Clean Room Sqft/Ton refrigeration
Clean Room Sqft/Ton refrigeration
(OP)
Hi all,
I have been reading around on this forum for many years, and finally have a question to ask for myself. Really I am just looking for a guideline to make sure I am in the correct ballpark with my numbers.
I am designing a new air handling unit for a Pharma facility, and have gotten to the point where I now want to sanity check one of my calculations. I am trying to make sure that my number for Sqft/TR makes sense of a clean room. I am getting 909 sqft/TR which seems a little light to me. With a room that has no exterior walls, windows, maybe one person at any given time, and some lights, I guess it is possible that this is correct. Does anyone know of an ASHRAE guide that would give typical ranges, just for sanity purposes?
Thanks in advance.
I have been reading around on this forum for many years, and finally have a question to ask for myself. Really I am just looking for a guideline to make sure I am in the correct ballpark with my numbers.
I am designing a new air handling unit for a Pharma facility, and have gotten to the point where I now want to sanity check one of my calculations. I am trying to make sure that my number for Sqft/TR makes sense of a clean room. I am getting 909 sqft/TR which seems a little light to me. With a room that has no exterior walls, windows, maybe one person at any given time, and some lights, I guess it is possible that this is correct. Does anyone know of an ASHRAE guide that would give typical ranges, just for sanity purposes?
Thanks in advance.





RE: Clean Room Sqft/Ton refrigeration
RE: Clean Room Sqft/Ton refrigeration
909 SF/ton does seem light, but could be right. You might want to double check the heat loads from (1) the equipment in the space and (2) the outside air requirements. These two items will increase the amount of cooling required.
I am not sure of any ASHRAE guide for typical ranges for a clean room. However, you can check ASHRAE Check Figures for a space that is similar to your application. For example, Hospital Patient Rooms according to the ASHRAE check figures have a range of 165 to 275 SF per ton. Residential spaces have a range of 400 to 700 SF per ton.
Justin K, P.E.
http://www.engproguides.com
RE: Clean Room Sqft/Ton refrigeration
There is only a very small heat load from equipment in the room, and the outside air is set at 20% right now. I will do the calcs over again just to make sure I am not missing anything.
RE: Clean Room Sqft/Ton refrigeration
RE: Clean Room Sqft/Ton refrigeration
RE: Clean Room Sqft/Ton refrigeration
I did a quick calculation just out of curiosity:
Lighting: 1.1 W/SF [100% heat load to space]
People: 143 SF/Person; 250 Btu/Hr - Sensible; 200 Btu/Hr - Latent
Miscellaneous Equipment: 3.0 W/SF [100% heat load to space]
From the above inputs, I got a result of 700 SF per Ton.
If I changed the Miscellaneous Equipment to 2.0 W/SF, then I get a result of 874 SF per ton.
Justin K, P.E.
http://www.engproguides.com
RE: Clean Room Sqft/Ton refrigeration
RE: Clean Room Sqft/Ton refrigeration
RE: Clean Room Sqft/Ton refrigeration
RE: Clean Room Sqft/Ton refrigeration
If you have chilled water cooling, it doesn't hurt to upsize cooling capacity. Someone might put a laminar flow bench or some other equipment in there someday. The benches put out quite a bit of heat. If you have DX cooling, I would lean toward undersize vs. oversize.