The Homebrew fountain thread  reminded me of a project I have on the back 
burner....


I am considering building a cold water reservoir to connect to the filtered 
water dispenser I have installed on my kitchen sink. What I would like to do 
is place a hyper-insulated water container between the filter and the 
faucet. This container would have two ports and an internal baffle system to 
mix up the water when water is flowing.

One of the ports would connect to both the incoming water line and the 
output of a small pump.

The other port would connect to the faucet and the input of the pump.

In the pump loop would be a water block, much like that used for water 
cooled computer systems, which would be cooled by a peltier device, the hot 
side of which would by sinked by a heatsink and fan.

And of course it will all be controlled by a PIC :-)

All of the pieces have come together very nicely except one. I am having 
trouble finding a water pump that:

1: Can move moderate volumes,

2: At very low head,

3: Quietly,

4: Cheaply,

5: and is safe for potable water (drinking water if any non-English speakers 
don't know the word)

--------------------------

An alternative idea I had was not using a pump at all, but rather thermally 
connecting the reservoir directly to the peltier. I see two issues:

1: Much more difficult to effectively hyperinsulate the reservoir (I 
considered moving baffles that would cover the whole pelter/sink/fan 
assembly with insulation when not active)

2: A problem keeping the water well mixed to spread the cool.

Primary goals:

1: Reasonable implementation cost

2: Low operating cost

3: Quiet

4: Modest short term demand capability. Say 2 L immediately at ambient - 15 
degrees C or so, a two or three hour recovery time is fine.

5: Fun doing it :-)

Any good alternatives or ideas?

Bob Ammerman 

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