Has anyone ever had to model an air source heat pump using a gas furnace
for supplemental heat? It is not valid to select furnace as a
supplemental heat source, although eQUEST will still run if you do so,
so I need a work-around to get accurate output. Any ideas?
Thanks in advance,
Carol
Heat pump with furnace backup
Feb 18, 2010
Carol,
You can select furnace as a baseboard heating source. (I've done this to
represent gas-fired radiant heaters that share a space with a MAU.) You
could set the BASEBOARD-CTRL to outdoor reset and use a schedule that
matches the OA temperature at which the heat pump shuts off (if that's
the case). Using this option, maybe you could select a supplemental heat
source but set it to zero capacity, allowing you to specify the MIN-HP-T
at which the heat pump shuts off. Using furnace baseboards, I wonder
what the HIR is, though, since there is no place to enter it for
baseboards.
You could also select "electric" for the supplemental heat source, put
it on a different meter, and convert the energy to therms afterward
using the efficiency of the supplemental furnace.
Regards,
William Bishop, EIT, LEED(r) AP
I am surprised that GAS-FURNACE is not valid for HP-SUPP-SOURCE. I
have used it often with DOE2.1e and the DOE2.2 Dictionary states that
you can select GAS-FURNACE. See page 395 in DOE22Vol2-Dictionary.pdf.
>> Christopher Jones, P.Eng.
Chris,
I looked at the online help and it said it was a valid choice only for a gas
heat pump. When I ran it anyway I got heat use but it was not reported in
the supplemental column. So, I am thinking that it is not a valid choice
anymore.
Regards,
Carol
Thanks, Bill! Two good options to try.
Carol