Amana HVAC question
First off I'm a layperson at this so bare with me. I recently bought an Amana heat pump and air handler to replace a 17-year-old Goodman. PROBLEM: It runs FOREVER!!! I live in Las Vegas and this is the first hot whether the unit has experienced and come 95-100 degrees, the thing won't shut off. It was 106 the other day and it could not cool the house down below 81-82 degrees and ran from 1pm until I had enough and shut it off at 8pm. Now, we here in Vegas know that at those temps from 1pm to 4pm your AC is gonna run without shutting off, but not until 8pm. I've had the contractor come out once already and the tech said that the refrigerant was a little low so he "topped it off" (my words, not his). The old unit didn't run nearly as long or as often as the new one even at lower outside temps.
The output at the registers seems too high: 65 degrees @ 95 outside, 71-72 degrees over 100. I'm not asking this thing to make it so cold I can hang meat in the kitchen. Therm is set at 79-80 degrees. I inspected the HP and (I'm just trying to compare it to something) the supply line is cool to the touch, were as my neighbors are COLD. The new unit is a 5 ton and the old one was 4 ton. Should cool the house even better, no? The old unit worked far better than the new.
Everything, to my limited observation, is telling me there is a problem, but I have no way to prove or disprove myself, so your input would be greatly appreciated! Because as it stands right now, I think it's broke and the technician is going have a bad day if I don't like what I hear from him. If I'm gonna be "that guy" to the tech, I want to make sure I'm a LITTLE educated on the subject matter...
Amana: ASZ-140601AC HP and AEPF-426016BB AH.
1760 sq ft upstairs condo with cathedral ceilings. Tile roof, stucco walls.
Duct work is in the attic and everything is insulated with short runs from the AH to most registers. HP is in a constantly shaded area.
Thanks in advance...
take a temperature reading at your return grill
then take a reading at the supply grills
you should have at least 16 degree difference
if not there may be a problem
Could have a leak in the return duct. Pulling in hot attic air can cause what you describe.(not saying that is definitely the problem)
Did the tech go into the attic and check anything.
Its possible, that if you have electric aux heat, its miswired and coming on.
When teh tech checks the charge.
He should be checking that the air handler is moving the right volume of air, and the indoor wet bulb and dry bulb temp, the super heat and sub cooling at the outdoor unit.
And increasing size by one ton doesn't mean it should cool better. Many times, it does worse.
I also think there may be leak return at attic because the supply air temp goes up with the OAT. Normally it only changes with the room or return temp.
My A/C puts out colder air when its 80 outside then when its 95 outside, at the same indoor temp.
If its not cooling your house then theres a problem. Period. Maybe the strips are on like Beenthere said.
Why the upsize?
I run into that alot here, people have this mentality that they want a larger unit even though the last one worked fine. I have seen many hvac contracters here upsize when it isnt necessary. I was in an old 50's block style house a couple of years back that was only 1,000 sq ft, and she had a 4 ton unit sitting on the roof, I couldnt believe it. Granted, we dont have the humidity issues, and we do get alot of heat but, you gotta draw the line somewhere! My neighbor had her rtu replaced by a reputable dealer 3 years ago and they upsized hers from a 4 to a 5 ton. Her old one worked just fine but they convinced her that going bigger would run less and use less energy! I didnt know her at the time or I would have convinced her otherwise.
AIRMECH: In the hot periods the return is 81ish and supply 71ish.
BEENTHERE: No he did not go into the attic. I too, wondered about the volume of air and your AUX heat is an interesting thought. I'll look into that.
VIB: I started taking readings and it definitely moves with the OAT and not so much with the inside air temp
AR_HVAC: No conscious choice on my part. I chose only the brand, the rest was selected by the contractor.
I'm still wondering about the refrigerant output line from the HP. Why is it not as cold as the neighbors??
Thanks again for the help, you guys a great...
Thanks SAMMY...What would be your recommendation?
If your drawing 135* attic air into teh return, your line vapor line won't be cold.
He got this: 65 degrees @ 95 outside, 71-72 degrees over 100. I dont think you got 15 colder air. Especially after ac runs for a while, there shouldnt be a big difference at supply air when the room temp and RH the same.
Originally Posted by beenthere
BEEN: By the "return" you mean the air duct that supplies the air from the house to the AH, right? Vapor line? Is that the cold refrigerant line from the HP?
As the OD temp increases, the capacity of the A/C decreases, so at same indoor conditions, the discharge temp would be warmer at higher OD temps.
An A/C with 50,000 BTU sensible capacity at 95* may only have 42,000 BTU sensible at 105*.