Central AC question for any HVAC folks (or anyone else)

Lil'Abbey
Lil'Abbey Posts: 50
edited May 2010 in The Clubhouse
I'm having an issue with my central AC. It cannot seem to get the temp down to where I would like it - 71 degrees. Last night when I got home from work the temp in the house was 76 (AC was turned off all day). I set it to 71 and it ran continuously for 6+ hours before it could get the temp down to 71. This has never been an issue in the past. It could always get the temp down to where I would like it in a short period of time and then after that it would cycle on and off to maintain. There is cold air coming out of the vents but I'm not sure how cold it chould be as I never really paid attention to this before.

The AC is a Rheenm and is 3 years old. I checked the cold air returns and they are clean and the furnace filter was replaced last night after the unit was running so long even the the old one looked ok. I'm about to call the HVAC people but just wondering if there is anything else I can check?
Post edited by Lil'Abbey on

Comments

  • Willow
    Willow Posts: 10,999
    edited May 2010
    How big is your home and how many floors do you have
  • tcrossma
    tcrossma Posts: 1,301
    edited May 2010
    Is the compressor running, or just the fan? I'm no HVAC expert, but that definitely seems like way too long to cool down a house from 76 to 71.
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  • Lil'Abbey
    Lil'Abbey Posts: 50
    edited May 2010
    Home which is 3 years old is 1 floor with a loft. About 1800 sq feet plus another 1000 sq feet in the (unfinished) basement.
  • BlueMDPicker
    BlueMDPicker Posts: 7,569
    edited May 2010
    Sounds like it needs the refrigerant checked.
  • Willow
    Willow Posts: 10,999
    edited May 2010
    it does seem like a long time for that amount of space. Are all your vents in the basement closed? you could be pusching lots of cold air where it's not needed. Is your breaker on for the AC? some people turn it off during colder times. if all the above are good to go, you should put in a call. 3yrs though seems like you should not be having an issue with the coollant. I'm no expert
  • Lil'Abbey
    Lil'Abbey Posts: 50
    edited May 2010
    Willow wrote: »
    it does seem like a long time for that amount of space. Are all your vents in the basement closed? you could be pusching lots of cold air where it's not needed. Is your breaker on for the AC? some people turn it off during colder times. if all the above are good to go, you should put in a call. 3yrs though seems like you should not be having an issue with the coollant. I'm no expert

    Agree - it should not take that long for it to cool down the house. Since the basement is not finished there is only one vent and it is located on the top part of the furnace. It is always closed. The breaker is on as the AC was working fine earlier in the week and it is still blowing cold air. Just not sure if it is as cold as it used to be.

    Looks like I'll be putting a call in.
  • sda2mike
    sda2mike Posts: 3,131
    edited May 2010
    maybe instead of turning it off, kick it up a few degrees when you leave. the humidity will be handled thru out the day, making the temp reduction easier when you get home, homey;)
  • Lil'Abbey
    Lil'Abbey Posts: 50
    edited May 2010
    sda2mike wrote: »
    maybe instead of turning it off, kick it up a few degrees when you leave. the humidity will be handled thru out the day, making the temp reduction easier when you get home, homey;)

    Thanks..I actually did that this morning. Left it on and at 75 degrees. I'll see what happens when I get home later.
  • Willow
    Willow Posts: 10,999
    edited May 2010
    sda2mike wrote: »
    maybe instead of turning it off, kick it up a few degrees when you leave. the humidity will be handled thru out the day, making the temp reduction easier when you get home, homey;)

    This is what we do, leave it on when we know its going to be hot. It goes up during the day and when we come home it is set for another temp as well as bed time (we like it very cool at night).
    My mother in law turns hers off if she leaves the house. Making it use more engery and take longer to cool. (I keep telling her to leave it on)
  • Huck344
    Huck344 Posts: 453
    edited May 2010
    As mentioned previously, it sounds like either the compressor or the coolant. Put your hand in front of one of the vents. If air is blowing, but it is the same temperature as the room, than it is most likely a coolant issue (possible coolant leak). The air blowing out of the vents should be about 10 degrees cooler than the inlet at the register.



    I am assuming that you have a properly sized compressor.
  • Lil'Abbey
    Lil'Abbey Posts: 50
    edited May 2010
    Thanks for all the tips...I'll give them a try when I get home later.
  • greenranger
    greenranger Posts: 44
    edited May 2010
    Go outside and look at the A/C unit a see if the coils are clean no buildup of cottonwood or dirt.If it is dirty the A/C cant exchange the heat for cooling.Also any ice/frost on the big pipe with insulation? Green
  • obieone
    obieone Posts: 5,077
    edited May 2010
    When you get home, here are some things for you to check: 1. The suction line, which is the larger of the 2 lines leaving the indoor coil, If that has ice on it, then it might be low on r22/ r410. 2. Go outside, disconnect the power from the condensor(outdoor unit), then turn the a/c on at the t-stat, go back outside turn the power back on to the condensor, and see and LISTEN to what happens. If only the fan starts, then the compressor might be out. IF it is, it should be covered under warranty. JUST the compressor, not the labor.
    I refuse to argue with idiots, because people can't tell the DIFFERENCE!
  • nebborjk
    nebborjk Posts: 425
    edited May 2010
    Are the supply or return air registers blocked? Are the filters dirty? I'd have a pro come out and check the refrigerant.
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