Water From Refrigerative Air Conditioners.

Hoping some mechanic or engineer can help here.

I live in a pretty non humid climate. It is hot though and air con is a must.

The water coming from the systen annoyed me as it was going no where. I just rigged up a simple catchment where I collect the water and use it in the garden. The overflow goes into the cats water bowl so he has clean pristine water. Does he like this? No- because if it is hot he wants to lie inside in the air conditioning and watch television .

Anyway, I was wondering if the amount of water produced from air conditioners is collected and reused at all. I believe it is virtually distilled and if my little system can produce 50 litres a day, commercial systems must do a lot more.

Is the water recycled?

It’s not distilled, it’s condensed. It’s going to be full of dust and everything else that’s floating around in the air in your house. I wouldn’t consider it pristine at all.

And no, commercial places don’t recycle it. If you walk into a Sam’s Club (for example) look along the big freezers and coolers and you’ll see the PVC pipes which go right to the floor drains. That the same thing.

However, it’s not harmful at all is it?

I don’t know…what’s in your air? Any mildew, mold or fungus? Dust mites or cat fur you might not want to drink?

Distilled water is something similar to the steam coming off a pot of boiling water. The water coming out of an AC is the same as the water the collects on the side of a cold glass. It looks clean but it contains any thing that’s floating around in the air with it when it condenses. Personally, I wouldn’t drink it after all the evaporator coils I’ve cleaned out.

Go take a look at your AC coils and filter and then make a decision.

But… if that sort of stuff is in the air anyway, wouldn’t people be exposed t it inside?

I’m not trying for an argument here but I would really like to know if I am going to kill my cat.
(And can it/ does it get recycled?)


I’m sure some super green places do something with it, but in general, no, it goes right down the drain or gets dumped outside.

I agree with the other posts that the water is not just like distilled and may be quite dirty. Will it harm your cat? Probably not, but given that using tap water instead probably costs pennies a month, is it really worth it to find out?

As a side note though, that 50 liters a day strikes me as a lot, especially if you live in a fairly dry area. I live in a fairly humid area and while I have never measured my AC’s output I would be surprised if it were close to that much while cooling 2300 sqft.

Also note, the evaporator coils on your system could contain lots of solder with lead in them, and minuscule amounts of lead could leach into the water. I put this risk as being incredibly tiny.

Have you tasted the condensed water? I have on a lark a few times, and it always, without exception, tastes “stale.” If I was a cat not only would I not drink it, I’d probably pee on your computer for giving it to me.

I concur. My 3-ton unit in a very heavily humid area probably does not make 20 liters.

Side question: in most window a/c units, the internal air and the external air are kept separate. So what is the mechanism whereby the condensation is transferred to the outside?

The water is created on the inside unit and there is usually a small channel on the bottom pan where it can run under the (styrofoam) insulation to get to the outside part of the unit.

Stationary engineer here, maintaining two 14 story buildings over 400,000 sq feet. The cooling coils in both buildings have pans under them that collect the water. The pans have drain lines that lead to the buildings roof drains. Inside the building are a few smaller AC units for the server rooms. The condensate is collected and pumped into the buildings waste lines.

Window AC units are desinged so the water will collect on the bottom and drain by gravity to the back (outside) of the unit.

Me I would not drink the water.

Automotive guy here. Car AC units also condense water, lots of water as they are mostly cooling outside air.
If you saw the muck, mildew and crap that collects in the evaporator case there is no way in hell you would drink the condensate.

It is all water with varying levels of contaiminats. Yes condensate if full of yuck frrom the air.

Note, I believe code forbids loading sanitary sewers with it.

Those with condensers in the attic need to be careful about keeping the drains clear.

I used to use it in stuff like car radiators and batteries. Rain water is easier to collect. Low mineral, but again air yuck.

This would be a good place to remind everyone to clean/replace the filters in AC units, and to hose off those condensers regularly.

Dirty filters and grubby condensers make the AC work HARDER and burn up more $20 bills while keeping you cool!

I was just at a lecture by a plastering expert today, and he showed pics of old brick buildings with window AC units. Apparently the water that drains out is acidic and eats away at the bricks and mortar.

I wouldn’t give it to your cat either. Collecting on and pouring over the various parts of an air conditioner will definitely add a decided ‘funk’ to it, possibly potentially harmful (certainly not extra healthy!)

As an aside, even if you pour it down the drain you’re not really ‘wasting’ water. As others have said you would not be pouring pure, distilled water away, just (somewhat funky) water condensed from the air. And even if it goes down the drain or just pours right onto the ground it will eventually evaporate into the air again. Circle of life and all…

Something else to add, it’s not just that there’s stuff from the air in that water…it’s concentrated stuff from the air in that water. Look at the filter from your AC unit (window or central). Would you really want to put your mouth on that and take a good deep breath? Probably not, but that’s nothing more then dust collected from the same air you’ve been breathing.

Indeed. On humid days, my basement smells like, well, a basement. I have a dehumidifier (which, for this discussion, is basically the same thing as an AC: a cooling loop on which water condenses before dripping into a tank). Believe me, the water in that tank smells like concentrated basement. I wouldn’t dare give it to a fellow mammal.

I’m not sure I follow this line. It’s not as if the water is run through the filter.

Also, I’m not sure that water in a basement collection has a lot of similarities (from what I understand). This unit is simply outside and ordinarily the water drains away so there is no collection- until I piped it into a basin.

However, I acknowledge your points about it could contain crap and I have removed it from the cats water supply. It is now used for the garden.

Also, on reflection, I probably did over estimate the amount produced, but I don’t think it is by much. I’ll run a test over the next few days and see how much I dod collect. I know the quantity did surprise me.

(Sorry to not respond for a few days- real life caught up.)

Wow, you’re really hard to convince.

The condensate from your a/c evaporator collects, pools, and runs off to whatever drain is provided. The place it collects and pools is moist most of the time. Things that like to grow in moist places grow there. Algae and mildew mainly and some bacteria. Any water that drains out of your a/c contains that algae, mildew and bacteria.

I’d stick to watering your flower pots with it.

ETA: Okay, sorry, you’d already been convinced to not drink it. (As evidenced where I quoted you):smack: