Trace 700 Oversizing

[jdmz]

How do you deal with the over-sizing of the cooling coil in Trace 700? Do you just assume the higher loads when making the selection? I am fixing cooling coil discharge temp at 55 F and Heating at 85F-90F.

With a VAV reheat system, the program forces heating cfm to always be 30% (default)or what is set as the % cooling minimum. If heating CFM is calculated as 500 cfm, for example, the cooling cfm is forced to be htg cfm/.3 = 1667 CFM regardless of whether 1667 cfm the cfm required for cooling. This results in massive oversizing. I wanted to get input with how everyone here is dealing with this in their equipment selection.

 

[GT-EGR]

I don’t have the program in front of me but I’ve never seen that happen. I also don’t do load calculations for heating dominated spaces too often, and typically I take trace outputs and do my own final calculations for system sizing using mostly the internal load information

I’m fairly certain that in the airflows tab there are specific line items for how the program should calculate cooling max and mins as well as heating.

If you don’t have that option, try making a cooking only system with the same space and see what happens.