I've never understood why doe2 produces zero values, like in the snippet
below. By the time the simulation reached March it reported a good value for
every hour through to the end of the year.
MMDDHH EL1 West EL1 West
Perim Z Perim Z
ZONE UNIT
TEMP MIX HUM
F PERCENT-
RH
----( 6) ----(40)
1 1 1 69.2 0.0000 <
1 1 2 70.2 0.0068
1 1 3 69.1 0.0000 <
1 1 4 70.2 0.0066
1 1 5 69.5 0.0000 <
1 1 6 70.2 0.0061
1 1 7 69.7 0.0000 <
1 1 8 70.2 0.0064
The variable being tracked (mixed air humidity ratio) is supposedly a valid
selection for a system type I've used (heat pump).
Any ideas?
Thanks,
Shaun Martin
Shaun,
I think you're calling for a hourly value that is computed only when the
system is on. Check the system part-load-ratio to confirm. If you really
need the humidity ratio during those hours, you can take the outdoor HR
but you might need to adjust for the hourly latent heat gain.
Joe Huang
So, what constitutes the system being ON? Every hour from March to Dec
reports a non-zero value, which suggests that a cycling system is considered
ON. Is it possible it takes from Jan through the end of Feb for the
simulation to stabilize?
I'll check the part-load, maybe there is some threshold before a value is
given.
Shaun
Shaun,
In DOE-2 lexicon, ON means there was a load requiring the system to be
turned on at some point during that hour, the amount is indicated by the
part-load-ratio, 1.0 meaning completely on, 0.0 meaning completely off
that hour. I'm sure the hourly cycling you're seeing is NOT for the
simulation stabilizing. I have seen such cycling on occasion, but
mostly with ventilation, not heat pump operations. What did you put
for the throttling range?
Joe Huang