Portable air-source heatpump teardown

This video made me realize that heat pumps are very “hackable” and open to DIY. Even out of the box, this particular unit is super impressive. It has a COP of 2-3 (i.e., it is 200-300% efficient) for heating, 4-5 for cooling. I bought one online for ~$1000USD. It showed up on my porch a couple of days later. I plugged it into a 110V outlet, hooked up a dual hose duct adapter to a window, and my gas furnace hasn’t fired up since it’s been plugged (we’re currently in the middle of a cold Canadian winter).

Anyone actively working in this space?


This $1000 heat pump could not keep up with the demand <-10C. It is still supplementing the gas furnace for now, but I’m not ready to cut off my gas line yet folks :wink:

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That’s fantastic! Congratulations. Where in Canada are you?


Very cool – is anyone else interested in working on a completely OS / able to be manufactured with AM heat pump?

Work we have done shows HPs are already economically viable in northern US/Canada if solar PV powers them - Energies | Free Full-Text | Economics of Grid-Tied Solar Photovoltaic Systems Coupled to Heat Pumps: The Case of Northern Climates of the U.S. and Canada

It would be nice to have a completely OS solution to green electrification of heating.


I’m in Kitchener-Waterloo (1hr West of Toronto).

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Yes! I am very much into this idea. I was hoping to organize a hackathon/work week around Earth Day (April 20th). This would make an awesome theme…

Look forward to reading your study. I’m also bullish on solar PV/thermal + heat pump + thermal storage.

And if you want to get really crazy, throw in a 15kW ($1,000) portable steam generator that could power your neighborhood.

:sun_with_face: :electric_plug: :fuelpump: :muscle::house: :house: :house:

I’ve put together some slides/concepts for a $1k heat pump to get ideas flowing. Would love to collaborate with anyone interested.


LOL. I know where it is, I went to David Cheriton.


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Yes! I want that! I’m currently on a journey to build a fully off-grid house using aircrete dome (like these https://www.domegaia.com/), specifically with the goal of lowering housing costs and avoiding complex regulatory requirements so homes can be inexpensive and we can live in the ‘Star Trek future we deserve’ (quote from @sudokita ).

I’ve been thinking actually about corn stoves, which are easy to manage, provide consistent heat, are inexpensive and while they require a little bit of manual work it’s quite minimal. However, this looks really potentially amazing if you could combine solar gain with heat pumps and (like you said Joshua) actual solar PV.

I’m definitely interested if there’s a build day, I’d love to learn more!

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There’s been some work on daytime passive radiative cooling (DPRC) below ambient, and someone has applied this to cooling the A/C radiator. This seems to be the best use of DPRC at the moment but I can’t find the paper right now. However the approach does seem amenable to small scale experimentation, as evidenced here.


Yes OSH heat pumps are interesting to me. @jpearce can you suggest a place we could start gathering research/designs? Is Appropedia good for this?

Someone has been working on an Arduino controller

Some FOSS monitoring stuff seems to already exist: https://heatpumpmonitor.org/


Brilliant! - Yes I started it here - and started loading it up https://www.appropedia.org/Pumps_for_Peace


Would you consider including absorption cycle devices? Usually this is used for cooling but they can also work backwards for heating. The Icyball used ammonia/water, but it’s also possible to use something as innocuous as calcium chloride and water or alcohol.


@ryanfobel @Jsmleete and @Albercook met on this and had some really exciting ideas about how to enable groups to meaningful contribute and benchmark advances in an open way.

Hoping we can get some notes here on the forum for that, really love this idea!

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I’m interested in this topic, but am not in academia (not sure how important that is).

Not important at all - please dive in and start editing! - https://www.appropedia.org/Pumps_for_Peace

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I took a bit of a look at refrigerants, Is CO2 the best option here?

We might want to do a comparison table - pro con, material compatibility, pressure/temp performance and cost with refs - as that will determine a lot about the design and there will likely be different optimums depending on where you live and what materials you have ready access to.

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Yeah that probably makes sense, although the toxic/flammable ones are probably best avoided?

I’m going to get a few quotes from professional Heatpump designers to see what they’d charge for designing such a system. Perhaps a crowdfunder for a functional V1 would be viable? We could then iterate on a functional system.

I’ll see if anyone responds to the below.

Hi I’m interested in the concept of open-source domestic CO2 heat pumps: https://www.appropedia.org/Pumps_for_Peace

These would be controlled by the GitHub - openhp/HeatPumpController: The Valden Heat Pump controller is a platform to precisely control heat pumps controller.

I’m interested to get some quotes for design work for heat pumps around the 15KW range.

Would you have the skills to design a 15Kw CO2 heat pump based around the Valden controller?

The idea would be to get a quote for the design work, run a crowdfunder to raise the funds, get the design done and then release the documentation under a creative commons attribution license.

Any manufacturer would then be free to make or improve the design.

Would you be interested in providing an indicative quote for this work?


I also had a look for opensource compressor designs but couldn’t find anything obvious.