Snow Problems

[dar]

relatively new installation research building that uses chiller that supplys chilled water to coils at 50*f with face and bypass steam system for heat. The problem Im experiencing is the plenum chamber seems to be to short and on heavy snow days the plenum accumulates lots of snow that saturates the filters and slings freezing water and trips the freeze stat any suggestions on how could remedy.

[Andy]

Hi,dar
I take it that the snow is comming in from outside? The chilled water is at too high a temp to freeze moisture from the air.
Regards. Andy.

[dar]

Yes Andy the snow is coming from outside theres a short space between the outside wall and the plenum chamber. about 3feet. after which the filters are located which are currently paper type 24"times24"by2" after the filters there is a heating coil which uses steam at 13psi which is a face and bypass type system a problem i beleive is the configuration of the steam coil only directs heat downstream of the coil and none of the heat radiates back towards the plenum chamber and as a result im getting piles of snow at filter supply side which being paper buckle and allow freezing water to reach freezestat tripping out unit.

[frank]

The steam coil after the filters will be either pre-heat or heat and will offer no protection to the filters at all. Protection for the filters (and for the steam coil if it is off) should be handled by a frost coil or heater tape prior to the filter and should be controlled by a freeze stat set at +5C or thereabouts.

Without frost protection you are in danger of losing you steam coil if it is ever turned off.

Frank

[Gary]

If I understand correctly, we are talking about the fresh air intake going into a mixing chamber. I would suggest a hood on the outside.

[twcpipes]

Questions:

1. What is the cfm entering the duct from outside?
2. What size is the duct?
Thanks, Tom

[abcdefg1675]

Couldnt you use some sort of Anti-freeze in small amounts?