Air Conditioning Problems (how much, home builders, buying)

[JohnNHL]

Hi Everyone,

We just moved to SA and I have a question about our AC. Right now I have it set to 72 and it can't seem to get below 79, according to the thermostat. I've tried this over several days and every day it is the same, especially later in the afternoon. We cannot get the house below 79 or 80.' Is that normal for this time of year? Or is it that my AC unit is either too weak or in need of service? We have one unit on a 2300 SF house.

Also, what temp do you all set your thermostats at in the summer?

Thanks!

[RedNeckRick]

Sounds like one of three possibilities.

The unit is under-sized for your living area.
Low on Freon.
Old unit on its last leg.

[the_dimwit]

Before you call someone to come out and take a look, check the following:

1) Airflow - reach your hand up to one of the air vents and see how much air is coming out; also check to see how cool/cold it is. If there is very little air or the air that is coming out is warm/room temp, you may need to call someone.

2) Filter - make sure the filter is clean and free of major debris. If it's dirty, replace it and see if airflow increases.

3) Coil - sometimes, when an AC system is pushing really hard to keep up with outside air temps and inside humidity, the AC coil can "freeze up", meaning ice collects on the coil and prevents airflow/cooling process. You can verify this by first placing your hand on the outside of the unit (inside your house)--if it's really cold or there is condensation on the outside of the panel, you likely have a frozen coil. Turn your unit off, open the panel, and allow the ice to melt away. You can expedite melting by using a hair dryer (6-12" away from coil, warm setting only).

If none of the above works, you'll likely need to call someone out to do a health check as you may be low on refrigerant.

--Dim

[smuboy86]

We set ours at 76 in the day, and 77 in the evening, for the summer. Our house is over 2600 sq ft, and the AC has no trouble getting and maintaining temperature. If its a new house it sounds like your builder cheaped out on the unit.

[SnappyBob]

I set mine for 80 when I am not at home and 78 for when I am at home.

[L210]

Originally Posted by JohnNHL

Hi Everyone,

We just moved to SA and I have a question about our AC. Right now I have it set to 72 and it can't seem to get below 79, according to the thermostat. I've tried this over several days and every day it is the same, especially later in the afternoon. We cannot get the house below 79 or 80.' Is that normal for this time of year? Or is it that my AC unit is either too weak or in need of service? We have one unit on a 2300 SF house.

Also, what temp do you all set your thermostats at in the summer?

Thanks!

I had this problem last year because the management company contracted with an incompetent AC company. They came out to my place a half a dozen times. My AC even leaked through the ceiling after they supposedly fixed it. The thermostat was set at 75, and my townhome would regularly be above 80. It even got up to 86 degrees once. There is nothing anyone can do about my old, duct-taped AC. I really do think it's older than me, and I'm in my late 20s.

Sorry about my rant. I agree with what others said about potential causes.

[Hedgehog_Mom]

First, check the filter. You should replace the filter at least once a month.

If there are no trees around your house to shade it, and you have lots of windows, it may just be hard to get the house cool enough. I have that issue...my house is a couple years old, my ac is properly sized for it, I have the thermal barrier and lots of insulation in the attic, and my windows are double-paned. When I have the AC set on 72, it runs constantly and during the hottest part of the afternoon, sometimes it will be 76 or 77.

This year I've covered the windows in the back of the house (which faces west and gets the hottest) with foam insulation panels and the AC has no trouble getting cold enough. I've actually started leaving the thermostat on 74 or 75 instead of 72 because it's comfortable enough.

[TrapperL]

Okay John, here's how to check the output on the A/C system. You're going to need a thermometer. If you don't have one, go by most any auto parts and buy one that resembles a nail in that it has a shank and the dial is on top like the head of a nail. Total accuracy is not important in this test, differential is. Turn the unit on so it's cooling. Put the thermometer in the return air and leave it 2 minutes making sure the unit doesn't turn off. Write down that temperature reading. Go to the closest air register in a room- that's where the air comes out. Put the thermometer in the register and leave it 2 minutes. Write that number down. Subtract the air register from the return air temp. There should be a differential of 15 to 20 degrees. Any less and the unit is in need of Freon. Any more and you either have a plugged up filter or the coils in the air handler are dirty and it will need a cleaning. If you are using a pleated filter- get rid of it. Use a cheap fiberglas filter and give it a light spray of Armorall. The Armorall will stay sticky and attract dust, pollen, etc. This is how you test a normal unit. Those with variable fans and high efficiency units are different in that they can produce cooler air depending on fan speed.
You'll also need to keep curtains pulled on the sunny side of the house. If the kids are running in and out, lock the doors.....just kiddin'. Chat with the kids about staying in or out. Obviously keep windows closed. You can have CPS come to the house and do an energy audit- it's free. They can give you recommendations as to how to make the house more energy efficient. It's doubtful that the unit is sized too small but depending on the age of the home, homeowners that are knowingly going to sell will sometimes buy the cheapest they can as a replacement unit and that includes buying one too small. If the house was built after 2003, it had to have an energy audit slip before utilities are hooked up so the builder couldn't install something too small.

[Sally_Sparrow]

Originally Posted by Hedgehog_Mom

First, check the filter. You should replace the filter at least once a month.

I won't repeat all the other good advice you've gotten but wanted to second this and also add that if you smoke inside, or have pets, you should probably aim for twice a month.

As for the temp setting; we have window units, so it's a bit different, but we set them around 74 to 76 during the day but use the "energy saver" feature which cycles the compressor off when the room temp reaches what you've set it at. At night I set the bedroom unit to 70 but I am weird and I need to be in a COLD room at night then with two or three blankets. I pay $$ for this quirk.

I know they are "ugly" but having lived in places with central air vs window units I prefer the window units. I really value being able to control the temps room-by-room. We can turn the bedroom ones up to 80 on "energy saver" when no one is in them during the day, or I can have the bedroom cool whereas DD can have her bedroom warmer because she is more heat tolerant. The only thing that sucks for us in this regard is that there is no unit in the kitchen and the kitchen is tiny and away from the air flow from the living/dining room so it quickly becomes an OVEN even if you just boil a pot of pasta.

We're moving into a place with CHA and I am not happy about it! If it doesn't cool to my liking I will probably "supplement" with a window unit or two.

Oh, also, if you don't have ceiling fans, consider adding them. They are an inexpensive and effective boost to cooling your place.

[Steel Man]

Originally Posted by RedNeckRick

Sounds like one of three possibilities.

The unit is under-sized for your living area.
Low on Freon.
Old unit on its last leg.

Originally Posted by JohnNHL

Hi Everyone,

We just moved to SA and I have a question about our AC. Right now I have it set to 72 and it can't seem to get below 79, according to the thermostat. I've tried this over several days and every day it is the same, especially later in the afternoon. We cannot get the house below 79 or 80.' Is that normal for this time of year? Or is it that my AC unit is either too weak or in need of service? We have one unit on a 2300 SF house.

Also, what temp do you all set your thermostats at in the summer?

Thanks!

Agree with RedNeckRick. You didn't say if the house was one or two story or how many tons it is rated at. Some home builders undersize the A/C unit to save money. You will need a 5-ton unit (one ton for each 500 sq ft) to handle the air flow and keep the unit from working overtime to cool the house down.