Subzero Room

[EAJ82]

If u have to design a room with temperatures between -5 C and 0 Celsius. what differs in the calculations?
my guess is that not much differs except the thermostat setting and a machine done to operate at subzero levels....any thoughts?

 

[ChrisConley]

Lots of differences, are you just looking for load calculation differences?

One item to note, is that all of the surrounding rooms (at normal temperature) will be a heat source to the cold room.

 

[chilled]

http://www.keepriterefrigeration.com/calcrite/RTcalc1.htm

 

[EAJ82]

yes load calculation differences!
it is an insulated room, unfortunately i don't think its well insulated, but didn't get the chance to test it carefully

 

[sterl]

The hardest room to design and to control at a "right" set of conditions is one just below freezing...Moisture in the air and in the insulation system and in the room contents is just never sure where to be or how to get from source to drain without bitching something up on the way by.

Key is high integrity vapor barriers and short air movements before mixing occurs. Insulation materials are not all created equal when you are working right near the "second" latent. And if the contents and locale permits, aim at depressed dew points. You can't work to 10 or 15 deg of temperature change across a coil...and you will need some means of depressing dew point of the air to below any surface in the room, if there is to be substantial traffic in and out.

Is this some form of a walk-in or a warehouse or? Is it part of a process? Is it minimally occupied or are people working in this space?