CABINET UNIT HEATER- STEAM

Brad White_203

be it Trane, Airtherm, Vulcan, whomever you use. They will have piping diagrams.

As you know, these units will need traps, usually F&T traps, dirt legs and so-on.

Typically what we specify is a control valve on the inlet (compatible with your control system, electric, DDC or pneumatic, whatever it is). On the return side, a strap-on aquastat set at 140F. On a call for heat, the valve opens, the A-stat picks up that the unit is hot and starts the fan.

Notwithstanding what the manufacturer's show, we detail in order of flow:

Gate valve, wye strainer, (reducer to control valve size) union-control valve-union, (increaser to UH connection or running size). At the outlet: Fittings to dirt leg, tee to trap. Union-trap-union, check valve optional, straight nipple for aquastat, gate valve then to condensate. Other installations vary.

Don't forget spring or neoprene isolators and seismic supports- you are adding a motor where there was none before. Also, if the ceiling is high, you may want to select a higher CFM model with bypass ports to get a lower outlet temperature. Hard enough to heat from above with 160 degree air!

Nick C.

Cabinet Unit Heaters - 2 pipe steam system

I am adding 2 ceiling hung steam cabinet heaters to an existing entrance way. They used to have radiators but have removed them. The existing system uses a 2 pipe system. The cabinet unit heaters has a pipe going to the unit heater (a steam inlet) and one pipe coming from the unit (condensate discharge). How would I be able to implement the new cabinet unit heater to the 2 pipe system. Any information would be greatly appreciated.