Water Cooling

the release of heat condence and transform into water?

Okay - things to know about condensation. There is relative humidity, dewpoints and condensation.

For any specific temperature of air, it will hold a fixed maximum amount of water vapour. It can hold less and under rare circumstances more, but we'll ignore that for now.

Okay, I don't know off hand the exact maths but the principle is this.

You can have air at 20 degrees with a relative humidity of 40% This would be a cool feeling room, but not that cold. Now, if the air were to heat up (say you turned on an electric fire, the air would heat up. Assuming you have no source of moisture in the room, the relative humidity will drop. Warm air can hold more water than cold air, therefore the relative humidity is less, even though the actual amount of water in the air is the same.

Right, now you cool that air down again, the relative humidity will rise (assuming you are not using an AC unit which de-humidifies).

So, let's take our air and place something very cold in the room. The air around that thing gets cold. If it gets cold enough that the relative humidity reaches 100%, then we hit dewpoint and moisure is formed on the surface of the cold thing. So, if the temperature of the thing is cold enough to create a delta rel humidity to 100%, you get condensation.

An aircooled watercooler cannot get below room temperature fortunately because we are using room air to cool the water itself, so the waterblock cannot get below room temperature and we cannot get condensation.

Only when we use more extreme methods, such as peltiers or vapochills are below room temperatures generated, and that is when we must be careful of condensation.

Please note, if you create an 'open watercooler' where you have mains tap water running through your block and out a drain, rather than a radiator cooled closed system watercooler then you will very likely get temperatures below room temp and have to guard against condensation.

Hope this makes sense. It would be possible to calculate, for a given room temp and relative humidity, what the coldest an object may be before condensation occurs, but it is usually not much below room temperature unless your climate is very dry.

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email for application details<P ID="edit"><FONT SIZE=-1><EM>Edited by peteb on 05/29/01 09:47 PM.</EM></FONT></P>