How To Make A Hybrid Heat Exchanger

Feb. 23, 2014

Materials used in a hybrid heat exchanger


Here is the new video on how to make a hybrid heat exchanger using copper and plastic. The heat exchanger similar in design to the first heat exchanger. The difference being that I used copper fittings and pipe to make the outer chamber in the first build.

By using PVC fittings and pipe in the new heat exchanger build I was able to reduce the cost of building by 85%.You still need to use copper as the material for the heat transfer material. Plastic is a great insulator but is a horrible heat conductor.

All copper built heat exchanger
Picture of an all copper heat exchanger


If you plan on having fluids run through the exchanger that are above 160°F, do not bother using plastic. At this point you need to do an ALL copper build.

Materials used for this build

2- 2″PVC Tee

2- 2″Plastic/cast x 1-1/2″ copper MJ coupling

2 feet 2″ PVC pipe

2.5 feet 1-1/2″ type L copper (blue writing)


You will need to purchase PVC purple primer and schedule 40 glue. BOTH are needed to properly glue PVC fittings and pipe.

11 thoughts on “How To Make A Hybrid Heat Exchanger

  1. Ken R

    Thanks for the great info.

    I need to do this for potable water at very low pressure (under 4 PSI). As you mentioned, I need potable MJ couplings, but I’m having trouble finding them. Any source you know of?


  2. Peter

    Can these be adapted to a cold water 3/4 pipe?

    • Yes very easily. Just use reducing bushings or couplings.

  3. Chris

    Maybe a dumb question, but which pip carries the drain water, copper or plastic. If copper, then what pressure can pvc handle?

  4. Mike Bulpin

    Perfect timing. Looking to heat hot tub from outdoor boiler. If i reduce my inside copper to 3/4 should i also reduce the outer PVC?
    I see the gap between the 2 is very small. Is there a reason for that?
    I do know you said it would be in the next video.

  5. What is the procedure making this het exchanger?

  6. Can this one be used as a pasturing machine?

  7. Do u first heat the liquid and the pump the system ie plate heat exchanger?

  8. Anonymous

    Pode ser usado para resfriar mosto?

  9. Brian

    Hey Rob, what is the heat transfer like per foot?
    Also you mentioned ganging them but I don’t see any article or video re this.
    Thanks for the good how to video.
    I am planning to install a heat exchanger on the side of my DHW tank to pull some heat for my garage to keep it from freezing. Plan on using a car radiator and circulating pump on the garage loop. Fan behind rad.

  10. Lars

    Hi Rob,
    I have a Thermal (almost like a reverse refrigerator) heated water tank which stores hot consumption water (shower, dishwashing, drinking – if you like to drink hot water) at 55 degrees celsius.
    The compressor of the system (which is the only element that gets outside energy and heats up to 300 l water use abut 600 W per hour it is running) run about 5 hours a day, so consume on average 3 KWh power per day.
    I want to add the ability to heat my house from the energy source that this hot water is, and know that I probably would need a heat exchanger of some kind.
    As there from the outset is no out and in for heating on my tank, I wondered if it would be possible to make a heat exchanger which is mounted directly on the water tank (e.g. by using strong magnets) and then get the “heat source” from the contact with the 55 degrees celsius warm water tank?
    The idea is to bend the cobber tube with the water to be heated so that it is “flux” with the water tank, expecting the heat from the tank to be transferred to the cobber tube or places, thereby heating the water running in the cobber tube.
    I know I would probably have to add a flow pump (looking at Grundfos UPM3 Hybrid) to ensure sufficient circulation in the heating system, but the power consumption from that is minimal!
    Do you think this would be possible?

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