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Modeling Wall Mounted AC Units

asked 2017-04-27 01:54:47 -0600

mcdonaa1 gravatar image

updated 2017-04-27 08:25:05 -0600

In OpenStudio, if I want to model a wall-mounted AC unit, should I treat it as a heatpump? If so, will the autosize feature get me close enough for an estimate, or do I need to reduce it by some factor?

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@mcdonaa1, please use existing tags, e.g., 'heat-pump' as opposed to creating new tags.

__AmirRoth__ gravatar image __AmirRoth__  ( 2017-04-27 08:24:42 -0600 )edit

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answered 2017-04-27 07:31:34 -0600

Adam Hilton gravatar image

If it can provide heating, then yes, if not then just model it as a packaged terminal device with a cooling coil and fan. If you're looking at OpenStudio default objects PTHP has a cooling and heating coil whereas PTAC just has a cooling coil. However, the default curves for the cooling coils are different in each of them.

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Thank you, I will try that. However, it will be treated as a cooling load in the analysis the program outputs, and not labeled as a plug-load, correct? In which case, we will need to do a little assuaging of the data to more correctly label what load as plug-load and not as a dedicated HVAC system.

Should I expect there to be significantly less efficiency associated with the wall-mounted AC plug-in unit? And if so, something I will no doubt need to edit in its properties before I run the simulation.

mcdonaa1 gravatar image mcdonaa1  ( 2017-04-27 11:38:36 -0600 )edit

Efficiency depends on the unit. I've seen them up to 18 SEER for heat pumps, which is quite good, I'm sure you could find even higher though.

Adam Hilton gravatar image Adam Hilton  ( 2017-04-27 12:31:49 -0600 )edit

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Asked: 2017-04-27 01:54:47 -0600

Seen: 154 times

Last updated: Apr 27 '17