Hello All,

I am modeling a packaged single zone with ERV in phoenix, AZ on a
facility that is 24x7 and has more than 75% OA.

When I apply ERV, the fan energy increases, a slight savings in the
cooling energy, which I can understand. However, practically there is
zero heating consumption. Obviously, something is wrong. Here's a screen
shot of my input at the ERV tab. I tried both with leaving the design OA
flow/Exhaust Flow blank and with specifying a value - no change - they
produce zero heating consumption.

I did just a portion of the building in Trane TRACE and it did the same
thing first - practically no heating energy consumption. Then, thought
maybe this is what is happening:

1. Winter outdoor air is at say 30F

2. Space exhaust air temp is at say 66F

3. If the ERV effectiveness is 76%, then ERV could raise the OA
from 360F to 57F.

4. If the required space temp for winter is 68F.

5. Then, are the people load, lighting load and plug load
providing the rest of the heat from 57F to 68F - since this is a 24x7
facility?

It turns out in Trane Trace, if I knock the people sensible and latent
to 1 btu then I am seeing a significant space heating energy consumption
with ERV (still below my base case without ERV).

I tried this same thing in eQuest - didn't work - no change in heating
energy consumption.

I searched through the list and one other user has experienced similar
results but no solutions yet.

Any help would be greatly appreciated.

Thanks,

Prem

Premnath Sundharam, AIA, LEED AP BD+C, BEMP, CEM