Air Conditioner not cooling. Too much or too little freon?

Question

Goodman Manufactoring Company

Model CK24-18

Serial 9807510241

Compressor was replaced 2-3 years ago

Inside coils replaced 1-2 years ago

In all the years I've had the unit (since 1998), it has never cooled the house. House has double pane windows and 8 inches rockwool and 4 inches corning (pink rolls) on top.

Now it's "in the toilet". pipes outside were warm and dry. Temp outside was 98F and inside 85F and air in vent 78F. Next day, pipes outside are 1 1/2 inches of ice. Air still flowing across inside coils. Temp exactly the same. hvac guy comes out and charges with freon. Waited 3 hours. Temp outside 98F, inside 92F, air in vent 77F after running ac 2 hours. Pipes outside (big one) barely cool to touch, small line feel like "air temp".

In early spring, inside coils would ice over about once a week. Air would not flow over coils. Shut it off an hour then turn it on, works. Even then, outside 90, inside 80, in vent 75.

Help

Answer 1

you ever thought of putting a couple of window units in the house instead of driving yourself crazy with this central air thing for the past 10 years?

they are sealed up--they hardly ever leak. ( I never had one leak and i have one thats older than your central air unit and still going strong) if they go kaput the price of a new one is the same as a service call from the repair man..

and if one goes you still have one or 2 more pumping away.

Answer 2

I agree with some of each of the answers. You appear to have a 2-ton unit. In a moderately dry climate, that would be able to cool a home of roughly 1000-1200 square feet. If you add a high humidity to that climate, then you're probably undersized. Your cool suction line is probably normal for the indoor temperature you have, as your suction pressure would be a little higher than normal until you got the house cooled down. A 15 degree split is definitely at the low end of the desired amount of cooling, which tells me that it's either too humid, or too small. Was the indoor unit installed as a package with the condenser? If not, it may be that your indoor fan doesn't provide enough air flow for the tonnage. At 2 tons, you need about 800 cfm of air moving across that coil. If the coil had been installed on an existing furnace, the fan may not have enough capacity to move the proper amount of air, which could cause the unit to freeze. You may well get away with supplementing the air with a window unit or two. I would definitely have a thorough load calculation done before replacing it in the future.

Answer 3

you need to have a Air Conditioner guy come out and look at it.  The freon may be low or there could be something wrong with the wireing on the inside of the house on the main unit.  But check the freon first.

Answer 4

The model number is a CK24 which means the unit is a 2 ton.

In the deep south a good rule of thumb to go by is this: Each bedroom gets a ton. So if you have a 3 bedroom house you need a 3 ton unit. A ton is 12000 BTU's and from that model number I will guess it is a 2 ton. If you have a 2 bedroom house I guess a 2 ton would work. I am also guessing you have a larger house. You need to add another unit for hot hot days.In the long run It would all workout. I would add a 3 ton unit along side that 2 ton unit. Run 2 thermostats. Use one as a back up. Use both on very hot days.

Answer 5

i gotta agree-bad leak. The fact that your coil were icing and then you have nothing denotes a leak. If the tech comes out and just ries topping it off, tell him you want a leak check done. Otherwise he will keep making money on you.

Plus, the 5 lbs of refrigerant in one shot is a little excessive unless your lines are a mile long.

If it is undersized, it has been since it was installed and that sucks for you but the only way to fix it is to replace the whole thing. inside,outside and lines.

Answer 6

you have a 2 ton unit which may be undersized.

since you just had it serviced, call them back and tell them its still acting up. they should recheck for nothing, i would. have them check the temp from the return filter and then check about a foot above the coil on the inside.  you should have 15 low to 20 high temp difference between the two

look over their shoulder to see the temps for yourself bc you re wasting alot of money for cooling costs you re not getting.

if you re freezing up just after they left, you obviously have a leak. it wont be your filter bc they definitely would have checked that. recheck the refrigerant, make sure your suction pressure is in the 75 to 85 range if its in the daylight sun. thats the bigger of the two copper lines. again, look over their shoulder, sounds like they dont know what they re doing or they re just not very reputable.

Answer 7

You have a bad freon leak. I would suspect it's where they brazed the compressor or the inside coils. After someone installs coils, or a compressor they should perform a leak test before they put freon back in the unit.

Answer 8

With the outside condenser operating in 100 degree heat and you are getting a 15 degree drop from the unit, it sounds within range but at the low end. When the outside temp is that high they lose some efficiency. But many factors play in to the temp coming out the vents.

I don't know the tonnage but it might be small for the house.

You might want to add a window unit or two to suppliment it and run it until time for a replacement and get a larger one.

It doesn't sound like the a/c unit is the problem to me.

With it 100 degrees outside for the condenser (is it in the shade?) I have seen some people use a garden hose with a mist fitting to water cool the condenser some and improve efficiency.

Hot ambient temperatures raise the pressure in the whole system making it harder for the compressor to work.

Good Luck.