�cally Dimming dayligh�ng in response to daylight Hea�ng and cooling load is reduced by increasing Max envelope insula�on levels and window characteris�cs Lowest wa�age ligh�ng design
Annual Energy Savings
Included
$2,446 $2,261
1
$2,053
1
$1,322 $1,234 $1,202 $1,200
1
$1,122
1
$982 $975
• Lowest wattage lighting design strategies results in the highest energy savings. • Control to outside air and other ventilation control strategies show significant heating and fan energy savings when ventilation air and conditioning are reduced with controls. • Lighting design and control strategies also contribute to good energy savings and incentives.
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Upon review of the results of the isolated strategy analysis, the Owner and Project Team created three bundles of strategies for final modeling. The 2 bundles were developed using the following the guidelines. • Bundle 1 is the current proposed design doesn’t include Alternate renovation area • Bundle 2 is the current proposed design include Alternate renovation area The Energy use is the energy delivered to the building, not including the energy for generation and transmission of electricity or gas Bundles
Savings vs Baseline No.
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EWC03
Strategy Descrip�on
Envelope Insula�on Strategies
Percent Percent KWH
R-24 wall assembly
0.3%
ERC02
R-30 roof assembly
EWRF1
White roof
2 W6801 3
Gas
Energy $
Incremental Payback Cost
Years
1.0%
$246
$6,068
24.7
0.9%
0.0%
$574
$10,410
18.1
0.1%
-1.0%
$0
$5,800
n/a
0.8%
3.0%
$755
$5,080
6.7
Glazing Strategies Clear low-e w/ argon, alum frame glazing-as designed Dimming dayligh�ng- Classroom addi�on
1.2%
0.0%
$696
$575
0.8
DGA03
Dimming dayligh�ng- Conference Alternate
0.9%
0.0%
$505
$231
0.5
DGA05
Dimming dayligh�ng- Office addi�on
1.0%
2.0%
$747
$169
0.2
DGA06
Dimming dayligh�ng- Corridor addi�on
1.0%
0.0%
$557
$298
0.5
Classroom addi�on manual dimming
0.1%
0.0%
$47
$1,204
25.6
LCCA8
Classroom addi�on vacancy sensor control
0.1%
0.0%
$47
$940
20.0
LCCL5
Classroom RTU w ltg manual dimming
0.2%
0.0%
$113
$700
6.2
LCCL8
Classroom RTU w ltg vacancy sensor control
0.1%
0.0%
$29
$547
18.9
LCCU5
Classroom UV manual dimming
0.3%
0.0%
$209
$1,950
9.3
LCCI1
Corridor addi�on occupancy sensor control
0.3%
-1.0%
$131
$1,463
11.2
LCOF5
Office addi�on manual dimming
0.2%
1.0%
$194
$216
1.1
LCOF8
Office addi�on vacancy sensor control
0.0%
0.0%
$55
$169
3.1
LCOE5
Office exis�ng manual dimming
0.2%
0.0%
$108
$216
2.0
LCOE8
Office exis�ng vacancy sensor control
0.1%
0.0%
$32
$169
5.3
LCMC5
Media center manual dimming
0.1%
0.0%
$43
$593
13.8
LCMC8
Media center vacancy sensor control
0.1%
0.0%
$42
$464
11.0
LCRA8
Restroom addi�on vacancy sensor control
0.0%
0.0%
$2
$100
50.0
LCST8
storage exis�ng vacancy sensor control
0.0%
0.0%
$0
$66
n/a
LCCN5
Conference lgt alternate manual dimming
0.2%
0.0%
$94
$628
6.7
LCCN8
Conference lgt alternate vacancy sensor control
0.1%
0.0%
$26
$491
18.9
Ligh�ng Design Strategies
L02BW
ligh�ng upgrade and new ligh�ng area 20% lower than 90.1
1.6%
-1.0%
$892
$1,317
1.5
L03BW
ligh�ng upgrade and new ligh�ng area 30% lower than 90.1
2.4%
-2.0%
$1,310
$3,002
2.3
L03CN
Conference room with alternate ligh�ng upgrade 30% lower than 90.1
0.2%
0.0%
$114
$460
4.0
L06XX
Exterior 20% lower than 90.1-2010
0.7%
0.0%
$460
$4,978
10.8
L07XX
Exterior 30% lower than 90.1-2010
1.1%
0.0%
$692
$11,347
16.4
7
Energy Use Intensity (kBTU/sf)
60.0
$1.40
Energy Use Costs ($/sf)
$1.20
50.0
$1.00
40.0
$0.80 30.0 $0.60 20.0
$0.40
10.0
$0.20
0.0
$0.00
U�lity Protocol Baseline
Bundle 1
Bundle 2
2.2
2.2
2.2
Equipment Ligh�ng
9.9
7.6
7.2
SWH
1.5
1.5
1.5
Fans & Pumps
12.9
10.9
10.7
Cooling
3.6
2.4
2.6
Hea�ng
23.0
19.7
18.5
Total
53.1
44.2
42.7
U�lity Protocol Baseline
Bundle 1
Bundle 2
Equipment
$0.05
$0.05
$0.05
Ligh�ng
$0.24
$0.18
$0.17
SWH
$0.04
$0.04
$0.04
Fans & Pumps
$0.32
$0.26
$0.26
Cooling
$0.09
$0.06
$0.06
Hea�ng
$0.40
$0.34
$0.33
Total
$1.15
$0.93
$0.91
HVAC Efficiency Strategies
MAD02 DX cooling, 13% increased EER, - RTU1,2
0.2%
0.0%
$147
$6,683
45.5
MAD14 DX cooling, 13% increased EER, - RTU5
0.2%
0.0%
$132
$3,475
26.3
MAD04 Heat pump cooling, 3% increased EER- RTU 3,4
0.1%
0.0%
$45
$875
19.4
MAD07 Heat pump hea�ng, 5% increased COP- RTU 3,4& new addi�on
0.2%
0.0%
$146
$3,110
21.3
MAD11 Heat pump cooling, 33% increased EER-new addi�on & Classroom UV
0.9%
0.0%
$604
$24,376
40.4
MPF01
Gas furnace at 85% efficiency - RTU1,2
0.0%
3.0%
$266
$589
2.2
MPF04
Gas furnace at 85% efficiency - RTU5
0.0%
3.0%
$247
$307
1.2
0.3%
28.0%
$2,647
$5,119
1.9
8
• Minimize heat loss through cost-effective insulation choices. • Reduce undesired heat loss or gain through cost-effective envelope upgrades beyond increased thermal resistance. • Manage heat gain, and daylighting through appropriate glass selection. • Reduce electric lighting in spaces with daylight, utilizing automated or manual controls. • Reduce energy use by selecting higher efficiency systems • Reduce the fan energy necessary to move design supply and return airflow to and from the conditioned spaces. As these s elections are integrated with other building systems, study needs to be accomplished early in the design process. • Reduce energy use by adjusting the volume of outside air that needs conditioning according to the actual building load or by recovering heat/cool from return air or equipment.
Ligh�ng Control Strategies
LCCA5
5
2
The Program promotes the implementation of cost-effective bundles of strategies by proposing cash incentives to reduce the added cost of implementing the selected energy conserving strategies. The bundles discussed on the previous pages were selected by the designers to cover a range of scenarios so that one of these bundles would be a likely candidate for implementation in the final building. The Strategy selection objectives include:
Dayligh�ng Control Strategies
DGA02
4
1
Results Summary
Condi�oning of Outside Air Strategies
MOA02 CO2 control of outside air- Gym MOA03 Occupancy sensor control of outside air - RTU 3,4&new addi�on
3.4%
8.0%
$2,758
$7,402
2.7
MHRT1 Total heat recovery- RTU 1,2& new addi�on
2.1%
38.0%
$4,629
$22,976
5.0
MHRT2 Total heat recovery- RTU 5 Gym
1.4%
40.0%
$4,395
$6,893
1.6
Bundle Descrip�on Bundle 1 Bundle 2
Peak kW Savings
% Peak kW Savings
kWh Savings
% kWh Savings
Therm Savings
% Therm Savings
Energy Cost Savings
Electric Incen�ve
Gas Incen�ve
Total Incen�ve
37 43
19% 22%
116,329 122,997
17% 18%
889 1,506
15% 25%
12,037 13,230
8,027 8,979
533 1,556
8,560 10,535
Verification Field verification of installed strategies by The Weidt Group, when the building is completed and occupied. Based upon Verification Report, Utility provides the incentive payment to the Owner. The Verification process is designed to assist the Owner and Project Team in knowing whether or not the strategies are installed as expected. If some of the chosen strategies are not implemented within the Selected Bundle, MidAmerican Energy may choose to adjust the incentive amount.
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