How bad are window AC units (old and/or new) for mold allergy?
March 9, 2018 3:36 PM   Subscribe

I'm trying to find a new apartment in Chicago. A lot of older high-rises, which would otherwise be a good fit, have window air conditioner units. I'm seeing a lot of warnings about mold in window AC units.

Assuming I'm not going to up and buy a new one (most of these seem to be carefully and painstakingly fitted into the windows of the buildings), is it possible to clean or assess them to make sure they don't have mold? Do all of them have mold?

Assume I'm extremely interested in avoiding all mold. It seems to really bother my eyes.

The newer buildings, with central AC, overwhelmingly have either laminate flooring (avoiding for other reasons), or carpet (often has a perfumey smell from carpet cleaning, which gives me bad migraine headaches with nausea). Non-high-rise buildings are likely to have stairs (I'm saving my knees for other activities), and ground-floor-apartments are likely to have mold issues of their own.

So, finding a way to make window AC work for me would be extremely great.
posted by amtho to Home & Garden (15 answers total) 3 users marked this as a favorite
 
My only data point: I have mold allergies and my window a/c has never been a problem. If they are angled so they drain properly, I don't see why they would be.
posted by metasarah at 5:36 PM on March 9


I'm getting to the point where I read an air quality question and say "Oh, that's amtho again." I point this out only because I'm wondering if there isn't maybe an element of obsessive thinking in your question-asking strategy. A physiological response to environmental conditions that degrades your quality of life is a big deal and I don't mean to trivialize that, but if you were asking this many dating questions about one topic someone would say "have you considered seeing a therapist?" I'm not sure which kind of expert you want to see -- could be a therapy thing, could be an allergist or respiratory specialist, but.. it seems like you have very extremely particular needs, and I guess I'm wondering how much of that is legit need and how much is other life factors that could maybe be addressed in other ways.
posted by Alterscape at 6:01 PM on March 9 [6 favorites]


Window units typically have a filter that the air blows through on the way to the inside. Any mold should (should) be on the outside, away from where your air is. It really shouldn’t be anywhere, because there’s a drain in the bottom, but still. Make sure there’s a filter, and change it, and you should be OK.
posted by Huffy Puffy at 6:34 PM on March 9


Oh! And running the air through the AC will dehumidify it, so overall your living area should have less mold.
posted by Huffy Puffy at 6:34 PM on March 9


Window units typically have a filter that the air blows through on the way to the inside. Any mold should (should) be on the outside, away from where your air is. It really shouldn’t be anywhere, because there’s a drain in the bottom, but still. Make sure there’s a filter, and change it, and you should be OK.

Functionally you're correct, but there's not even a filter, it's a physical barrier, because a filter would just allow all that nice cool air you're producing to float outside. The filter found on air conditioners is for filtering out dust particles from the ambient air as it passes into the air conditioner; this is what is to be cleaned or replaced regularly for sure. They're usually sealed up as tight as can be. Here's a good illustration on how they actually function. But yeah, AC units don't suffer from mold problems on the inside, unless something has gone terribly wrong. Even old shitty ones won't build up mold on the inside.

Older units are garbage for a whole host of other reasons, namely the fact that newer ones are very, very energy efficient (leaps and bounds!). Replacing an old unit with a newer one is a great idea, but not for mold abatement.
posted by furnace.heart at 6:44 PM on March 9


Oh, evaporative coolers, sometimes called swamp coolers function by pumping more humidity into an area and very much can cause mold problems; while they do exist, they're not really found in the form function of a window unit very often.

They are an older design than modern air conditioning systems, and honestly if someone on the internet is shouting about 'old air conditioners and mold' they might not be picking these differences apart.
posted by furnace.heart at 6:48 PM on March 9


Mine got moldy - I hadn’t turned it on in some months (I don’t like AC and will do almost anything to avoid using it short of trying to sleep in 85+ degree heat.) I could smell it as soon as I turned it on. I wanted to clean it out but while apparently that is possible, on researching it seemed like a huge giant PITA. It was free, a gift from a moving friend anyway. So I put it out on the curb with a sign explaining that it was moldy but worked; it was gone in minutes. I’m going to buy a new one when I get back to Asheville. They aren’t super expensive, like $200 or even less. What I would do is not sweat this, find an apt you like, turn on the AC and if it smells - the smell is immediate - plan on replacing it.
posted by mygothlaundry at 8:22 PM on March 9


Dude, if this weren't legitimately difficult, I'd have solved it already. Therapy would not help here. Argh.

I have the support of appropriate medical professionals (the doctor who originally sent me to a pulmonologist, the ophthalmologist who has dealt with my keratitis so far), but I'm pretty sure that if I could just avoid the things I'm allergic to, a lot of my issues would resolve on their own.

This question is me hoping that the window AC / respiratory problems link is overblown (despite various web articles and rental agent information to the contrary) so that I can just relax and get an apartment like a normal person.

I'm not sure I could replace one of the window AC units in a high-rise apartment building, and I worry that the response to "I have a mold allergy that you can't experience directly, please pay hundreds of dollars to replace this window AC unit" would probably be "hey, are you sure you aren't imagining it" rather than any real help.

I included the other info about laminate floors, etc., to ward off suggestions that I just look at newer construction with central air.
posted by amtho at 9:54 PM on March 9 [1 favorite]


I'm not sure I could replace one of the window AC units in a high-rise apartment building

Maybe I'm missing something obvious here, but why not? They're window a/c units. People install and uninstall them constantly. I brought mine from my last place. My downstairs neighbor actually takes them out for (I assume) the winter. Their flexibility is one of their main advantages. I wouldn't even assume that the a/c necessarily would come with the place; where I live, they usually belong to individual tenants, but that of course could vary by market or even individual building. If it doesn't, then bring your own new one, no worries to have. (Or don't have one at all, if it makes you feel better.)

This question is me hoping that the window AC / respiratory problems link is overblown (despite various web articles and rental agent information to the contrary)

Respectfully, and without in any way questioning your physical issues, your completely understandable anxiety over them might be interfering with your ability to judge the credibility of your sources (there is a whole Internet ecosystem that just thrives on selling you distrust about your environment) and relative risk. For reasons discussed already, this is not a very common issue for window a/c. Further, if there is mold, it should be pretty visible within the unit--it's not like there's much room for it to hide--and it smells, so there shouldn't be much difficulty in identifying a problem if it does exist. And then, assuming the a/c is owned by the building and your landlord is even vaguely diligent, replacement should be irritating, but not an epic journey of misery. So this concern should not be causing you to rule out a large class of otherwise desirable apartments altogether.
posted by praemunire at 12:05 AM on March 10


While it's not the subject of my question, mold in an apartment unit is seldom visible during a casual pre-lease inspection. It wouldn't have a smell, either. Before putting a place on the market, a landlord will clean visible mold and possibly re-caulk the bathroom, but if it's under fresh paint, in crevices around windows, or behind baseboards, it will come in not long after you've signed your lease, especially if you move in right before warm weather hits.

My main concern here, though, is with whether it is possible to assess or moderate the risk of mold inside a window AC unit that I don't own.

The degree of attention a risk deserves is a product of probability (here, low-ish, but not vanishingly small) and the magnitude of the potential consequences (here, very large). For me, these two factors together tell me that this risk merits going to a certain amount of trouble.

My whole question here is because I already know that random Internet sources are suspect! Why are you imagining I have some kind of anxiety issue just because I'm hoping (apparently against hope) that someone here might have better information?

Also, I seem to remember that those things are heavy. Plus, the places I'm looking at have identical AC units in all the windows, so I think they might be owned by the building. If a little research can save me from having to deal with this, or with the impossible situation where I'm unable to replace a bolted-in appliance, then, yes, I'm going to do the research. You reading this is part of that research.

Does anyone have experience with window AC in a high-rise apartment, or with sensitive sinuses / mold allergy and window AC units anywhere?
posted by amtho at 3:21 AM on March 10


Here's a good article on how to clean an a/c unit.

I wouldn't assume that all the units have mold already. I lived in an apartment with a window a/c unit for three years and never had issues, and I have a severe mold allergy and lived in a humid environment.

Turn the unit on when you're looking at the apartment . Does it smell musty, like old library books? Could be mold and probably easy to clean. Does it smell worse? Very likely mold and probably not easy to clean. Take the front cover off and look inside. Have a flashlight handy. You'll be able to see mold if there is any. You can probably remove the filter. Do that and look at it.

It's also perfectly acceptable to ask if a mold issue becomes apparent in the a/c unit at some point in the future that isn't mitigated by cleaning if it would be acceptable to replace the unit at your cost but with the building's help in installing (which you then take with you if/when you leave).

Having a mold allergy myself and smell sensitivities, I would look more askance at carpeting and laminate than I would at an a/c unit.
posted by cooker girl at 7:29 AM on March 10


If there are window AC units throughout the building, they have a system for installing and replacing them. They will need to replace some of them from time to time. Some places will take them all down in the winter.

I recommend you ask when you visit the building:
1. Who do the AC units belong to (so who buys a new one when it breaks), and if you wanted to buy your own or already had your own, is that OK, and
2. Do they want to install/remove them for you, or do they want you to do it. I'm pretty sure for liability reasons they will want to handle the installation (so some dumb resident doesn't drop one onto the street--which is unlikely, but not impossible given enough units). Again, this is a standard thing that they will expect to do from time to time.

They're designed to be easy to get in and out. They can be quite heavy, but the weight is mostly on the "inside", and you set them on the window ledge, to bear the weight, when you put them in. Then you close the window over them and you only have to tilt them to match them up with the frame. You don't really even have to bolt them in; that's just to keep burglars or children from tilting them in and climbing through the window, though for liability reasons I'm sure your landlords will want them fastened into place.

You can change the filters on a regular basis. You can clean the inside vents. Worst-case scenario, you can turn off the AC in a specific room until it gets fixed. You could remove it, but that's probably actually worse for you because now the mold is fully inside your space. Worst-worst case, you can block up the vents or the whole thing with cardboard and duct tape.

The outside part of window units are designed to drain water, because they're a ventilated electrified box sitting outside your house, so they get rained on. On the whole, I would expect them to provide you a cleaner and drier environment than if they weren't there.
posted by Huffy Puffy at 7:41 AM on March 10


A/c units are heavy. I am a nonbuff woman. Like you, I live in a large city, where it is easy to hire someone for not excessive $ to install and remove them if the building doesn't handle it (heck, it's a standard service listed on Handy). It's not actually a hard process if you have the arm strength to do it and a few simple tools. It's never taken my guys even an hour to install or remove my two units. And if the building owns the a/c, they will have to have a process for installing and removing the units themselves.

Most window a/c units have removable front grilles. You can literally open up the device and inspect the innards for mold. If you're touring a unit, you can check this.

The filters in most window a/c units are also designed to be removable. In fact, you're supposed to clean them (of dust) regularly.

I am only saying this last bit because I've had my own run-ins with health anxiety, not to hector you or dismiss your concerns. I am in no way whatsoever challenging your allergies or trying to diminish any past issues you may have had.

Why are you imagining I have some kind of anxiety issue just because I'm hoping (apparently against hope) that someone here might have better information?

Because:

(a) You're asking that people refute random and questionable sources, but apparently no information is adequate; it's not clear what would be;

(b) You have built up unlikely scenarios about why it might be impossible to remediate the risk (that a/c units designed to be removable and replaceable wouldn't be);

(c) You identify a risk that certainly does exist (landlords covering up mold problems) but have attached it to this particular scenario when it could materialize in almost any apartment situation, including central air and no a/c at all.

This is all a very familiar style of thinking to me, and I feel bad seeing someone else potentially in this situation and apparently finding it really hard to find any housing at all. That's all.
posted by praemunire at 9:14 AM on March 10 [1 favorite]


no information is adequate; it's not clear what would be;

Personal experiences with high-rises with window AC units, OR personal experiences with mold allergy and window AC in any context are both very relevant.

unlikely scenarios about why it might be impossible to remediate the risk

I have come up with scenarios that I hope are unlikely specifically so that others may address them. I have not "built up" anything.

have attached it to this particular scenario when it could materialize in almost any apartment situation, including central air and no a/c at all.

That's potentially true, but I'm trying to rule out its being more probable with this kind of AC system.

Maybe for you it would be a lot less of a crisis to have moved into a moldy apartment. For me, it would derail what I plan to be a very busy, focused, exciting, creative time, spending a lot of money, and potentially affecting my health in ways that would be difficult to recover from. So, it's reasonable for me to learn as much as possible before proceeding. It's not a reflection of an emotional state (except perhaps that I haven't put as much time into it as I should, before now, since yeah, I feel a little self-conscious).
posted by amtho at 2:34 PM on March 10


I can't stand moldy AC. Local here. Easy answer: the handy person employed by the building who actually deals with these apartment AC units (either the window or the ones in the box) can generally be bribed to get you a different or new unit. Cookies are a good start, beer is better but hard cash/gift cards will get you to the top of the service calls. I have seen AC units getting replaced for being to loud and another just for leaking. If they can't be bribed you still have options - clean it your self or fight management.

Clean it: Unplug it. Mix a solution of ½ cup bleach, 1 tablespoon dish soap, and a couple of gallons hot water. Note: this may involve taking the front of the AC off, but you don't have to take the machine out of the window/box. First, start with the filter panel - pop that open and if it's a plastic mesh toss the filter in the sink with enough cleaning solution to cover and let soak for 15 or so. If it's foam - just buy a new one. Scrub both sides, and find a spot for it to dry. Youtube will help with the next step but essentially you'll unscrew the front panel and/or it's likely held in with tabs, but you should be able to pry that off and get at the cooling coils. I've done this many times. Vacuum it out. With a sprayer and/or brush gently get in there and get at all the coils with the solution and let it sit for 10. Rinse it all off with some fresh water. Dry it out as well as you can and then put it back together. Then turn it on fan mode to continue drying the rest of it. It will smell like chlorine for a little while so be prepared to air out the room.

The foaming cleaner things were easier, but they were perfumed and not as effective as the moldy smell quickly returned.

The long hard answer: Fight. But really it isn't a fight, you have a right to a livable space. So more like hassle! First up, keep in mind that if you don't like your AC it doesn't get thrown out - usually it just gets re-purposed elsewhere and the management will be motivated to solve your issue. Also know that Chicago tenants have a variety of rights including the power to withhold rent and/or repair & deduct to specifically address problems like mold. It shouldn't have to get that far - the bigger buildings generally have "professional" management who are not interested in any of this sort of problem. Just sending a letter registered mail is usually enough - and there are resources for Chicago tenants for that process of getting repairs, withholding rent and generally getting it fixed.

I avoided using the building units and always had my own AC's installed. I've replaced 1 unit in a decade after it got moldy. For liability the building will want them installed correctly.
posted by zenon at 10:35 PM on March 10


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