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Advise Needed on Cold Air Returns

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  • Advise Needed on Cold Air Returns

    We just purchased a home back in our hometown and plan on moving back there after we have everything "ship-shape".

    One of the things I noticed last week was that all but one of the cold-air returns on the first floor have been blocked off. When we did our initial walk through, I confess to not noticing because of the previous owners furniture and carpets. The inspector didn't pick up on it either, which makes me wonder if I'm missing some understanding of a particular type of forced-air heating system. Most of my knowlege in this area is pretty old, learned mostly when I used to work with my Dad, or as it applies to the furnace in our present home.

    The unit in the newly purchased house appears to be a fairly late model that I'm guessing is about 15 years old. The furnace carries the "Temp Star" brand. The generic-looking manual refers to the furnace as a "condensing upflow" gas furnace. It is also equipped with a "split system condenser" central air unit, which was added about three years ago, according to the previous owner. I think that the exchanger is located on top of the furnace and then piped to the outside compressor, etc. Also I see that the furnace combustion chamber is piped with both inlet air and exhaust to the outside.

    The thing of it is, there are cold air ducts to each of the first floor rooms. But, all of the grates have been removed (and thrown away) and plywood has been cut to fit neatly over these areas and are nailed in place and stained to match the floor (looks like heck, though).

    So the question is, did the previous owner know something I don't or was he an idiot, thinking that those grates were just ugly and he had to get rid of them or what? Does having the AC make a difference and you don't need to use these ducts any longer? Seems wrong to me, but maybe I'm the idiot.

    We are going to refinish all the floors and either replace those missing return grates or else have the floor properly fixed. But, it seems to me that those return ducts are needed?

    I had one of the local heating and plumbing places over to get an estimate on redoing the plumbing and we talked about the furnace. Because that company has connections to other businesses in the area, I also asked him about recommending someone to refinish the floors. He looked at everything carefully and never questioned the blocked return events. But when I pointed them out and asked specifically, he hesitated a bit and then responded with a "YES, they need to be opened up and all new grates purchased." While he may be absolutely correct, I might also think that maybe he just saw a chance for additional income. So, that's why I'm posting this question to all those well repected experts here.

    Your assistance would be very much appreciated!



  • #2

    Are any of the cold air returns upstairs blocked off? Its possible the owner was trying to regulate the flow of air through the home by altering the retun air to the furnace and stumbled on to a system he was comfortable with..

    Its also possible that the installer of the system you describe determined that in order for his system to work properly he did not need the over-abundance of retun lines that the original system had.

    Another possibilty exists: your assumption that the previous owner might be an idiot could be correct.

    Since this is your home town can you ask an old friend for the name of an HVAC contractor they trust. Then have them do an on site inspection to determine if these vents were blocked off for good cause or by ignorance. Who knows, the outfit they recommend might turn out to be an old friend or schoolmate. Home towns are nice that way. Best of luck with your move.
    Work hard, Play hard, Sleep easy.


    • #3

      There are no cold air returns on the second floor. I believe that's traditional because of the three houses I've owned as well as other family members homes, second floor primarily uses the stair case with a large return duct near the base of the stairs on the first floor.

      In this house (the new home) all the first floor air returns are blocked off with the exception of one in the dining room, which is on an outside wall, and even that is significantly smaller than original (floor grid replaced with one quarter-round type heat register. The house, originally built in 1887 has been "modernized" (probably several times) and has a rather "open" look to the first floor, with living room (22 x 22), dining room (12 x 16), and large kitchen w/dining area almost completely open, including the removal of all doors, even to the basement. However, the duct work is there and hooked to all the blocked off, first floor areas. I see no obviouse way for the air to be taken into the system other than through those return ducts. The house is a bungalow style with finished basement and attic.

      I was a bit suspect of the guy we had in to do the estimate for plumbing, etc. I know when the local folks installed the new furnace in my present home, they went to some extent to measure the air flow at the furnace return. When they did, they concluded I need one additional duct and included that in their estimate. I guess I need to find just a local heating expert in the hometown and have him run the necessary checks and then go from there.




      • #4
        Must be drawing or attempting to draw return air from somewhere?
        Well if the fan door pulls pretty hard (maybe even rams back to its former permanent position)while agar(several inches) and unit(even just fan on continuous) is running you prolly "sly" of return air.
        On newer furnaces you have to hold in the safety door interlock switch to check this.
        You hear any air noise?.. if you hear lots of air noise prolly to much closed up.
        You can very rarely have too much return air.
        Lots of return air enables comfort.
        cold air pulled back at hopefully low velocities to avoid the "draft" feeling.