In April we replaced our 15 year old AC condenser. It started needing a little freon a few years back but a lot more last year. That stuff's expensive. Our local dealer who's been in business here for 40 years who installed the old one and serviced it annually. recommended replacing it. We said ok and he Installed a new Guardian 5 ton condenser which on paper is supposed to be more than enough for a two story 2200 sq ft house,

Problem is that it doesn't cool as well as the old one and after it's run a while makes a low metallic whine. It's noticeably warmer in the house, three or four degrees higher and on hot days it will run from noon till well after midnight. Can't wait to see the June electric bill.

I've had their service techs out here three times. They ran some kind of tests and both times two different techs said it was running hot. This was in the morning before the day started warming up. He, the dealer, then had them check the dampers, filter and some other stuff. When I asked him why he checked that stuff since everything seemed to work ok with the old unit I didn't get an answer. He said he'd get back to me. So far, two weeks, nothing

Hate to go to court over $3400 but if a new 5 ton unit won't cool the house as well as the 15 year old one it replaced that was using freon I'd say we've got a defective condenser. Is Guardian usually considered a good condenser?

HVAC guys are like car mechanics, if you find an honest one, become his friend.

What was the tonnage on the old system ?

Did they change just the ouside unit or did they change the A coil (on top of the furnace) and the outside until.

Your 15 yr. old condensing unit was R-22, the new replacement unit was R-410a, the indoor air handler was set up for the R-22 refrigerant, so there must be more to the story, did they change the Txv or indoor coil orifice for the new type refrigerant? If so, did they adjust the superheat for the Txv, or charge specific for the orifice?

Plus the blower motor needs to be rated for the condenser.

I don't know much about HVAC, but I would send the dealer a written demand letter specifying your expectations for the performance of the unit before I would expend the effort and expense on a court filing. I would cc the manufacturer of the new unit on the letter as well. You can also try calling your State Attorney General's office. Often they can put pressure on a business to perform work in a satisfactory manner.

a 5 ton is a pretty massive unit, I think its the largest you can get as a single unit. I guess yours is probably all above grade. I normally run 3 tons units for that size but half the square footage is basement. I do have a house that is 2400 sq feet on a 2.5 ton. but again half the house is basement. HVAC guys can be dishonest. their favorite thing to do is just replace everything. cracked heat exchanger is a favorite excuse. The legitimate one is the old system is running r22, in that case if the problem is major, yeah it probably needs replaced.

parts can be hard to get right now. and like someone said, find a good AC guy and keep him.

Thanks to all for the info. Am I right that a 5 ton unit should be enough if installed right?

Spotshooter They replaced the old outside unit/ condenser with the new one. The furnace is in the attic and they did not go up there.

vferguson3006 the # on the receipt is R407 C. They did not change the Txv/indoor coil or charge specific for the orifice to my knowledge.

Heeler The blower motor appears to be in the condenser housing.

atomchaser Agreed on avoiding court. Letter to owner first. Looks like I've got some good questions to ask.

He needs to replace the inside unit.

Not sure what part of the country you are in, but a 5 ton unit for a 2200 square foot house seems like an awful large system to me. As and electrician we used rule of thumb for AC on commercial buildings around here at 2.5 tons per thousand square feet. Half of that for residential buildings....

The switch to the new refrigerant will make a difference, but not that much difference. Your house should be ice cold with a unit that large if everything is installed correctly and you're moving enough air to circulate it properly. IMO, the heating/cooling contractor screwed up and he's trying to figure out how to fix it without too much money out of pocket....

I think the unit is oversized to begin with and the inside unit should have been replaced at the same time.

I'd always heard 500 sqft/ton of refrigeration for our area as a basis to start discussion. Quick googling to verify this showed 400-600 sqft/ton of refrigeration. This is all just for starting discussion. Lots more stuff would go into that to properly size the system. Windows, doors, insulation, ceiling heights, climate zone, etc.

500sqft/ton*5 ton unit=2500 sqft house

400sqft/ton*5 ton unit=2000 sqft house

600 sqft/ton*5 ton unit=3000 sqft house

Too big of a unit and the temperature will cool down but it won't run long enough to condense the moisture to the coil and the house will stay humid and feel warmer than it actually is.

Too small of a unit and the unit will never reach setpoint without running forever.

My RUDD ac/electric unit is over 20 years old and I know it won't last forever. The only problem I've had with it so far was the outside fan motor quit about 5 years ago (I replaced it). I also figured out that the return air vent was way too small and enlarged it to the proper size (made a big difference in my electric bill). After paying over $1900 ($770 labor) to get the AC fixed in my 2005 Dodge diesel (needed a new compressor, evaporator, condenser, electric radiator fan and some hoses) I decided I'm going to buy all the necessary tools and start doing all my own air conditioning repair. I was an electrician/electronic technician for over 20 years and have been a shade tree mechanic since I was 16.

Sounds like bad juju all around.