Thermosiphon Butterflies

The thermosiphon has been proving itself this whole Winter. It’s quickly becoming one of the best features of our house design and it’s not hard to imagine why. 100% passive & efficient air circulation taking heat from the stove to every nook and cranny of the house. No power, no fan, no duct.

As a bonus, it animates decorative butterflies. Now I don’t really care about the butterflies; I only like seeing them as an indicator of the free work our house is giving us. They’re a great analog anemometer.

Thermosiphon a success

I built the house with 2 flights of stairs, pretty overkill for a 1200sqft house and I’ve often gotten this feedback. There’s a couple of reasons I went through the extra trouble and extra wasted space.

  1. I like 2 ways out the first floor for safety. You never know when the government ninjas will come get you, but more seriously: fire safety. You know, for when the government ninjas set the house on fire.
  2. It provides the opportunity for a thermosiphon. Hot air from 1 stove rises up 1 side, cools down, and circulates back down the other.

With lower temperatures upon us, we have finally tested it and it works beautifully. I was worried that practice and theory would diverge, such was not the case and so we heated the whole house for the first time with one stove and awesome passive circulation keeping every nook and cranny warm.

Standing at a choking point such as a doorway, you can clearly feel the air moving. I’m super happy this is working.

Candle test

Now the one thing we still need to get used to is how much more wood we’re burning. We more than doubled our living space going from the tiny 450sqft to the more appropriate 1185sqft, circulate all you want it takes a lot more wood to heat it all up :).

I’ll be using thermosiphons to heat water too at some point.