AC not keeping up - tech says its ok - any ideas?

Sounds like you are f***ed.

Better buy some stock in the electric company.

Cleaned outdoor coils... how? Hope he used chemicals and a water hose.

Twenty degrees is a good temp drop over the evaporator. But is the fan in the furnace at top speed?

What's the humidity like, there? High humidity takes a lot of power to dry the air.

The one time I saw this kind of problem, the folks were smokers. It was a 90 degree humid day, and every time they would step out to smoke, they would hold the door open for several seconds. And let the heat and humidity in.

Try opening ALL the vents, and see if that helps. Makes me wonder if you've restricted the air flow.

Also wondering if there is enough return air ducting?

Please let us know how things work out.

With a garden hose.

I'm not sure. I'd probably have to open up the unit and see what wires from the motor are hooked up. Its pretty noisy when the system kicks on, I'm pretty sure its on the highest speed.

Its been very humid lately.

No smokers here. And the doors have not been opened much in the last few days.

I went over a talked with my neighbor today, and his house was 79 when mine was 75. He said thats just about all they do around here, and that these open floor plan houses run pretty warm.

Return ducting could be an issue, I don't see a whole lot of it. We sleep with the bedroom door open, and when I open that door I can feel a ton of air flowing out of the cracked door. - I just went and looked and only found two returns on the upper levels of the house. One in the hallway between all the bedrooms and main bath, and one in the living room. Cheap construction I guess. My last home had returns in just about every room.

I would pay to have another company do a heat load of the house and see if it, the A/C the right size for your home.

If it is then have them check the duct work to see if it has been installed right.

With a garden hose. CY: I've used a garden hose. Had good results with a pressure washer, but that's a skill to be learned. Som eof the coil cleaing chemicals sure help loosen the dirt.

I'm not sure. I'd probably have to open up the unit and see what wires from the motor are hooked up. Its pretty noisy when the system kicks on, I'm pretty sure its on the highest speed. CY: A slower speed can give you a higher temp drop. But that doesn't mean you are moving heat.

Its been very humid lately.

No smokers here. And the doors have not been opened much in the last few days.

I went over a talked with my neighbor today, and his house was 79 when mine was 75. He said thats just about all they do around here, and that these open floor plan houses run pretty warm. CY: Hmm. Maybe needs better window shades, or more air flow. Or some more cooling, like a window unit upstairs.

Return ducting could be an issue, I don't see a whole lot of it. We sleep with the bedroom door open, and when I open that door I can feel a ton of air flowing out of the cracked door. - I just went and looked and only found two returns on the upper levels of the house. One in the hallway between all the bedrooms and main bath, and one in the living room. Cheap construction I guess. My last home had returns in just about every room. CY: Very possible. Might be depending on people leaving doors open. I'm starting to think that poor return air is a serious problem in a lot of cases.

snipped-for-privacy@yahoo.com wrote in news:1153608072.595587.231370 @s13g2000cwa.googlegroups.com:

I've checked the air coming

Then the AC is doing it's job. It sounds like an airflow issue. Like someone said, could be a return air problem.

I missed there area of the country you live in. If the system is designed for 90° out side temp and you have 104° outside. This will have a great difference in system operation. You gaining more heat than removing.

Pardon the obvious, but add 10 - 12 inches of insulation in the attic.

~135m2

~8.8kW Now, 8800/135 = 65w/m2. Normal design for domestic would be

He wasted your money. He didn't pick the unit is too small. Another professional ripping of the public.

It will be a killer. You need a bigger unit or zoning to reduce the load. Best of luck.

Seems like one of the few people on this site that have any idea of what they're saying. Heat load is required, however a rule of thumb (130-140 w/m2) can be applied. In domestic installs I've witnessed, the ducting is usually installed poorly, BUT, capacity is important. 1st things 1st. The unit needs to cater for the correct load. Either reduce the load or increase the unit size.

PJ ;-) posted for all of us... I don't top post - see either inline or at bottom.

Huh? Ya got two? I have been reading this group for years and even I have picked up: rule of thumb = hack.

Read the first sentence of my post dated Tues, Jul 25 2006 4:18 pm in relation to Moe. Take the hint !! Prove my figures wrong !

PJ ;-) posted for all of us... I don't top post - see either inline or at bottom.=20

YOU are WRONG

--=20 Tekkie

You just described my situation EXACTLY. Exactly the same kind of temperature swings, etc.

Outdoor unit is a TempStar 2.5 ton 12 seer.

Indoor unit is a Goodman GMP075-3 (only one notch up from the cheapest and least powerful unit they made).

I live in a condo which I learned are usually made from the absolute cheapest materials available to keep costs down.

I've had techs as well say the same thing, "it's running fine." Finally I was advised that the system just isn't powerful enough.

I'm having someone come out to spec me out a new ac/air handler that will do the f****ng job.

snipped-for-privacy@yahoo.com wrote:

You need to have the tech carryout a heat load. Anything less than

I have seen people on this site bitchin' about unit performance and it happens they have something like 50w/m2. No bloody wonder it doesn't work. Put a two cylinder bike motor in an F350. It will perform like s*it. You need correct capacity for the job.

Before you replace equipment, please try to find an AC service guy who knows how ot clean coils. I've seen several times that dirty coils behave like too little cooling. A cleaning may restore the cooling.

Almost None of the 500 homes in my neighborhood have room returns. Only those that were added by a few homeowners after the fact.

The main 20x25 return is in the common area next to the furnace and all the interior doors have a large gap at the bottom for return air.

But my doors are seldom closed anyway so no big deal to me and in 22 years, I have no complaints about no returns.

Bottom link provides some info concerning duct systems. - udarrell