Do you mean the screen you pull out and vacuum or wash? It’s been vacuumed. The loaner has no filter in it.
There’s another question we haven’t asked the OP. What kind of space do you live in.
If you live on the upper floors of an old-fashioned red brick masonry building, you’re basically living in a pizza oven. The bricks may take a long time to heat up, but they’ll also take a long time to cool down, even if the outside air is relatively cool.
Are your walls warm to the touch? Do they feel warmer than, let’s say, a piece of wood furniture?
I understand today that the warranty was only on the compressor. Apparently if it’s not that then they might just say that there is nothing they can find and you are out of luck. It seems like a lot of trouble to try to nail down whats wrong with the unit now.
The point is that AC compressors are either on or off. Your unit is either cooling full blast or it’s off. AC set to 64 degrees blows the coldest air it can until the thermostat hits 64 degrees, and then it shuts off.
When the same unit is set to 84 degrees, it blows the coldest air it can—the same temperature as in the first scenario—until the thermostat hits 84 degrees, and then it shuts off.
In the first case, the compressor runs longer than in the second case, but it doesn’t run “harder.”
Because of this, the temperature of the air blown by the AC unit is the same whether you set it’s thermostat to 86 degrees F or 68 degrees F. The fan in your AC unit can be throttled, but the compressor can’t. It just runs full-speed until it hits the desired temperature.
The technical term for this—approximating a continuously variable output by cycling full power on/off over time—is “pulse width modulation,” or PWM. It’s incredibly common in devices that aren’t easily throttled, such as air conditioners and most (not all) microwave ovens.
You seem to think that you’re incapable of measuring the temperature of the air blown by your AC unit, though I’m not sure why. Even a mercury thermometer would work fine. HVAC pros use infrared thermometers to measure temperatures instantly from a few feet away. Those IR thermometers are pretty cheap these days—$25 or less—and they’re certainly cheaper than buying a new AC unit to replace one that’s under warranty.
If you bought or borrowed such a thermometer, you may well find yourself in a strong position, asking the warranty people something like “if my unit is working fine, why is it blowing air that’s 15 degrees warmer than your loaner unit?”
I mean, you don’t have to measure the output temperature, but let’s not pretend that it’s difficult or pointless to do so.
If the warranty is only on the compressor and the compressor isn’t broken, that’s probably the end of that. Now, assuming they didn’t just turn it on, hear the compressor kick on and tell you it’s fine, they would need to hook up (pressure) gauges to fully diagnose it. If the unit is low on refrigerant, they would have caught it at that point and even if it’s not covered, hopefully they’d let you know. In fact, I’d hope they let you know what the problem is, assuming there’s a problem, even if they don’t fix it.
The compressor isn’t something you can fix yourself. In fact, it’s really not even worth fixing. Low refrigerant, due to a leak somewhere, may be worth fixing, but again, not something for the homegamer. That leaves only a few things, the motor, fan blades, electronics, buttons etc all sound like they’re working fine. The last thing that leaves is the unit being dirty. You said you cleaned the filter. Pull off the front cover and look (but don’t touch, they’re sharp and bend easily) at the coils/fins. If they’re packed with dust and dirt, they need to be cleaned. On the back of the unit is another set of coils. Same thing, if they’re dirty, clean them. Both sides draw air from the side you’re looking at into the unit, so if there’s dirt to see, you’ll see it right on the surface.
If those are dirty to the point that they’re restricting airflow, it’s part of the problem, if not the entire problem.
Having said all that, I still believe your AC was simply not up to the task of cooling your apartment in 90+ heat. If it worked right before the heat wave, I’ll bet it’s fine when you have it back and the outside temp is more moderate. In that case, either re-install it and keep using it or get a new one and use that as a backup that you can install into another window when you know there’s a heatwave coming.
The outside condenser coil is usually the opposite. The fan is blowing air out through the coil, and sucking air in from the vents at the sides and the top. That helps keep the compressor cool and also allows the fan blades to sling water over the condenser coil. That makes the condenser very hard to clean though, because a strong enough stream of water shot from the front/outside to dislodge the gunk on the inside would also bend the fins. Plus since the pipes in the coil are staggered, you can’t really get a clean shot through from front to back anyway. I’ve had to take apart window A/C units partially in order to properly clean the condenser coil since nothing else would work. Even with the case off and the fan’s shroud removed it can still be very difficult to get in there to do a decent job.
My apartment is a very similar size and it’s a 100 year old brick masonry building. I don’t have any double-pane windows though, and I’m on the top floor, but there is blown-in fiberglass insulation in the attic. My two window A/C units total 15,500 BTU and they can only just get the job done (by which I mean cool to 74 degrees or so) when it’s 90 degrees outside. So it sounds like the OP’s apartment is a bit better insulated, and if the 12,000 BTU loaner unit works fine, then yeah the original one is probably toast. If there’s nothing wrong with the compressor, I would guess low refrigerant or blocked up coils, or both.
Just tape a little temp reader on the vent? Where do you put one to get the input room air?
At this point it’s too much trouble to get it back and test. It’s out, a loaner is in. A new one is in the cards, and the haul away is a factor. If I try to test the machine it will be logistically a problem.
If I measure it and the temp is too high they will say that there were other probems such as mold or dirt that are my problem. They most certainly will not fix anything if it’s not the compressor.
Dude, the loaner is working fine at 12k BTU. The problem unit is 14k.
I was told they tested it for 8 hours.
The input air is the outside air around the unit (if it’s set to “fresh air”) or the air inside the room (if it’s set to “recirculating,” “max cool,” or some phrase like that.)
You don’t even need one of those big, old-timey bulb thermometers. I have a thermometer in my refrigerator that reads up to 80 degrees. That will tell you if there’s colder air coming out of the unit than the air inside the room.
Just measure the room temp? I do that anyway. So take the room temp and get a reading off the cool vent of the machine, and those make the delta?
I’m using these little tiny black box thermometers with a humidity reading.
No.
Measure the temperature at the AC intake vent and measure it again at the output vent. The difference in those two temperatures is the delta.
You seem convinced that the situation is entirely hopeless. You completely dismissed Joey P’s recent post, which was chock-full of helpful, concrete suggestions. Even if my suggestions weren’t helpful, I certainly intended them to be.
Maybe I’ve misunderstood the premise of the thread. Are you looking for help getting your air conditioner fixed? Or are you more interested in an audience for your complaints?
I always post to find out more info than I started with and to move forward. What are you looking for? In this case it’s about when your A/C is underperforming, and out for repair. I think you are getting a little carried away with policing the mission.
Joey said that he thinks the machine wasn’t up to it, and was not compromised. I disagree. Do you want to know more about it? OK: I live here and I don’t think so. The loaner works. What am I supposed to say?
Sometimes the solution is not to fix the machine. So you are offering a false dichotomy/choice in your last sentence. Can you read the posts before asking me to make everything clearer?
You’re asking a lot from a 14,000 BTU unit. At some point it’s not going to keep multiple rooms cool. I don’t care how many transoms and fans you have. There is a temperature at which it cannot keep up and that is dependent on how much heat is entering the apartment.
Unless you are living in an air tight room similar to a refrigerator you are eventually going to reach a point the air conditioner can’t keep up. Whether that temperature is 96 is unknown because we can’t calculate thermal transfer over the internet.
I can tell you that when my central air went down it was tough for a 5200 btu window unit to cool a small bedroom when it went over 95 deg.
If you have a 12,000 btu unit that works better in 96 degree heat than the 14,000 btu unit than all things being equal you’re 2,000 btu short of advertised performance. But that is all things equal. 96 degrees vs 96 degrees.
Finally, your A/C doesn’t care about your discomfort. Consider buying a smaller unit for the bedroom to give your main unit a break and also as an emergency backup.
So just to be clear about something, how long did the heat wave last? Was your old unit only not working during the heat wave, or even after the temperatures returned to normal?
And with the 12k BTU loaner, did you only start using that after the heat wave already passed?
Or has the heat wave persisted through this whole process, with the 12k BTU unit being able to handle cooling just fine while your old unit couldn’t? If that’s the case and you don’t want to clean it and the manufacturer doesn’t give a damn, then yeah, what choice do you have but to replace it? People here were just trying to offer troubleshooting tips so you wouldn’t have to buy a whole new one, or at least give you the tools to prove to the manufacturer that something isn’t working right, despite their tests, but sounds like they wouldn’t care anyway.
Well my working assumption, derived from the bolded part of your text, is that my unit is not working efficiently, and must be in a compromised state vs prior usage. ( and as vs a lower powered unit) I don’t follow the rest of that point. advertised, equal…Can you explain?
I am not getting a unit for the bedroom, I don’t need one. It’s hard to get or know that over the internet and all, but can you trust me on that? I don’t want one. I don’t need one, and I would have a hard time logistically to make one happen.
Also my transom is the best idea I ever had. You should try it. I don’t care how many transoms you hear described over the internet, there is a time when you can’t imagine what’s happening in someone elses home without seeing it.
Yes. Yes. I have reality tested this, using due dilligence, and the loaner works and the broken one doesn’t. Believe me. Why that is I don’t know but it may be too much hassle to track it all down.
The question I have right now is what do they think it was and why didn’t they give a diagnosis instead of just saying “No” But I do believe I need to get a new unit.
Interesting. Every reefer system I’ve ever worked on draws air through the coil and then over the compressor. Going in the opposite direction appears to be unique to window ACs. A bit of googing shows some go one way, some the other, both with their own advantages and disadvantages that are well outside the scope of this thread.
And for cleaning, yes, it’s very easy to bend the fins, I’ve done that once or twice over the years. However, if you can get right up to the unit, a good cone/fan spray from a hose does a pretty good job of getting most of the gunk out, it just takes a while. There’s also dozens of cleaners (including a foaming one non-pro can pick up at Home Depot) that may or may not help the process. It’s also helpful that the coils aren’t that thick. Cleaning out coils that are only and inch or two thick is a lot easier than cleaning coils that are 6 inches deep. In all likely hood a powerful, but gentle spray from a hose will clean them very well.
Is it still 95+ degrees out or has it cooled off?
Yes, I said it’s very possible it’s not up to the task of cooling off an entire apartment when it’s 95 degrees out. I also made quite a few suggestions for things you could try as well as other possibilities.
Also, you mentioned it would be a problem, logistically to retest the unit. If you’re planning to get a new one, there’s no point in reinstalling this one just to test it, but if you’re curious, there’s no reason why you can’t just set it next to an outlet and plug it in. Just make sure that if you’re indoors, you turn it off before the evap coil starts to form condensation or you’ll have to deal with the water.
If the compressor is good, it could be a problem with the thermostat or a temperature sensor. I had that problem with a fridge once.
Drad Dog mentioned that it was running all day and all night, so it’s not likely a problem with the t-stat, unless it’s set so the fan stays running and the compressor shuts off and he didn’t notice it. But if the warranty place ran it for 8 hours, I’d hope they would have noticed that.