Water Side Heat Exchangers

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I am new to energy modeling and eQuest. I am trying to model what to me is a complex HVAC system but likely trivial to others. I will describe what I am trying to model then pose a few questions.

All ventilation air is supplied to the building via two 100% OA HRVs to zone active chilled beams and a few FCUs. There is also one zone that will be served by an underfloor air distribution system and another zone will be served by a displacement ventilation system. Radiant heating/cooling panels will also be installed in the UFAD zone and displacement ventilation zone. The system will likely be a constant volume system, but options of using VAVs for the zones served by FCUs and displacement and UFAD systems will be looked at using the energy model.

Heating is provide by a district heating source. Two heat exchanger will be used to transfer heat from the district heating to the building heating. From the heat exchangers, a primary HW loop with three secondary loops will be installed. The secondary loops will serve: 1) HRV H/C; 2) ACB & FCUs; 3) Radiant panels. All loops will be complete with two parallel pumps.

Cooling is provided via two air-cooled chillers. Water-to-glycol heat exchangers will be used to transfer building heat to the primary glycol loop which goes out to the chillers. A primary chilled water loop and three secondary chilled water loops will be installed, similar to that off the heating loops, to serve the HRVs cooling coils, ACBs and FCUs and radiant panels.

Here?s what I?ve done so far in the model.

I?ve created a dummy zone for the HRVs. All OA from this dummy zones enters the ACBs, FCs, UFAD and displacement ventilation zones. I saw on some thread to look closely how the heat is recovered from the EA using this method. How can the model be set up so all exhaust air from the zones enters the HRVs? Also, how to I model the zones served by the UFAD and displacement ventilation to be complete with radiant heating/cooling panels? Will modelling these two zones as FCUs be a good method?

On the water side, I would like to model heat exchangers. On the cooling side, there will be two heat exchangers between the primary glycol loop and primary chilled water loop. Is there a method to insert heat exchangers in this location? Or can I just add the head from the pumps on one side of the heat exchanger to the pumps on the other side and forget about the heat exchange all together? The heating water side also requires heat exchangers but I have not figured out how to insert them into the model.

Any responses would be appreciated. I am happy to have found this forum and become a subscriber and look forward to many years of discussions through the forum! Thanks

Darryl Kasun

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Joined: 2011-09-30
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