I have an old wall unit in my apartment (renter). It’s at least 12 years old as that’s when I moved in. What happens is that after I turn it on, ice, or some other whitish substance starts to coat the inside of it. It doesn’t take long for the icy substance to appear, just a few minutes. If I let it go for about an hour, I’ve pretty much got a polar ice cap in my air conditioner.
Is there something leaking? Something not good for me? Is this is a sign that the unit is about to die? Is it hurting its energy efficiency, which is pretty bad to begin with.
Ice forms on the evaporator coils of an air conditioner for a few reasons, including:
[ul]
[li]Insufficient refrigerant[/li][li]Excessive cooling capacity (BTU/hr rating) for the area to be cooled[/li][li]Outside temperature too low[/li][li]Insufficient airflow (check filter)[/li][/ul]
Given the age of the unit, the first and last items are the most likely possibilities. If the ice is forming as quickly as you say, then cooling capacity is probably not the issue. Definitely remove the front panel and clean or replace the filter, since clogged filters are the number one cause of window AC unit performance problems.
Thanks, I doubt it’s the outside temperature as I live in Southern California and it’s mighty hot here.
I took the cover off and I couldn’t even find a filter. So either I’m looking in the wrong place or the filter has disintegrated over the years. I know that this unit has NEVER been serviced since I’ve moved in.
But I still need to know if it is safe to operate in this state.
Safe as in “not going to explode and cause a fire”, probably. However, running it much in this condition can overload the compressor, causing premature wear and possibly failure. Since the ice on the evaporator is a pretty good insulator, you’re not getting much in the way of cooling, anyway. If you can afford it, new units are fairly inexpensive. Be sure to properly size it for the area you intend for it to cool, using a calculator such as this one.
Thanks.
Since I’m a renter, I am getting on the manager’s case to do something about this. August and September in Southern California without a functioning A/C is not a pleasant thing.
I hope you don’t think I’m insulting your brain power or anything, but since I’ve seen this happen a lot: Have you set the air circulation to “fresh” or “recirculate”? You almost always want the latter as A/C works mainly by removing moisture from the air, chilling is a very nice side benefit from how that is done.
If your A/C is always getting fresh air from outside, it will constantly have to remove moisture from the air and ice build up is more likely.
Definitely not insulting my brain power. When it comes to home repair, I’m an idiot. I’ve never understood which setting was best.
I’ll check when I get home.
Regardless, I think the unit needs to get serviced as no repair person has checked it since I’ve been there and during some repairs to the upstairs units, contractors have dropped stuff on the unit and it’s full of dents.
Curious statement. I would argue that an AC works mainly by allowing a refrigerant gas to expand thereby removing heat from it’s surroundings. Dehumidification is a nice side effect of that process. The way you put it sounds like the thing won’t work in completely dry air, which, of course, it will.
I agree about the air circulation setting, however. I haven’t seen this on newer units, but older units did indeed have such a switch. Newer units still can draw in outside air, but they do so with a “Fan” setting, typically, which does not run the compressor at all.