How do you deal with an overflowing air conditioner?

September 10, 2007 1:42 PM

The portable air conditioner (an AMCOR PLM 12000EH) in my server room keeps filling up with water. It used to operate without my ever needing to drain the reservoir. What changed? How do i fix this?

The server room doubles as a storage room, and is about 3m x 3m. It has a half-dozen running computers in it and other storage up on shelves. It's relatively well-sealed, and the A/C vents via a short hose into the neighboring room (a large auditorium). When the reservoir in the A/C fills up, the A/C turns off and must be drained. While the A/C is off, the room heats back up again, which is not so good for the machines. i've had heat-related hardware failures on machines in that room in the past (before the A/C was installed).

This particular A/C ran fine for 3 months without ever filling the reservoir. But two weeks ago, the reservoir filled for the first time. Since then, it's a non-stop chore to keep the A/C running. The ~1 liter reservoir fills in an hour or two.

I've gone back over the room and sealed what leaks i could find with duct tape. But i have to open the door to go into the room to drain the reservoir, so it's not like it's permanently sealed.

And unfortunately, i don't think there's a drain nearby that i can easily run a hose to, though i'm happy to explore other options.

What's causing this? How do i put a stop to it? Help me get back to doing the work i'm supposed to be doing!

posted by dkg to technology (6 comments total)

Is it possible that there was a change in the HVAC that services the rest of the building? Did they adjust the humidity by turning on a humidifier or turning off a dehumidifier? Or has your area been experiencing high humidity lately, and the site HVAC doesn't remove it? Is your site HVAC of the swamp-cooler type, or compressor/condenser?

I run one of these Amcor units in my server closet, and I've yet to have to drain it because the site HVAC sucks all of the humidity out first.

The unfortunate thing about these units is that the drain must be downhill from the nozzle on the back, and that's right at floor level.

Best suggestion I can give (and what I plan on doing if it becomes an issue for me) is to raise the unit and pipe into a larger receptacle (like a 5-gallon jug).

In my case, though, I will raise it and pipe it into the sewer of the bathroom on the other side of the wall.
posted by tomierna at 2:51 PM on September 10, 2007

Something caused the humidity in the room to increase. It could be something about the building's HVAC system, it could be the weather/season, or it could be something totally different.

The air conditioner acts like a dehumidifier, and as a result almost constantly pulls moisture out of the air. Most good portable units deal with this moisture by evaporating it into the exhaust air, but they can only deal with so much this way. If the humidity in the room is too high, it will fill the reservoir and cause the machine to shut off.

There aren't any real elegant solutions to this problem, if you don't have a drain accessible. You could put a dehumidifier in the room, which will produce heat but will take the moisture out and will probably have a bigger capacity reservoir than your A/C unit, so you'll need to empty it less often.
posted by Kadin2048 at 3:00 PM on September 10, 2007

Kadin2048 is right about the water coming from humidity, one of the reasons A/C works is because it lowers the relative humidity of the conditioned space making it feel cooler.

As a solution run the drain into a camping water jug. The handle makes it easy to carry and the spout style lid will prevent spills while still allowing the drain to enter.

More expensively you could pump the condensate to a drain. Using a pump will allow you to traverse quite a distance or access a drain location above your evaporator.
posted by Mitheral at 5:24 PM on September 10, 2007

Thanks for the suggestions, folks. tomierna, the building is large, but i asked the building manager and he doesn't know of any change in terms of new A/C or humidifier systems in the last month. I'm pretty sure the site A/C is condenser/compressor. There are condenser/compressor window units all over the building, at any rate. We're in NYC, and my impression is that swamp coolers only work in drier locations (In fact, i've only heard of them in Colorado).

I have a call in to AMCOR tech support, so i'll see what they think my other options are. I've also just found this device, which is supposed to be available for the series of A/C i've got. It's designed to vent extra humidity with the exhaust air, i think, like Kadin2048 suggests.
posted by dkg at 6:39 AM on September 11, 2007

OK, amcor support has been rather unhelpful, actually. Different representatives give slightly different answers, and the basic jist of all of the answers is "you can't do that with this model". One of the reps said you can't reliably use the nanomist with any model if no drain is accessible, and you don't have a outside window to vent it to. The same rep also said that you should not run the machine with a continuous drain, either, because the machine needed a partially full reservoir for standard operation. The other rep seemed to think that a continuous drain was fine to do. (of course, i'm not in a position where i can do a continuous drain anyway).

I've gone with the 5-gallon bucket strategy, emptied two or three times weekly. It's a pain, but it's not as much of a pain as having the computers overheat.

Thanks for the thoughtful and validating answers here, y'all. Wish there was a cleaner resolution.
posted by dkg at 10:32 AM on September 24, 2007

For reference, because of the winter months here in sunny Florida, our site A/C hasn't had to work as hard which now makes the Amcor unit do all of the de-humidity heavy lifting.

In late November, I hooked a tube to the unit and drained it into a 3 gallon gas can.

In late December, this was filling up every other day.

About two weeks ago, we had a plumber come in and punch through the wall to the bathroom's sewer and put in a trap so we could continuous drain into it.

So far so good :)
posted by tomierna at 9:52 PM on January 29, 2008