Central Air won't cool

[jacksnodgrass]

I need help figuring out what is wrong with my A/C system.
A $75 service call didn't help...

My Central A/C is about 5 years old.
My air-ducts were replaced about 3 years ago.
The outside compressor is free of grass / dirt and appears to be operational.
The air comming out of the vents is cooler than the
air inside the house.
The inside air mover is running, realtivly dust free.
The freeon pipes are cold / frosty.
My filters are changed every 3-4 weeks. The current
filter is clean.
I live in texas and it's hot. It's not hotter than it
has been in the past... it's a normal texas summer.

Recently, my A/C unit has not been able to cool my
house. I set it on 77 and it stays on 24/7 and the
temperature at the thermostat reads 80 to 85. Even at
night when the outside temp is 70, the house is
hot and the A/C does not do a good job of cooling.

The A/C guy came out and charge me $75 and told me
that the A/C is fine and that my attic is just too
hot. It is true that my attic is hot, but it's always
been hot in the past and the AC has been able to get
the inside temp to 74 when needed. He also suggested
that our windows were no very well insulated....
again... true but this hasn't change in the 20 years
that they have been in the house... recently, the AC
has stopped being able to cool the house.

The A/C guy did not measure the temp comming out of the
vents.. he just put his hand up there, felt the air coming
out and said that it felt fine to him. How cold shoud
the temperature coming out of the vents be?

Does anyone have any suggestions?

jack

[comfortdoc]

Originally posted by jacksnodgrass
The freeon pipes are cold / frosty.


What do you mean by frosty?

[dmitch]

If you are saying your line set is frosty as in seeing icing or light frost you need to call them back or someone else

[RoBoTeq]

While the amount of information you gave is appreciated and it is obvious that you are simply frustrated with the situation, there is not much that we can actually go on to determine the function of your system.

Your best bet is to get someone else to look over your system. Require whoever you hire to provide refrigerant pressures and temperatures along with outdoor and return air temperatures, amp draw of outdoor unit and any other pertinent information that a decent technician will use to troubleshoot.

The temperature of the air at the vents is virtually useless by itself and means very little to us. You need to have a professional evaluation of your system to find out what is happening and what needs to be done.

While the heat may not be any worse then other years, if the humidity is higher it can greatly affect the function of the cooling system.

[rickboggs]

Frosty... not good

Nothing to do with frosty... Janitrol, Goodman, and GMC all had fan switchs that fail appling volage to one heat strip. That's 17000 btu's of heat.

[jacksnodgrass]

... frosty.... I can send a pic...

I don't really know what is what... I'll just describe
it as best I can... I opened up the central air stack.
Up top there is a blower. It sucks are up from the bottom.
The air is sucked up past some sort of coils... I think
that's an evaporator or air exchanger or something like
that. The there is an exposed copper tube that connects
to that coil. This goes out to the Compressor on the
outside of the house. There is a little ice build up
on the copper tubing that connects to the coil.. not a
lot... just looks like there is some condensation and
it's cold enough to freeze up.

The A/C guy didn't look at any of the A/C parts....
I wasn't here when he did his service call. ;(

jack

[hillbilly tech]

If ya spent 75 bucks and didnt get anything done id call someone else,if the prob is not corrected when i work on a unit there is no charge,unless it is explained to them before the work is done and this has to be tried to see what we have.

[xersw]

we need pressures sounds like you may need saome redfrigerant,there should not be ice on pipes,cold as a beer can not ice.

[HeyBob]

Originally posted by RoBoTeq
While the amount of information you gave is appreciated and it is obvious that you are simply frustrated with the situation, there is not much that we can actually go on to determine the function of your system.

Your best bet is to get someone else to look over your system. Require whoever you hire to provide refrigerant pressures and temperatures along with outdoor and return air temperatures, amp draw of outdoor unit and any other pertinent information that a decent technician will use to troubleshoot.

The temperature of the air at the vents is virtually useless by itself and means very little to us. You need to have a professional evaluation of your system to find out what is happening and what needs to be done.

While the heat may not be any worse then other years, if the humidity is higher it can greatly affect the function of the cooling system.


That is the best advice this guy got all day long! Jack, follow Robo's advice and call another company.

[t-total]

how much insulation do have in attic. if you dont have atleat 6-8 r-30 insulation and power vent. these 100deg(i live in south arkansas)day will make electric co investor alot of money do math spend money saving alot more

[pstu]

I second Robo's opinion, although he is a pro and I am a homeowner. The things that have remained the same for years, like windows, attic, insulation etc. would not normally explain why your AC performs less well than last year. I live in S.Texas (if you get down to 70 overnite, you probably live in the northern part) and I do not *think* the weather is more severe than last year. I do recall last year we were seeing 100+ degrees officially before July 4, we have not reached near that this year.

Much as you hate to say goodbye to $75, you probably need a $100 guy to check over your system WITH TOOLS, and make some measurements so he can give you a written report of what he has found. The pros have suggested the numbers you want to walk away with, they know far better than I. You might ask to see a sample of the report before you commit, but you need a guy with good analytical skills. Someone with the National Comfort Institute would no doubt have the tools and skills to understand your problem. Probably not the guy you might pick at random from the phone book.

Upsizing your AC is tricky, it probably needs to come with upsizing (sometimes replacing) your prior duct system. It is done often but IMO should be a last resort because AC systems are seldom undersized in the first place. Duct systems on the other hand are often undersized in the first place, and cannot handle the extra airflow a bigger AC requires.

Best of luck -- Pstu

[man from trane]

There should not be any frost anywhere in the system. The air coming out of the unit should be about 17-20 degrees colder than the air entering the unit, which is theoretically the temp inside your home. With the temps you gave I'd like to see 60-67 degree air being supplied from the vents. The tech they sent out sounds green. He should have called for help. I would call them back and express your disatisfaction and make them send a real tech at no charge. If I had to take a guess I would say the system is low on charge, but would need more info to determine. The frost is the main clue; lack of refrigerant or low airflow, most likely. If the frost is on the small line only that is definitely a low-charge indication. Try defrosting it in the meantime by shutting of the a/c and letting only the fan run for 2-3 hours. If you start seeing a lot of water coming out of the drain line after an hour or so, it was frozen up and should cool better after the ice melts from the coil. But it should not freeze up in the first place if everything is normal.

[Edited by man from trane on 07-17-2006 at 02:02 AM]

[curiousgirl]

Im in north Texas and the last few days it has been HOT, 104 today with high humidity. In my home the temp entering the system is 75-78 and the temp coming out of the vents is 56-58. During the heat of the day it will run 2-3 hours straight then shut off for maybe 15 minutes then back on for 2-3 hours. And no frost/ice anywhere.

So yeah you need to call someone qualified out to go over your system.