AC Types

Hi Haajee. Rapid cooling of the air passing through A/C evaporator fins results to local humidity saturation thus vapor liquefaction. This initially consumes much of the cooling capacity of the airconditioner BUT as air is progressively dried, it will also need less and less power to cool the next times it will pass the evaporator. Practically with this scheme humidity will never go down to unhealthy or even uncomfortable levels. Of course it is possible to spray the water again into the air stream (spray because I don't think it's possible with natural evaporation) but what's the gain? A drain pipe? S.M.

I do not think that is the purpose of the water pooled in the bottom. The water pooled can be used to increase efficiency by having the fan pick it up and spraying on the condenser coils. Evaporation of the water on the hot coils would greatly increase heat transfer.

Any water used to humidify should be fresh water. Water in any sump can become contaminated with bacteria. I do not think we would want to introduce this into the living space. I do not think the manufacture would design an air conditioner to do what you were told with possibility of this happening. Unless they installed some means to control bacteria in the sump. Like a UV lamp.

Either way there would be need for some type of drain. As the rate of water condensing on the evaporator coils and the rate of evaporation of water with just air blowing over it would be different. There would be need of elaborate controls to do so.

Unless the rooms has to be maintained for humidity for health reason. Which it would think that someone would use some better means. This would reduce the rooms comfort level. With out a drop in temperature. The higher the rooms humidity level the less effective our own bodies means of regulating temperature by sweating.

The technician pulled a fast one on you.

This water is meant to rust and make your AC look like crap sooner, have it drained! There is no real usefulness to add humidity in your room, unless it falls below 30% RH, static electricity and nose iritations at very low RH levels are less a risk than sitting water promoting molds and bacteria.

Is it a compressor-type unit?

One possibility the unit is an evaporative cooler (also known as a swamp cooler). Will not work in humid environments.

http://en.wikipedia.org/wiki/Evaporative_cooler

When the apparatus dew point temperature of the cooling is maintained below the dew point temperature of the return air dehumidification occurs. The coil is named as cooling & dehumidification coil. This water is mainly used for irrigation purpose at many places through proper condensate drain pipes. IF it is a window type air conditioners fresh air intake is negligible and hence this accumulated water on the tray may not be much useful except to spray it over the condenser coil to reduce the condensing temperature.

This water (as has been already said) is not clean enough to keep the humidity at a comfortable level. It should be piped outside into a drain. It is contaminated with dust and other dirt that is trapped in the A/C normally.....

All of the computer room A/C that I have seen over here have a special fresh water supply that is heated (inside the A/C) to provide the correct humidity, under control of some humidity sensor.

This may be an old fashioned method, possibly a modern one (I feel/guess) could use the wasted heat from the A/C.......but still fresh clean water!!!

CR4 geeks?

Your son is in the hands of a crackpot who knows nothing about the pyschrometrics of air or anything else pertaining to air conditioning. The building code in any jurisdiction plus good practice requires a condesate line be run to an open drain. He should fire that installing contractor on the spot.

Lou Bindner

Thanks all for their informative replies.

But one thing remains unresolved in my mind:

In my country I have not noticed an AC without a drain-pipe.

Why I see 2 types of bottom trays - 1. with a drain-pipe draining almost all dripped water and 2. A bottom tray always full and only drains above the upper edge of tray.

I have written to some of the manufactures to put some light on the point.

Hope if they can clear it

NB: What's the problem with google not listing addresses of manufacturers.

Sorry about Global spoecs.

Nothing at all on their sources about Window AC Units

My window air conditioner uses the water to cool the condensate fins. You should see the mold in the fan area that blows cold air into the house! It is only matched by the muddy slop that builds up in the condenser area. I have to remove that mess with a wet vac, quite a chore.

The water probably improves the efficiency of the unit, but it also corrodes it out. The aluminum fins eventually corrode away or get so clogged as to be ineffective. Planned obsolescence.

If I had a good place to drain it to, I would open the lowest drain and pipe the water away. Maybe cost more electricity, but the unit would probably be more mold free and not corrode away.

Regards.

In my son's case I drilled a 1/4" hole on the back side of Water Tray and all the water dripped away as soon as it is drips inside tray.

But it will be dripping continuously and you have to arrange not to mess your living area.

Just a plastic duct available and easy to work.

I have just posted a query to Fridgidare. Lets see what they say.

*************

1. Why it is not used in all Window Mounted AC Units.

2. In Your model RA087AT7 there is no drainpipe fitted and water flows out in room as the bottom is gets full.

Is there any advantage of keeping water in the bottom tray?

Hope for a detailed technical reply.

Query sent @

http://www.appliancepartspros.com/Appliance-Parts/dnb-dim-drain-water-pipe-item-number-ap5180271.aspx

Your question has been received, and it will be answered by our dedicated staff shortly.

http://www.appliancepartspros.com/Appliance-Parts/dnb-dim-drain-water-pipe-item-number-ap5180271.aspx

*******************

The reply from one of the major vendor of Window AC units is:

Subject: RE: Query (#8859-238832042-6698)

Thank you for getting in touch with us. I am not exactly sure what you are referring to. We have never heard of a window unit that has a water drain pipe. Window units just drip the condinsation from the backside of the unit. If you can clarify specifically what you are talking about please let us know. Thank you for contacting us at Living Direct please feel free to contact us via chat, email or phone us at your convenience.

Regards.

At last found the answer!

From LG User Manual: MFL42491701_manual.pdf