[EnergyPlus_Support] Purchased Air vs. PTAC

["anarui.oliveira" <anarui.oliveira@xxxxxxxxx>]

Hello all.

If (for cooling only), maintaining all other parameters in a model:

- a PTAC is fully set to autosize, and a simulation is run,
- and then it is substituted by a simple Purchased Air configuration, 
for the exact same zone and thermostat,

why is the "DX Coil Total Cooling Energy" between 1.5 to 4 times higher 
than the "Purchased Air Total Cooling Energy"?

I know "Purchased Air" is a simplification, but since we're looking 
directly at the thermal loads, and not any efficiency-dependent 
consumption variable, where does this difference come from?

Regards,
Ana Rui.



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