Tuesday, September 16, 2014


Our summer visit to Aspö coincided with quite the Swedish heat wave. It got me thinking about heat pumps, or in Swedish, värmepump.

Why on earth would I think about heating the house during a heat wave, you might ask? That's a good question, and the answer is pretty simple.

Air-conditioners or furnaces use energy to create hot or cold air. A heat pump simply transfers heat from one source to another, and the direction is reversable. This means a heat pump can cool a house just as easily as it warms.

Värmepumps are installed in Sweden not for their cooling, but for their energy efficiency. Transferring heat, rather than creating it, uses far less energy. Heating our house in cold weather is pretty pricy with a Dyson and radiators. (Doesn't that sound like a 50's rock band- "Dyson and the Radiators"? But I digress.)

I posted recently about how my March visit showed my using about 65 kilowatts per day to heat the house on a cold day. I believe a heat pump would do that job at significantly less energy cost. It would have the added bonus of providing a bit of cool air on hot days, if needed.

Our house is pretty small, 62 square meters (670 square feet), so even the smallest unit would do the trick for us, at a price of around 8000 kronor. Olle is well versed on these units and gave me lots of advice about how to choose and install them. Polarpumpen.se has a wide variety of värmepumps available.

Another fun trick is attaching it to the cell phone network. I could then use an app on my iPhone to monitor and adjust the temperature remotely. It would be great to arrive at a nice warm house, or to ensure things don't freeze solid during a cold snap. Plus, it appeals to the nerd in me; I love controlling things with my iPhone!

Here in the US, these are called "split unit" or "ductless" heat pumps. The compressor is installed outside, and a tube is run along the outside of house to the head unit which is mounted to the wall inside. The photo above shows the two pieces.

I set aside space for a heat pump when I designed the house, and in fact, also put in the electrical wiring, too. So physically installing the unit should be pretty simple.

The complication comes with charging and pressurizing the unit. Specialist tools and skills are needed to get it connected and working. Polarpumpen quotes installation costs of 3000-5000kr on their website, although I assume the archipelago isn't in their normal price list.

I thought perhaps I could buy and install the unit myself, and only have the specialist come out on a short trip to charge it up and test it. That should be cheaper, although I'll have to ask around and get some concrete advice and prices.

Stay tuned for more on this subject in the coming months!

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