Residential building sizing issue

[geshen516]

Hi all
I am working on a residential project located in tropical climate.
For Residential building, space like bedroom will have a negative thermal flow for external wall at night time, which means heat is transferred from space to ambient.
This seems not reasonable to me.

The cooling load calc process is: calculate the free floating air temperature first and then calc the cooling load.
For scenarios when air con is only turned on at night time, the indoor temperature at night under free floating case will be higher than outside; this causes the negative thermal flow from internal to external.
In such a case, the cooling load is only from internal conduction, internal heat gain(ppl, lighting, receptacle). Even the infiltration will help to take some cooling load away.

Any comment is welcome.

Thanks

[geshen516]

solved. caused by a wrong setting in room condition tab.

[lhcs]

can you tell me what is the wrong set in room? I also simulate a house intropical climate and want to learn some experences.thank u

[ZapBran]

1) Stay clear of the "building regulations" tab - this is valid for only regs in Britain, Northern Ireland and Republic of Ireland. I've noticed a really strange grid thing that suggests new zealand and singapore as well but I'd avoid that like the plague.
You want to just consider a space (or spaces) that you are supplying an air system to and deal with it like that. Residential/Commercial/SpaceShipRefuelingPodWithTivo = all the same.

[jessicamcmahon]

I have simulate the house intropical climate.In order to maintain balanced climate it is very essential to maintain thermal comfort conditions therefore thermal performance of building is need to be investigated.A thorough study of improved shading, regional variations in window size related to orientation, and adoption of adjustable ventilation and window openings is very important to maintain balanced internal and external climate.