CIBSE Gain - Explanation of Calculation Results Summary

Question

Hi, 
 
 I have a question for you: I am running a CIBSE Gain calculation using Hevacomp and am having trouble making sense of the gains to the spaces. To see why there are excessive gains, I removed all internal heat gains, both sensible and latent
 i.e. people, lighting and equipment, from all spaces in the model, however, the results of the cooling load calculation show there are still gains (see screenshot). Could you provide some clarity as to what these gains are caused by? 
 
 
 Also, when I input a casual load gain, why does this change throughout the peak day when it is a constant value? 
 
 Kind regards, 
 
 John Moloney 
 Sustainability Engineer 
 Homan O'Brien &#8226; Consulting Engineers 
 89 Booterstown Avenue Blackrock, Co. Dublin, A94 P2C2, Ireland. 
 Tel: +353 (01) 2056300 Fax: +353 (01) 2056301 
 Email: john.moloney@homanobrien.ie Web : www.homanobrien.ie 
 
 
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Shane Regan · Accepted Answer

Hi John, 
 From the screenshot the vast majority of the gain is solar load, so I imagine there is glazing in this room? (If so, and if you wished to test, I would suspect that if this glazing was temporarily deleted this value would drop significantly). 
 The article below should also assist with clarifying load types: 
 CIBSE Gain Calculation - Load types - Hevacomp Wiki - Hevacomp - Bentley Communities 
 Regarding the casual load varying; you may have enabled a profile - if you wish a constant value then please ensure to untick the profile option as below: 
 
 Alternatively, you may just be seeing the hours of occupancy - the casual load will be applied to occupied hours only - ie as entered in the below: 
 
 Hope that helps to clarify.

John Moloney · Answer

Thanks for clarifying that Shane. I did indeed have the use profile box ticked for occupancy. I understand the convective and latent load are now resulting from air infiltration. 
 Kind regards, 
 John