SS-R Report - Part Load Hours

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I'm stumped...

I let eQuest select the size of my heat pumps, but when I look at the
SS-R report to see my unmet hours and part load performance every heat
pump is operating at maximum capacity. Not a single unit has any part
load performance. I would think this could happen if I selected the
size of the units, but if the program is sizing it, wouldn't it select a
unit that is large enough to meet capacity which would have to result in
some part load performance? There are some units that have many unmet
hours (typically heating) and others that have no unmet hours. Both
cases have no part load hours. Any input would be appreciated.

Thanks!

Alison Staudinger P.E., LEED AP

Alison Staudinger's picture
Joined: 2011-09-30
Reputation: 0

Report SS-R gives the number of hours the fans are in each part load range.
Generally, with heat pumps, the minimum fan ratio is 1, which means that the
heat pump fans cycle on (100%), then off (0%). So the report is correct.
If you have variable speed fans for this system, you need to change your
input parameters to allow the fans to cycle at less than 100%.

--
Karen

No Username provide's picture
Joined: 2011-09-30
Reputation: 200