AirCon n00b and a missing manual

August 1, 2008 7:23 AM

I just bought a portable Air Conditioner from ebay. Is it working right?

This is the unit in question. It is an "airforce WAP 358DB". It didn't come with a manual, and I can't find anything online.

I've never owned an aircon unit before, so I'm not 100% what's to be expected (except the cold air!).

When I switch it on the compressor comes on straight away and makes one hell of a noise. A very loud humming. Very loud. So loud it's hard to talk standing near it and it makes the case vibrate.

It doesn't always come on though. Sometimes I'll switch it on and it'll hum away churning out the cool.........then BAM the compressor kicks in after about a min.

If I set it to dehumidify the compressor switches off and stays off, but I have no temperature control.

There is (what appears to be) a water level indicator on the control panel, but I'm not able to find any thing on the equipment itself where water might collect. There is a small nozzle on the bottom of the unit that drips though.

They sold these units here in the UK from B&Q but no longer do this model. It's possible that the model they do now is almost identical, so I may try and obtain a manual for that.

1) Should the compressor be THAT loud?
2) Why doesn't it always com on?
3) What's with the drippy hole on the back without anything to collect the water? Am I missing something?

posted by lemonfridge to technology (8 comments total)

IANAACG (...an air con guru)I just got a portable unit earlier this year so here's my thoughts...

1) Mine isn't that loud, but it is noticably louder when the compressor kicks on compared to when just the fan is running.

2) no idea why it doesnt come on sometimes, mine does this too. Either it comes on in a few minutes or I get impatient and fiddle with the temp setting and it turns on.

3) My unit has a large overflow tank attached to the back. Right now it is very humid so I am emptying it every second day. The tank is optional but when the internal resevoir is full, the cold stops :/
posted by utsutsu at 7:41 AM on August 1, 2008

internal reservoir? Mine doesn't seem to have any kind of access for anything internal. Hmm
posted by lemonfridge at 7:43 AM on August 1, 2008

1) Some of them are noisy as hell.
2) If there's residual pressure on the high side, the compressor may not need to kick on right away. That you're in the UK suggests that the unit never needs to use full capacity, since really, you don't see the temps that the unit was designed for.
3) the water indicator is to tell you that the drippy thing is clogged.

In a/c units, the cold coils often condense water vapor out of the air. (Warmer air can hold more vapor.) This is especially true in the "dehumidfy" mode. This water has to go somewhere - usually you run a hose outside or into some means of collection.
posted by notsnot at 7:44 AM on August 1, 2008

It has a big fat hose out the window (why so big?!) that churns out warm air when the compressor is on.

I've just found that the compressor comes on when I set the desired temp to something lower than the current temp. At least thats what is appearing to happen.
posted by lemonfridge at 7:47 AM on August 1, 2008

I've just found that the compressor comes on when I set the desired temp to something lower than the current temp.

Which is a good thing, or that air conditioner would be running right up until it caused the heat death of the universe.

There is a small nozzle on the bottom of the unit that drips though.

This is probably where the water hose (different from the air hose, which is where the unit is pumping the heat from inside your room) was once connected. I guess you'll have to put something there to catch the condensation as it drips out.
posted by A Thousand Baited Hooks at 7:57 AM on August 1, 2008

It has a big fat hose out the window (why so big?!) that churns out warm air when the compressor is on.

The heat that its sucking out of the room has to go somewhere. If there is only a single hose it is probably taking some air from the room and exhausting it to cool the condenser (warm) side of the system. Some portables have two hoses, both of which go outside, which draws outside air over the coils then exhausts it again.

I've just found that the compressor comes on when I set the desired temp to something lower than the current temp.

That sounds like its working properly.

I know with central A/C, you aren't supposed to shut the compressor off and then on again immediately. My A/C unit, if it has recently cycled, will wait a bit before coming on again, even if the thermostat indicates that the system is on, which leads me to believe this "smarts" is built into the compressor unit (outside) or the air handler. Perhaps your portable unit has similar limitations.
posted by kableh at 8:24 AM on August 1, 2008

It sounds like it's broken. Dehumidify mode should run the compressor.

It can be a low charge of freon (or whatever it is), or perhaps a sensor that's gone bad. See if there's some kind of level sensor for the water.
posted by gjc at 6:06 PM on August 1, 2008

what I know from personal experience:

(a) portable a/c is not nearly as efficient as window/wall ones. also much louder. super-high cooling btus are advertised, but a window unit with 20% less btu will do a far better job.
(2) the internal water tank is not accessible like a traditional dehumidifier unit; the idea is that what the a/c condenses, it tries to convert to vapor and pass it out the exhaust hose. in practice this often doesn't work over time as the condensation rate is much greater than the evaporation rate, and when the tank fills up the compressor will shut down but the fan will stay on until it can evaporate enough of the internal tank.
(vii) unplugging the water spout and draining into a pan or what have you can be helpful but needs watching else WATER DISASTER.
posted by dorian at 9:02 AM on August 2, 2008