Why is our air conditioning suddenly worse after a repair?
July 11, 2022 9:11 AM Subscribe
We recently got back from a week's vacation, arriving home at midnight to a dead air conditioner. In July. In Texas. Many tears were shed. We had a recommended repair company come out the next morning, and he fixed it. All was well! Except... not.
The initial cause of the break was the coils freezing over. We'd set the AC to 72 while we were out of town, but it was totally our fault. We didn't replace our filters enough due to one filter being inaccessible. (Who puts an intake 10 feet above the stairs? Where you can't put a ladder?!) We'll be hiring someone to handle that one on a monthly basis moving forward, lesson learned. We also had the capacitor replaced, since it was 3 years old. (Same age as the house)
All pressures are good, no leaks, nothing in the ducting that created an issue.
Part of the fix was also installing a return air sensor on the attic unit/air handler in order to keep the air from getting too cold. (Apparently the water dripping out of the soffits these past two years hasn't been a positive) He seemed surprised there our unit didn't have one, and reassured us that it would prevent it from freezing again. The worker was great, explained exactly what they were doing, was kind, patient, and took our concerns seriously. He explicitly said we could set the AC to 65 without issue. All in all, a positive experience. However.
Ever since the fix, the AC runs! But each day, the house gets warmer. Day 5, and the darn thing won't get below 68 on the first floor, and won't get below a roasty-toasty 78 on the second floor. I have a lot of heat intolerance due to medication and medical issues, so I've been sleeping covered in ice packs on the coach downstairs but this isn't sustainable. I suspect it's the new sensor or the thermostats, but now I'm nervous.
What the heck happened? How do we fix it? I'm not above calling a professional in again, but I need to know if I should call the same company or look for another solution. Any experience or guidance is appreciated, as always.
The initial cause of the break was the coils freezing over. We'd set the AC to 72 while we were out of town, but it was totally our fault. We didn't replace our filters enough due to one filter being inaccessible. (Who puts an intake 10 feet above the stairs? Where you can't put a ladder?!) We'll be hiring someone to handle that one on a monthly basis moving forward, lesson learned. We also had the capacitor replaced, since it was 3 years old. (Same age as the house)
All pressures are good, no leaks, nothing in the ducting that created an issue.
Part of the fix was also installing a return air sensor on the attic unit/air handler in order to keep the air from getting too cold. (Apparently the water dripping out of the soffits these past two years hasn't been a positive) He seemed surprised there our unit didn't have one, and reassured us that it would prevent it from freezing again. The worker was great, explained exactly what they were doing, was kind, patient, and took our concerns seriously. He explicitly said we could set the AC to 65 without issue. All in all, a positive experience. However.
Ever since the fix, the AC runs! But each day, the house gets warmer. Day 5, and the darn thing won't get below 68 on the first floor, and won't get below a roasty-toasty 78 on the second floor. I have a lot of heat intolerance due to medication and medical issues, so I've been sleeping covered in ice packs on the coach downstairs but this isn't sustainable. I suspect it's the new sensor or the thermostats, but now I'm nervous.
What the heck happened? How do we fix it? I'm not above calling a professional in again, but I need to know if I should call the same company or look for another solution. Any experience or guidance is appreciated, as always.
My understanding is that central A/C units are design to compensate for about 15 degrees of heat -- so they can bring 90F down to a comfy 75F, but 105F might be more than it can manage. Did you used to get more relief than you are getting now?
I know that much of Texas is basically en fuego this week, and you have my sympathy! Our A/C is only a few years old and gives us fits every spring, despite us doing everything they tell us.
(Mind you, I am locked in a multi-year battle with the people who installed our A/C, and the state of the art seems to shift every 12 to 18 months. They swear up and down that there is The Truth, but it seems to change with new science or something.)
posted by wenestvedt at 9:28 AM on July 11, 2022 [1 favorite]
I know that much of Texas is basically en fuego this week, and you have my sympathy! Our A/C is only a few years old and gives us fits every spring, despite us doing everything they tell us.
(Mind you, I am locked in a multi-year battle with the people who installed our A/C, and the state of the art seems to shift every 12 to 18 months. They swear up and down that there is The Truth, but it seems to change with new science or something.)
posted by wenestvedt at 9:28 AM on July 11, 2022 [1 favorite]
A/C coils icing over is a sign of low refrigerant. I'd call a different company if you can to check the system again and get a second opinion.
posted by JoeZydeco at 11:27 AM on July 11, 2022 [5 favorites]
posted by JoeZydeco at 11:27 AM on July 11, 2022 [5 favorites]
Mine stopped and I took it apart and cleaned out the leaves, it is working great again. It sounds like you are under refrigerated. When I put in my units I calculated the BTUs needed to cool my place. I bought a little less because I have ceiling fans. ACs create condensation in humid climates that is where the water problems come from. They have drying cycles so you can de-humidify the air inside your house. I learned only recently that AC does not exchange air with the outside, it just exchanges heat via the compressor. Running the AC at 62 while not at home, puts a strain on the system, that is when you should run it at 78° or even 80°.
posted by Oyéah at 2:49 PM on July 11, 2022 [1 favorite]
posted by Oyéah at 2:49 PM on July 11, 2022 [1 favorite]
Best answer: I learned only recently that AC does not exchange air with the outside, it just exchanges heat via the compressor. Running the AC at 62 while not at home, puts a strain on the system, that is when you should run it at 78° or even 80°.
Yes #1 is right, which is why the 15F differential thing mentioned above is incorrect. AC's can cool much lower than 15F, depending on insulation, return air ducts, and size of the machine.
However, #2 has more to do with money (operating costs and system longevity) than with system strain. People being home is more of a 'strain' on the system, considering that each person is 98.7F+ degrees of heat walking around.
I'd agree to get a 2nd company to check the level of refrigerant because everything stated above by the OP seems mis-heard or incomplete.
posted by The_Vegetables at 3:18 PM on July 11, 2022
Yes #1 is right, which is why the 15F differential thing mentioned above is incorrect. AC's can cool much lower than 15F, depending on insulation, return air ducts, and size of the machine.
However, #2 has more to do with money (operating costs and system longevity) than with system strain. People being home is more of a 'strain' on the system, considering that each person is 98.7F+ degrees of heat walking around.
I'd agree to get a 2nd company to check the level of refrigerant because everything stated above by the OP seems mis-heard or incomplete.
posted by The_Vegetables at 3:18 PM on July 11, 2022
Best answer: Call the company back out. It could be something like a brand new "bad" capacitor or whatever.
A friend just had a repair done that worked for some number of hours, then didn't. The company came out and replaced that part again. Same scenario. Third time, they tried a different brand "thingy" and it is now working perfectly. Bad batches of manufactured parts do happen.
Or, it could be some other mysterious thing. But, give the repair company another shot. If they seem dismissive, then consider someone else.
posted by mightshould at 3:19 PM on July 11, 2022
A friend just had a repair done that worked for some number of hours, then didn't. The company came out and replaced that part again. Same scenario. Third time, they tried a different brand "thingy" and it is now working perfectly. Bad batches of manufactured parts do happen.
Or, it could be some other mysterious thing. But, give the repair company another shot. If they seem dismissive, then consider someone else.
posted by mightshould at 3:19 PM on July 11, 2022
The Vegetables: ...the 15F differential thing mentioned above is incorrect
It is? Goddamn A/C company, I hate them so much.
posted by wenestvedt at 10:40 AM on July 13, 2022 [1 favorite]
It is? Goddamn A/C company, I hate them so much.
posted by wenestvedt at 10:40 AM on July 13, 2022 [1 favorite]
It is? Goddamn A/C company, I hate them so much.
Yes, unless they have convinced you that everyone in Arizona/The Valley in California/Texas just deals with the inside of their house being 100F when it's 115F outside. They do not. An A/C can cool 115F to ~65F under normal operating conditions in 24 hours, because the air is recycled and gradually cooled. Again depending on the insulation, tightness, etc. But 15F at 100F would still be borderline unlivable, so that's a bare minimum, not a maximum.
posted by The_Vegetables at 3:13 PM on July 13, 2022 [2 favorites]
Yes, unless they have convinced you that everyone in Arizona/The Valley in California/Texas just deals with the inside of their house being 100F when it's 115F outside. They do not. An A/C can cool 115F to ~65F under normal operating conditions in 24 hours, because the air is recycled and gradually cooled. Again depending on the insulation, tightness, etc. But 15F at 100F would still be borderline unlivable, so that's a bare minimum, not a maximum.
posted by The_Vegetables at 3:13 PM on July 13, 2022 [2 favorites]
Response by poster: Our neighbor came by and took a look for us- The upstairs thermostat had been disconnected while the repairman was working. It looked like it was on, but wasn't connected. Problem solved! The answers were very helpful, though, and I think I know a lot more about AC now. Thanks MeFi!
posted by Torosaurus at 1:48 PM on July 14, 2022 [1 favorite]
posted by Torosaurus at 1:48 PM on July 14, 2022 [1 favorite]
This thread is closed to new comments.
What do you mean by this? Like a leak, or through your secondary drain pipe, which drains outside your house? If water is draining from that pipe, then your primary condensation drain is clogged. The issue there is leaks, not your A/C not working though.
I'm also confused by the 72F thing. If you normally set your AC to 65 then why did setting it to 72 cause a problem?
posted by The_Vegetables at 9:25 AM on July 11, 2022