Modeling one boiler serving DWh and heating

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dear All,


i am working on a mixed used project in which the domestic water heater and the heating and being fed from a single loop which is hot water loop.

the boiler is feeding several storage tanks and in the appartments there is a decoupler on which two pumps are installed one for space heating (baseboard) and another one for the DWh return.

i tried  HAP 4.5 and Equest 3.64 and i didn t find how to add a boiler to DWH as:

  1- in equest the electrical water heaters are only gas or electrical type .after searhing the help i found that i can let the air system being fed from the DWH loop but still i couldn t connect this loop to a boiler.

 2- in HAP i can only model the domestic water heating by providing a schedule on the LOAD and no boiler is attached.


as per LEED requirement for the modeling of DWH system(ASHRAE 90.1-2007 appendix G paragraph G.3.1.11 it is clearly mentioned that the source of energy for the DWH system in teh baseline should be the same as the proposed system.

can anybody tell me how to model this combined heating system for LEED.




maher's picture
Joined: 2010-10-31
Reputation: 0

I'm starting to learn that it may not matter that eQUEST requires a separate domestic hot water system for commercial and residential. Just note the improvements in the proposed model. Add any narrative required to explain the inputs. My project has three hot/chilled water systems but the previous engineer that worked on the project used one system in the baseline and proposed model.

A question for the group, Can you do the LEED requirements using just the Simple Wizard? I have a very simple three story row house.

ChuckLohre's picture
Joined: 2012-01-08
Reputation: 0

I agree with your statement. When 90.1 says that it must  be the same source energy, it means that you can add a separate boiler for the Domestic hot water. However, it has to be the same fuel type, which is typically gas or electric (so if you have some sort of hybrid system that has some gas, you still need to use gas).

To answer the other question:

No, eQUEST doesn't really work for the LEED compliance in the Wizards. I have never had any success with it when I reviewed what it did myself. I mean, it doesn't even get the R values right, and that's the easiest part for the baseline building.

Bob F's picture
eQUEST UserLEED EA Credit 1 TrainingTRACE 700 User
Joined: 2010-06-30
Reputation: 18