← Back to context

Comment by jp57

7 days ago

Not specifically about drinking water or jackets, but I've often wondered why air-conditioning condensate is plumbed into the sewer instead of someplace useful. An A/C is a water-from-air device, and they run in much of the year in most homes in the southern US.

The typical design that I've seen plumbs the main condensate drain into the sewer, and usually has an overflow that dumps somewhere harmless if the main line clogs. (like out of the ceiling over the bathtub or out of an exterior wall in a visible location, so you can see it and fix it)

The few times I've seen the overflow, it's been quite a fair amount of water. Certainly enough to help with garden irrigation, if nothing else.

Since A/C (or similarly, dehumidifiers) function by moving a large volume of air over a set of chilled coils, one consequence is that dust tends to accumulate on those coils, and be mixed in with the resultant condensate.

If you're looking at grey-water applications (e.g., watering plants, flushing toilets), this isn't a major concern. But if you were interested in drinking that water, you'd have to run it through additional filtration steps, and it would tend to clog those filters pretty quickly.

(I discovered this tasting the water from a household dehumidifier tank some time ago.)

The constant dampness also makes the same condensate tend to hold mould or fungus, which may not be especially conducive to health, whether of humans, pets, livestock, or even plants.

Climates in which A/C is most likely to produce a large amount of condensate (humid climates) tend also not to be especially water-constrained, so that the optimisation of salavaging A/C water is limited at best.

Not to say it's never useful, but there are more considerations than might be initially apparent.

It's very common to plumb into grey-water systems where they're installed, because you're right, it's perfectly useful water. Plumbing it into some kind of cistern like a rain catchment system would also make sense.