Uncontrolled heat gains

Question

Hi,
I am using Hevacomp V8i to model a residential development. The issue that I am having is with the heat gains. I have modeled the rooms assuming that they will be cooled in the summer to a certain temperature - which you can simply input this temperature. Is there a way to model the rooms to see the effect if there is no cooling in place. Does anyone have any experience on doing this?
Thanks in advance
Sarah

Duncan Brown · Accepted Answer

Sarah 
 
I think you should be considering the Summer calculation. 
 
Regards, 
Duncan

José Alberto Gil Machín · Answer

Hello again Duncan: 
Regarding the Summer temperature calculation, I think the software gives the air temperature instead of the resultant temperature. If I am correct, is it possible to obtain the resultant temperature using the Summer calculation? 
Another question a bit different: when I do the Cibse Heat Gain calculation, why do I have different gains from the casual loads if I use the air temperature than when I use the resultant temperature? (If I have to create a new question regarding the last question, please let me know)

Stephen Brown · Answer

Hello, 
 Please post your second question regarding CIBSE Heat Gain to a separate thread and I will try to answer it there. 
 With regard your question on Summer - The Summer calc uses Operative Temp as defined in CIBSE Guide A5 Section 1.2.2. This equates to Air temperature for the purposes of our calc and comfort conditions. 
 There is scope in CIBSE to calculate Resultant Temp but the conditions for this are where there is less than 0.4degC between the Operative Temp and Mean Radiant Temp. As such there would be very little difference between an Air or Resultant Temp as Resultant Temp is made up of 1/2 Air and 1/2 Mean Radiant Therefore we do not consider Resultant Temperature for the Summer calc. 
 Hope that helps. 
 Regards 
 Steve