I am modeling a system which consists of rooftop AHU's that serve
multiple VAV boxes in a classroom/office building. The AHU's are served
by chilled water and hot water loops for conditioning. The problem I am
having is that the systems are coming up in the SS-R report as having
large amounts of unmet hours. Even if I try to manually add heating to
the systems there is no affect on the hours. I have attached the pd2 and
inp files. Any suggestions would be appreciated. Thanks
Brett M. West
Wrong .inp file. send out the one without "- Baseline Design" after your file name
Timothy Howe, MS, LEED? AP
Sorry. Here is the correct inp file.
Brett M. West
Brett,
I think you might want to consider raising min. cfm in the rooms with
unmet heating load hours. Thanks!
Lan
What is your preheat coil design leaving air temp, right now you have it set to the default 45?F and with the reheat only providing a 30?F and the supply flow locked in your heating air temp can only be 75?F.
soooo... Q = CFM * 1.085 * Delta T
You have it so both the cfm and delta T are set, therefore your Q is limit to those parameters. You can either increase the preheat LAT so you get a greater delta T or remove the design CFM supply flow you have entered.
Timothy Howe, MS, LEED? AP