How long should window air conditioners last?

Question

I have a unit that I haven't used in 3 years. I plugged it in and it only blows cool air, not cold. Do the refrigerant in these units "wear out" from non use?

Answer 1

Hello Yan W

Air conditioning equipment SHOULD last for a very long time if properly maintained.  I know of many units that are very old and still working properly.

Proper maintenance requires periodic cleaning of both the inside and outside coils as well as keeping the filter or filters clean.  

If your unit was working well when you last used it three years ago, and it, and now, it only works weakly, it MOST LIKELY has developed a REFRIGERANT  LEAK.  Because you said it emits COOL air, indicates the compressor IS RUNNING.  Refrigerant  does not degrade from non use, but if some leaks out, your unit will run poorly, as you describe.  The refrigerant is under pressure at all times, and can leak whether or not it is run.  The refrigerant itself does not “wear out” with use or non use.  The compressor can wear out from use, but of course cannot wear out if not run.

Refrigerant leaks can be caused by corrosion of the refrigerant lines, coils, and connections.  Corrosion is more rapid in wet conditions and especially if there is an accumulation of dirt on these parts which traps the moisture and enhances deterioration.  It is also possible that the unit had a very slow leak right from the manufacturer, and just now, enough has leaked out to cause you to notice the poor performance.

The refrigerant is in a “closed, sealed system” and as long as no leaks develop will continue to work.  Refrigerant can be added to a system, but if the leak is not repaired,  it will just leak down again.  Frequently, it is not worthwhile to repair and refill window units, especially older ones.  Often, even the newer ones are constructed in such a way as to render repairs impractical.  Newer ones are being made with higher efficiencies, also.  (EER, and SEER)

You did not say how old you unit is, or how many seasons it has been used.  It is not likely that the coils and filter became dirtier with non use, but the prudent thing to do is to check for clogged evaporator and condenser coils, and filter, and clean them if necessary.  If your unit still fails to perform properly after you know your unit is clean, then you will need to have it repaired, or purchase a new unit.

Good Luck