[Equest-users] Entering WetBulb Temps in hourly reports

[Eric O'Neill]

A little background on this project first. This is a bypass VAV unit
with an air-source heat pump in the RTU, with electric reheats. I've
modeled the building with the systemtype=CBVAV, which seems to do most
things as I would like them to. I know CBVAV's aren't compatible with
heat pumps, they seem to work, for the most part. 

All my heating and cooling needs are being satisfied (0.2% outside
throttling range - confirmed in hourly reports), which seems to indicate
the system is using the heat pumps properly, however, when looking at
the results, eQuest is not accounting for that usage in the energy
totals. 

I'm getting way more heating energy reported than I would expect. When
heating, the energy imparted to the airstream by the coil is being
accounted for as essentially electric resistance (i.e. EIR=1). I can use
the hourly reports and calculate the heat pump COP based off of the dry
bulb temp entering the coil and the OAT, and then obtain the actual
usage. That's fine, and I have that working.

However, during cooling, the energy imparted to the airstream is not
being accounted for at all (essentially EIR=0). I'm trying to calculate
the COP, but the heat pump curves (from another project) are based off
of the entering wetbulb temperature and the OAT. From what I can tell,
the hourly reports don't have a coil entering wetbulb temperature
output, and I don't think I can calculate it easily.

Has anyone run into this situation and know how you can get eQuest (or
DOE2.2) to cooperate, or to output a value that I can use to calculate
my cooling EIR?

Thanks,

Eric O'Neill
Mechanical Engineer, LEEDAP
Michaels Engineering

400 Main Street, Ste 200
La Crosse, WI 54601
direct: 608-785-3328
main: 608-785-1900
fax: 608-784-2270
elo at michaelsengineering.com
http://www.michaelsengineering.com


-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/equest-users-onebuilding.org/attachments/20100122/0224301d/attachment.htm>