Different results while using ideal air loads and actual hvac system?
I don't know if this question is asked before or not, I tried searching it but couldn't find the exact answer. I am modelling a single zone room using an ideal air loads system. Also tried using a actual hvac system to the same zone using Rooftop unit. Why are the annual heating/cooling loads using a hvac system less than the ideal air load system?( for eg. with ideal air loads district heating load 7.8 Mbtu and for system using rooftop unit 2.7 Mbtu). why a huge difference?
thanks,
Hard to pinpoint exactly without seeing your file, but what heating device is used on your rooftop unit? I'm gonna go ahead and guess a Coil:Heating:DX:SingleSpeed.
I would agree here it is to do with the efficiency of the heating and cooling equipment, they are set to 1 in the ideal loads and can be anything from 0.8 to 6 in the systems.
@Julien Marrec, I am currently using natural gas as heating unit for rooftop hvac. Can you send me your email Id so that I can email you my osm file. Thanks
Can you upload it somewhere (box, dropbox, google drive, whatever) and post the link in your post?
osm file googledrive locations: https://drive.google.com/open?id=0B3a...
the heating and cooling loads while using a hvac system should be higher than ideal air loads system or should it be other way around?