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Domestic Hot Water Demand in EnergyPlus [closed]

asked 2016-02-24 08:06:13 -0500

samks123's avatar

updated 2016-02-25 06:44:45 -0500

Dear Sir/Madam,

How can I obtain in the output simulation of the Domestic Hot Water Demand? I noticed that on my model (attached), the water consumption is too low. What could be the reason?

I have modelled in the Activities module, a water rconsumption of 150 litres per person a day.

Link to the idf file:



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Closed for the following reason the question is answered, right answer was accepted by samks123
close date 2016-02-26 02:02:29.741197


I'm just guessing here but I believe that the "Flow Rate Fraction Schedule Name" is not defined correctly. All of the WaterUse:Equipment objects have: Domestic hot water setpoint temperature: Always 55.00, !- Flow Rate Fraction Schedule Name

Followed by: Domestic hot water setpoint temperature: Always 55.00, !- Target Temperature Schedule Name

I would think that the Flow Rate Fraction Schedule Name should be a fractional schedule?

Chris Jones's avatar Chris Jones  ( 2016-02-25 07:42:41 -0500 )edit

@Chris Jones, I think you are right, I came to that conclusin yesterday. What typical values are assigned for the Flow Rate Fraction Schedule Name i toilets and/or kitchen?



samks123's avatar samks123  ( 2016-02-25 08:25:09 -0500 )edit

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answered 2016-02-25 10:37:59 -0500

Chris Jones's avatar

@samks123, the flow rate fraction schedule generally mimics the occupancy schedule. You would expect the peak domestic water flow for hours when the building is fully occupied and at reduced flow when the building is minimally occupied. For example an hourly water flow schedule for a typical office weekday: 0.05,0.05,0.05,0.05,0.05,0.10,0.25,0.70,0.90,0.90,0.90,0.90,0.90,0.90,0.90,0.90,0.80,0.65,0.50,0.35,0.20,0.10,0.05,0.05

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Asked: 2016-02-24 08:06:13 -0500

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Last updated: Feb 25 '16