Hello all,
Your answer to the following question will be greatly appreciated -
When we mention equipment efficiencies (by manufacturers or the default values), they are usually for full load. Does eQUEST consider the part load efficiencies of HVAC equipments?
Under Air side HVAC - Cooling - Coil Capacity/Control, I did see 'Min cycling part load ratio' and I think the default their is 0.8. Is this relevant? How about other equipments?
Many thanks and kind regards,
Shalini
Hi Shalini,
The effects of part load are taking into account in the performance curves. There are part load curves for cooling and heating EIR/HIR under the Unitary Power tab, and for Capacity under the Capacity Curves tab. On the water side you can also define curves under the Performance Curves tab. Take a look at this topic in the DOE2 help in eQUEST: "CURVE-FIT for Equipment performance."
I do not know too much about this topic but I understand that it's something that in the past has not been handled too well in DOE2. I'm not sure what type of systems you are modeling but there is a paper by Henderson, Parker, & Huang that presents alternative EIR plr curves over the DOE2 default for light commercial and residential systems. You should be able to find the paper online: "Improving DOE-2's RESYS routine: User Defined Functions to Provide More Accurate Part Load Energy Use and Humidity Predictions." I've used these curves for a "typical AC" in the past .
Hope this helps some. I'd love to hear others input on this matter.
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Alea German