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small chiller/heater for radiant bed

$700 is not a lot, so this is what I would do:

Buy a small electric hot water heater (1500 W point of use type), with an expansion tank, circulator and fittings. You can get all this for about $300. (Heater is about $150, circulator about $80, expansion tank -Watts #5- runs about $25, plus valves and fittings.)

Set up your Pex-Al-Pex or regular O2-barrier PEX as you need to (too much to get into here). If you can get your heater with a rheostat variable controller, even better.

That is your heat.

Cooling in my estimation is not possible using machinery in that price range. (If money were no option, a nice Filtrene unit at $6,000 would be ideal :)

For cooling, I would use the same heater/hydronic setup but instead of using the heating element, bleed in/drain off domestic water to maintain temperature. A good thermostatic bulb valve can maintain temperature. Key to me would be to keep the water "cool not cold" above the room dewpoint to avoid sweating. Provided of course that this meets your temperature criteria where it counts.

This will waste water, but the trade-off is unaffordable first cost and energy cost associated with that.

My $0.02



  • Tom Lancaster
    Tom Lancaster Member Posts: 1
    small chiller /heater

    I'm trying to build an massage table for a group of handicap people. I'm a senior at umass lowell and I'm looking to do radiant cooling and heating (W/ vibration) on a leather table. The main problem is finding a small unit to cool/ heat the water(under $700). Thank you for your time everyone.
  • Empire_2
    Empire_2 Member Posts: 2,343
    One thing I might ad

    Vibration and any inter connecting piping, be it flexible or the like do not mix. You are asking for a leak. I am sure someone else might may be able to point you in the right direction,...Sorry.

    My .02

    Mike T.
  • Eugene Silberstein 3
    Eugene Silberstein 3 Member Posts: 1,380
    How Long...

    How long would the "cooling" sessions be?

    I am toying with an idea similar to the method used to make ice cream, believe it or not.
  • Brad White_9
    Brad White_9 Member Posts: 2,440
    So, Eugene,

    Are you thinking a foot-crank bicycle arrangement, rock-salt brine solution, powered by the person on the table? You devil you!

    That is almost... Swiss.

  • Eugene Silberstein 3
    Eugene Silberstein 3 Member Posts: 1,380

    No foot crank.... but a rock salt brine yes...

    Kind of like the eutectic plates used on truck refrigeration systems.
This discussion has been closed.