Forced Ventilation - Frost heave protection (warehouse)

Hi all,

Following on a post "warehouse frost heave protection" - I have selected the forced ventilation as the solution.

My concept design for the -25C Freezer includes 30 PVC pipes of 100mm diameter.

My next question is fan selection - I assume it is based on static presssure.

What is the maximum flowrate thru the PVC pipes?

Does anyone know which chapter in Ashrae this information might be? Or any other source of information?
Any tips/drawings would really be appreacited.

Thanks

SAMIAN
ASHRAE R13 "Design of Refrigerated Facilities" recomend the heat from earth about 1.3 BTU/h for ft2. I will take 2 btu/h/ft2

According with the propieties of air in your location you can figure out (in and out) the flow rate required
q=flow air x delta h
Ihope this help
regards
Gwapa

Hi Gwapa,

Thank for the ASHRAE link.

I have used the equation as you have pointed out.

ok according to realistic experience, a 6 air change per hour per gross area is needed to fully ventilate the warehouse.

This is used base on 1 of my warehouse having condensation on the top of the concrete ceiling with a a 700mm height space wedge in between my insulation panel

How do you put the PVC pipes make the heat exchange to avoid frost heave? Metal pipes are good condutors. Slotted or holed PVC pipes can work if the natural / forced air is in contact with the concrete through holes.