> 20 liters of water can store enough heat to last comfortably through
> an afternoon of hamming, and overnight the bucket cools down almost
> to room temperature. To work a 48 hour contest, some sort of heat
> exchanger with fan would be needed, or the water would need to be
> replaced every several hours.
The point here is that even 10 liters in a system with a small radiator
and fan would be more than sufficient. Extend the hoses outside the
shack and one has essentially noiseless cooling *and* removes the heat
from the shack which can be a blessing in hot conditions (like Florida)
on a small shack.
73,
... Joe, W4TV
On 5/1/2012 4:37 PM, Manfred Mornhinweg wrote:
> Al,
>
>> If you don't mind, could you briefly describe your cooling system?
>
> A bucket under the desk, holding some 20 liters of water. A small
> submersible AC powered pump in the bucket, the kind sold in home
> improvement stores for decorative indoor fountains. Plain half-inch
> garden hose up to the amp, and back down. The cool blocks are made from
> copper sheet, soldered together. The shape is like a small finned
> heatsink with a cover on the back, and two end covers with hose nipples
> in them. The base plate is 5mm thick, the fins are 1mm. The whole thing
> is quite small, as there is no point in making it larger, because the
> thermal resistance along the copper basically disconnects any more
> remote fin area. And there is a flow switch, that simply shuts down the
> power supply if the flow falls below a certain value.
>
> 20 liters of water can store enough heat to last comfortably through an
> afternoon of hamming, and overnight the bucket cools down almost to room
> temperature. To work a 48 hour contest, some sort of heat exchanger with
> fan would be needed, or the water would need to be replaced every
> several hours.
>
> The bucket has a cover on it, to keep out contamination, and keep
> moisture in.
>
> I'm using plain tap water, but my tap water comes from a well, has no
> chlorine in it, and some slimy forms of life tend to grow in it, and
> need to be flushed out from time to time.
>
>> Is it tap water through the heatsink straight to the sewer
>
> That would be dangerous! Tap water is usually colder than the room, and
> very often it will be colder than the dew point inside the room. Flow
> tap water straight from the tap to your amp, and you could easily get
> condensation on your electronics. That can cause some fireworks.
>
> Even my bucket system would pose some risk of condensation, if the
> absolute humidity in the room can go up fast, for example if you live in
> Florida, keep the room airconditioned, so that the bucket is cool, and
> then suddenly you open windows and let in the hot and humid air from
> outside. But I don't live in Florida! My house has very even
> temperature, the relative humidity is never above 70%, and that gives me
> enough safety margin against condensation.
>
> As you can see, water cooling does have some quirks.
>
> Manfred.
>
> ========================
> Visit my hobby homepage!
> http://ludens.cl
> ========================
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