Air Make Up unit with steam - design
Air Make Up unit with steam - design
(OP)
I have a requirement of an outdoor Air Make Up unit. Air capacity: 11,000 cfm. Location Toronto: Ontario. Room is does not have human unoccupancy (Indoor Temp: 65 Farenheit). I am exhausting all the air with negative pressure in this mechanical room. Medium pressure steam (50-100 psi) is available at this floor. Therefore its availability dictates the use of a steam coil in the unit.
I have a few questions in this regards:
Can I place the unit outside where it can be as cold as -30 degree centigrades?
How much steam pressure is good enough and how do I size my unit/coil?
I have a few questions in this regards:
Can I place the unit outside where it can be as cold as -30 degree centigrades?
How much steam pressure is good enough and how do I size my unit/coil?





RE: Air Make Up unit with steam - design
The main thing is to drain the coil of condensate under all operating conditions, especially low load, when the outside air is near the freezing point. During very cold weather, the steam valve tends to be open to meet the demand, so there's always pressure to keep the condensate flowing. The coil needs to have a gravity drain to a vented receiver for the condensate, and a vacuum breaker.
Spirax Sarco's main office in Canada is in Toronto. I'm sure that someone there would be happy to get you a copy of "Hook-Ups", which has (among many other things) specific information on installations exactly like yours. A coil manufacturer would be happy to make a recommendendation about the actual coil itself.