AboutJim Barnhart Expertise Fifty + years in Heating, Ventilating, Air Conditioning, Sheet Metal Manufacturing.
Semi retired since 1995,
Experience Answer questions about , residential and commercial.
Answer questions about sheet metal fabrication.
Fifty years plus experience.
No answers for oil equipment, No answers for kitchen appliances, No answers for laundry appliances.
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My current heating and cooling system has a blower box with the cooling coils in a triangular shape on top of that. The two filers are on each side of the triangle, resting on the cooling coils fins. The unit is located in a closet with a 16x23 inch openning at the bottom of the door. There is also a 2" gap between the door and the floor. The filters I use have to be custom cut to fit on the coil assembly, which makes changing them a real pain. I was told that if I sealed around the door and put a filer on the back of the louvers in the door I would not need the filters on top of the unit. Or if I made a box to enclose the coils and maintained the same size area or larger than the openning in the door, it would not have any adverse effects on the system and would actually be better than the filters sitting directly on top of the unit.
In your expert opinion would either of these suggestion work, or are they so much hot air? (pun intended)
Answer -
Tim,
You didn't tell me what your heating/cooling unit is? Gas furnace, Electric furnace, or a Heat Pump?
Dose the supply duct go down through the bottom of the unit through the floor.
Follow up info;
Sir:
Sorry, it is an electric furnace Model E1E Series made by Nordyne/Intertherm with a Bryant heat pump model#663CJX036. Supply air is down through the floor.
Answer -
Tim,
Either of the suggestions would work.
What you really need for return air is 200 square inches of free area give or take a few inches.
The 23X16 opening in the door is plenty big enough if there is no grill or louvers blocking off that space, the 200 square inches needs to be free area.
EXAMPEL: A 20 X 20 filter has a face area of 400 square inch area but only 50% of a filters face area is free area which would be 200 square inches.
Calculate the free area in your door opening to see if you can get the 200 square inches.
Make sure that the space going up between the door and the air handler is at least 200 square inches.
Jim,
Thank you for your help. The current openning in the doors does have a grill over it and is at the bottom of the door. I found the service manaul and it say the grill should be at the top or above the air handler.
Would it be better to block off the bottom and put a new openning above the handler?
What if I left it open and put a new openning above the handler, effectively doubling free air space or would that be to much air?
Also there is a small vent, about 12" dia. that leads from my living room ceiling to the ceiling inside the closet.
Answer Tim,
I would leave the bottom opening and grill as it is and install another one on the top part of the door that is the same size or as close to the same size as you can find a grill size for.
I would get a case of throw away filters 16 X 24 or whatever would work on both openings the same.
You can fashion some type of fastener to hold the filter in place.
The old type screen door springs work good if you can find them.
throw away filters have a fine coat of oil on them that catches the dust, You can get them for about $2 each, if you changed them every 30 days you would save the $4 cost for two on your electric bill.
There is no such thing as to much return air, you are getting about 2/3 of what you need now.
The vent in your living room ceiling is for cooling season and should be closed when heating, open when cooling.
The only other thing would be to stick a floor sweep or something on the bottom of the door so you don't pull dirt under.
