Too hot in nyc

August 5, 2006 8:19 PM

Why do air-conditioners only last a few years?

This has happened twice already. I bought an air-conditioner (for between 200 and 250 bucks), about 5000 btu's or slightly higher, for an average small dorm room. Each time I bought one, it has not lasted more than 3 years. Each year it is less effective than the previous year, and after the third year, it doesnt even work as a de-humidifier (previously, even if its cooling ability was diminished, it would still sort of dehumidify the air in the room).
Also I believe these are all non-freon airconditioners (didnt they outlaw freon recently) so I dont think i'm supposed to fill the freon or anything.
And yes, I've cleaned the air filter at the beginning of each summer.

So why do air conditioners only last about three years? Isnt it basically the same compressor mechanism that exists in fridges? Fridges, after all, last 20 years or more, a lot longer than three years anyway.

Is there really any difference in buying a 500 dollar air conditioner (in terms of how long it lasts)?

posted by jak68 to home & garden (18 comments total)

What you have is three shoddy air conditioners with slow leaks in the refrigerant lines.

Isnt it basically the same compressor mechanism that exists in fridges?

Not exactly. For one thing, your fridge is much smaller and the system is designed to cool an insulated space. So it's working much less harder than a household AC unit.

Is there really any difference in buying a 500 dollar air conditioner (in terms of how long it lasts)?

If you buy something bigger AND more expensive, it'll be better AND not working as hard as a small one that's running constantly. This is one of those "buy more throw-weight than you think you need" kind of situations.
posted by frogan at 8:46 PM on August 5, 2006

Also, make sure the cooling vanes aren't getting crushed and are properly vented. That's pretty common, and seriously degrades performance.
posted by frogan at 8:46 PM on August 5, 2006

If you buy something bigger AND more expensive

Interesting. I've always assumed that airconditioners are airconditioners. Maybe next time around I'll spend a bit more. I cant put anything much bigger at my current place though, because the apartment fuse already blows from time to time (my room is very electronified!).
posted by jak68 at 8:52 PM on August 5, 2006

What you have is three shoddy air conditioners with slow leaks in the refrigerant lines.

what is a refridgerant line? ;) And what is it leaking?
posted by jak68 at 8:54 PM on August 5, 2006

Window air conditioners suffer from two environmental problems themselves:

1) They don't always get the voltage or current on which they were designed to run. Operating on low voltage can cause their compressor and fan motors to run hot, and lead to premature failure of the compressor.

2) The window mounting of many air conditioners tends to be mechanically bad for the units, leading to buildup of water in the units, or creating high levels of mechanical vibration, which wear rubber compressor mounts prematurely, and cause compressor/coil leaks.

Window air conditioners can be repaired, if you can take them to the proper shops. At the low end of the scale, the costs of repair tend to equal the costs of acquisition.
posted by paulsc at 9:02 PM on August 5, 2006

Freon (R-12) has been banned for at least ten years. Everything made in the last 15 or so years uses R-134a as the refrigderant. R-134a has slightly different properties as R-12 (and isn't quite as good at cooling) but it is close enough that you can consider them more or less the same general thing.

These systems work at high pressures, and ideally form a sealed system. However leaks will cause the refrigderant to esacape as it is a gas at room temperature. As more and more leaks the effectiveness of the system goes down.

Because of the nature of these systems they are not meant to be user servicable at all. In fact the EPA requires that any professional working on them receive training and certification -- at least in the case of automotive A/C systems. To properly diagnose and repair such a system requires a handful of gauges, vacuum pumps, tanks, etc.

I agree that you must be buying some really shoddily made products if they are failing that often. However, if the cause of the failure really is just a matter of a leaky system, then you should be able to find someone that can come to your location, repair the leak, and recharge your R-134a for less than the cost of a new unit. However, if there is actual damage beyond just a leak (such as a pump that is failing, or bent vanes, etc.) then just a simple recharge will not do much and you're better off getting a new one.
posted by Rhomboid at 9:12 PM on August 5, 2006 [1 favorite]

Not to ask a really stupid question, but it wasn't addressed in the question or any previous answers: you're cleaning out the filters every once in a while, right? You should be able to just open the front door, remove the screen, run it under water or wipe it with a paper towel, and replace.
posted by whatzit at 9:18 PM on August 5, 2006

Gad. I can read. never mind. But you might want to do it more than once a year, still. How did I miss that twice?
posted by whatzit at 9:19 PM on August 5, 2006

I bought my first window unit 22 years ago, and just gave it away last summer, still running fine. Both are 5,000 btu, but I got a new one because the old one was a power pig.

The new one doesn't have the same bone-chilling cold of the old one (different freon?), but it's good enough for a 12x12 bedroom.

But I don't know where you are paying $200-250. I got this one for $69 at the supermarket, and picked a second one up for $39 at christmas. You never know when you'll have guests...
posted by Marky at 10:21 PM on August 5, 2006

Your air-conditioner should suit your room. Are you sure you haven't been moving into larger spaces and still relying on the small unit to do the same work?

buy something bigger

Actually a bigger ac isn't always the best option - especially for a small space. A bigger unit will cycle more (wear on the compressor, etc) and use more electricity.

"I should get an air conditioner with the most Btus possible, right?" NO. Believe it or not, it is possible for an air conditioner to be too powerful (even on its lowest setting). Furthermore, the more Btus an a/c has, the more it costs. Btus are the best indicator of what air conditioner you should buy, so carefully figure out what you're looking for. The smaller the room, the fewer Btus needed.

More here.
posted by wfrgms at 10:41 PM on August 5, 2006

MeFites answer a fellow New Yorker's question about ACs.
posted by NYCinephile at 1:55 AM on August 6, 2006

Craigslist is your friend for A/C units. I just sold a 15,000 BTU window unit for $60 and that seemed to be about the going rate.
posted by stupidsexyFlanders at 3:41 AM on August 6, 2006

I have, on my back porch, a 6000BTU window unit that is *well* over 30 years old, and was working just fine the last time we turned it on. Admittedly, that was about 4 years ago, but I have no particular reason to think it will have died yet.

I don't think we ever had to have it recharged.
posted by baylink at 1:23 PM on August 6, 2006

thanks for all the feedback. It sounds like quality varies a lot based on the model.

and henceforth I guess I'll try my luck on craigslist!
posted by jak68 at 10:08 PM on August 6, 2006

One other note: it's often a good idea to buy an A/C unit that's *a little* bigger than you need... but no more than 25-33% (I think the rule of thumb is).

If you over-cool *too* much, you'll have other problems.
posted by baylink at 6:38 PM on August 8, 2006

Do you have cottonwood trees in the neighbourhood? The fluff they give off will plug up the condensor coils in short order causing at first reduced capacity and eventually a burned out compressor from excess heat.

When I was in the appliance business I had steady spring work cleaning the thru the wall A/C units in motels. To do a good job take the unit down to your U-Do car wash and remove the outer cover which is usually held on with only a few screws. Then give it a good wash. Let it sit for a day after washing to make sure water has dryed from all electrical bits. If you do it every fall before packing the unit away you'll be good to go every spring.

Rhomboid writes "Freon (R-12) has been banned for at least ten years. Everything made in the last 15 or so years uses R-134a as the refrigderant. R-134a has slightly different properties as R-12 (and isn't quite as good at cooling) but it is close enough that you can consider them more or less the same general thing."

Window units were almost all R-22. R-134a is actually more effecient than R-12 in automotive systems when engineered for it, it's just retrofits that suffer from decreased performance. Like Rhomboid said the details aren't anything to sweat as you have no control anyways.

paulsc writes "1) They don't always get the voltage or current on which they were designed to run. Operating on low voltage can cause their compressor and fan motors to run hot, and lead to premature failure of the compressor."

This is true, always plug the unit either directly into the wall or into a 12 guage extension cord. If your lights seriously dim when the compressor kicks in you should consider a different wall plug. I've also seen poor compressor reliablity in rural areas that experience frequent brown outs and overvoltages; what is your light bulb life like?
posted by Mitheral at 8:54 PM on August 8, 2006

no cottonwood trees... but maybe pigeon-poop? (nyc highrise).

as for the lights dimming, they do very slightly, but there's not much I can do about it; I only have one set of outlets in the room.

My guess is I've gotten low-quality units to begin with. I'm willing to try a panasonic or some other name brand next time, and to try my luck on craiglist for price (I cant believe people have bought a/c units for less than a hundred bucks). For about 50 its worth the risk!
posted by jak68 at 10:24 PM on August 8, 2006

as for the lights dimming, they do very slightly

Just a quick word of caution ... sometimes, when lights dim like this, it's because a circuit breaker is failing to do its job -- you know, breaking the circuit when it's getting overloaded. This can lead to electrical fires, as I once discovered.
posted by frogan at 9:01 AM on August 9, 2006