Shop Products
Houzz Logo Print
ct_newbie

How much of the return do you really need?

CT_Newbie
10 years ago

Our AC had a leak on an inside coil. We had several people offer several solutions. It is a York Diamond 90 and they don't make the 7" coil and there wasn't enough space for a 14" or so it seemed. What the Carrier guy ended up doing was removing a second vent from the top to gain a few inches and he some how lowered the bottom metal area which resulted in lowering part of the return that is connected to the main unit. That way, he was able to fit in a 14" coil. We left the vent on the wall unchanged. This meant that only about 2/3rds of it was really connected to the return (because it had been lowered) vs. 100%. I guess the bottom third just blows into the wall?

At any rate, I was wondering if this posed any sort of hazard as I had heard that returns shouldn't be blocked. The Carrier guy said it didn't and enough of the air passed through. Are there any problems for which I should be on the look out? Right now the AC works fine again.

Please advise. Thank you!

Comments (6)

  • bus_driver
    10 years ago

    Is the coil positioned vertically or horizontally? Sounds as if the only real change was to reduce the height of the plenum. That would not have an adverse effect. But if you are saying that the cross-sectional area of the return has been reduced, that is a very different situation. If the cross section has been reduced, post here the dimensions before the change and after. Most likely, someone here will be able to respond knowledgeably.

  • CT_Newbie
    Original Author
    10 years ago

    Hi! Thanks for your response. Since they were always talking about the vertical space issue and trouble fitting in a 14" coil, I'm going to guess that the coil is positioned vertically. I will try to measure the dimensions of the return grate. It comes out of the side of the unit and flows through a grate on my wall. (Sorry I'm not using the correct technical names for these things). Therefore by lowering the whole unit and not moving the grate, the area that flows through the grate gets reduced about a third (assuming that prior to the lowering 100% of the air flowed through 100% of the grate.

    Thanks

  • udarrell
    10 years ago

    is there any other way you can provide another Return Air into the RA plenum?

    we need to know the tonnage of the A/C & the Btuh output of the furnace so we know what the CFM airflow needs are.

    Here is a link that might be useful: Checking Static Pressure & CFM

  • CT_Newbie
    Original Author
    10 years ago

    So the dimensions of the grate on the wall are ~22.5" wide and 16.75" high.

    We have another problem. Not sure if it is related to the return Seems like the fan wasn't that strong and it was getting warmer. We've had 90+ degree heat this week. The AC guy came back and said our compressor was overheating. He said to shut it off for an hour and a half to let it cool down. I can feel the temperature rise after 15 min off. At any rate, he can't come back today so I'll turn it back on. Someone else can come back tomorrow morning. We are going to be out but will have the sitter let him in and have him call us when he is done. I asked if the guys should have caught an issue when they did the leak test. Maybe we would have just bought a whole new unit if we knew all these things were wrong. He said that back in June when we did the leak test it wasn't that hot. We just replaced a capacitor two weeks ago.

    Wish I had checked the thread sooner to ask him the above questions. The unit is in a closet in the garage so this vent is the only place it can really air out. The closet is somewhat spacious so not sure if adding something there would help. I don't think we want to cut a hole in the door and the back wall is solid concrete. I will ask my husband if he knows the tonnage and BTU.

    Thank you!

  • CT_Newbie
    Original Author
    10 years ago

    OK. It is 2 tons for the AC and I was told 24,000 BTUs. Not sure if that is different from BTUh. If so, please explain.

    Thank you very much. Will be getting a quote for the compressor tomorrow.

  • CT_Newbie
    Original Author
    10 years ago

    Just bumping this up. Given the info requested,
    *dimensions of the grate on the wall are ~22.5" W and 16.75"H
    *2 tons for the AC and I was told 24,000 BTUs
    can anyone tell me if the return (of which only 2/3rd flows through due to the repair) is adequate or if it may have caused excess strain on the compressor?

    The compressor install with conversion of air handler for new "freeon" is $3450 for parts and labor

    Thank you