[Equest-users] Energy Recovery

[Patrick J. O'Leary, Jr.]

how are you controlling the erv/energy recovery?  the default is for it 
to run when the supply fan runs.  this will cost you more in energy than 
it saves.  set the control method based on a delta T between the exhaust 
air and the outside air you'll see the savings in cooling mode.  in my 
climate zone (2b/southern arizona) the best delta t i found is 27 d f.

once you set up the erv to run based on a delta t you can set up some 
parametric runs (set up one & then copy & rename it in the .inp file to 
save time) to try different delta t values without having to change each 
hvac unit every time you want to try a different delta t.

On 11/14/13 12:30 PM, Simge Andolsun wrote:
> Dear eQuest users,
> In my models, I realized that using energy recovery in the cooling 
> season always gives higher cooling energy consumption results than 
> turning off the energy recovery and using economizer only instead. I 
> tried using OA Heat/Cool with Bypass OA or Bypass Exhaust thinking 
> that such configuration would capture the best benefit of energy 
> recovery and let the outside/exhaust air bypass when economizer is 
> more beneficial. Then, I read in the eQuest manuals that this 
> configuration still lets the energy recovery run when it is not 
> beneficial in warm months and just opens up the economizer dampers to 
> compensate for the unnecessary heating of the outside air. So, the 
> loss caused by the energy recovery eats up the benefit that is 
> provided with the economizer.
> Thus, I thought, may be, I should use two separate files to maximize 
> the benefit from both the economizer and the energy recovery. The 
> first file would be for heating (with OA Heating) where the energy 
> recovery would be on whenever it can heat the outside air. Then the 
> second file would be for cooling where there would be no energy 
> recovery but the economizer would be available whenever the outside 
> air is favorable for cooling. Finally, I would get heating energy 
> consumption from the heating file and the cooling energy consumption 
> from the cooling file.
> The only thing that stops me from following this approach is that I am 
> wondering whether there was a logical reason why bypass configurations 
> of eQuest give higher cooling energy consumption than the economizer 
> only case. Shouldn't they be giving exactly the same cooling energy 
> consumption? Is it because part of the outside/exhaust air is being 
> bypassed in the bypass configurations instead of fully? or may it be 
> because it is known that setting the energy recovery and 
> economizer for the best benefit is pretty hard in reality and that's 
> why it was assumed that it would not function ideally? Or, is there a 
> completely different reason that I do not know?
> Would you please help me with this question?
> I'd appreciate it very much.
> Thanks,
> Best Regards,
> S. Andolsun, PhD
>
>
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