I am working on a project that has energy savings on the domestic water heater for the service water heating due to low flow sinks and lavs. We have been asked to provide calculations to justify the energy savings on the energy model. The spreadsheet I have attached shows the calculation proving our savings however I am having a hard time connecting how eQuest models this compared to the spreadsheet along with matching the energy consumption values from eQuest and the spreadsheet.
What should be the proper inputs for the Service Water Heating system be?
Any suggestions? Thanks!
BASELINE REPORT- BEPU Building Utility Performance WEATHER FILE- Chicago IL TMY2
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TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT
LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL
------- ------- ------- ------- ------- ------- ------- ------- ------- ------- ------- ------- --------
EM1 ELECTRICITY
KWH 94936. 0. 159052. 0. 177219. 0. 33723. 140910. 0. 0. 1857. 10821. 618518.
FM1 NATURAL-GAS
THERM 0. 0. 0. 33591. 0. 0. 0. 0. 0. 0. 0. 0. 33591.
TOTAL ELECTRICITY 618518. KWH 13.449 KWH /SQFT-YR GROSS-AREA 13.449 KWH /SQFT-YR NET-AREA
TOTAL NATURAL-GAS 33591. THERM 0.730 THERM /SQFT-YR GROSS-AREA 0.730 THERM /SQFT-YR NET-AREA
PERCENT OF HOURS ANY SYSTEM ZONE OUTSIDE OF THROTTLING RANGE = 0.3
PERCENT OF HOURS ANY PLANT LOAD NOT SATISFIED = 0.0
NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES.
PROPOSED REPORT- BEPU Building Utility Performance WEATHER FILE- Chicago IL TMY2
---------------------------------------------------------------------------------------------------------------------------------
TASK MISC SPACE SPACE HEAT PUMPS VENT REFRIG HT PUMP DOMEST EXT
LIGHTS LIGHTS EQUIP HEATING COOLING REJECT & AUX FANS DISPLAY SUPPLEM HOT WTR USAGE TOTAL
------- ------- ------- ------- ------- ------- ------- ------- ------- ------- ------- ------- --------
EM1 ELECTRICITY
KWH 62239. 0. 159052. 113974. 113369. 0. 41385. 66957. 0. 0. 1572. 3721. 562270.
FM1 NATURAL-GAS
THERM 0. 0. 0. 18311. 0. 0. 0. 0. 0. 0. 0. 0. 18311.
TOTAL ELECTRICITY 562270. KWH 12.226 KWH /SQFT-YR GROSS-AREA 12.226 KWH /SQFT-YR NET-AREA
TOTAL NATURAL-GAS 18311. THERM 0.398 THERM /SQFT-YR GROSS-AREA 0.398 THERM /SQFT-YR NET-AREA
PERCENT OF HOURS ANY SYSTEM ZONE OUTSIDE OF THROTTLING RANGE = 0.7
PERCENT OF HOURS ANY PLANT LOAD NOT SATISFIED = 0.0
NOTE: ENERGY IS APPORTIONED HOURLY TO ALL END-USE CATEGORIES.
William Mak
Hi Will,
Just put the gpm value of your new service water system into the process
flow input on the Process/DHW tab of your DHW loop. The schedule for usage
is there too, but will be the same in both cases.
I would not expect a hand calc to match the eQUEST calc in any case, as
eQUEST will likely be using a much more complicated schedule.
Best,
Carol
If you are in the detailed mode, you can open up the DHW loop, and see the
assigned flow, in GPM. This, along with the flow schedule, represents the
amount of hot water the system is using (in general, the GPM is entered as the
maximum flow, and the schedule reduces the flow as necessary). To simulate the
savings form the low-flow faucets you can either reduce the overall GPM, or you
can edit the schedule. Both would result in a yearly reduction of DHW.
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Eddie Corwin, Energy & Sustainability Engineer