Colder Climates (Germany)
have you had any experience on how much the whole processing heats up the container? I wonder if I would try this design in Germany with cold winters and everything if I needed additional power to heat up the whole thing, make better insulation and everything?
Thanks in advance!
Hi. It doesn't heat up much at all. This is because you're using only 'brown' (ie. woody, slow decomposition) materials in the tank. If you used green material then you'd get a thermophilic composting process and it would get way too hot and kill the worms. Use woody material only and there's only a minimal thermophilic response.
I don't think you'd need to heat the tank. Although the worms prefer temperatures around 18-20°C, they will still survive at 5°C. Their activity just gets slower. If the tank is very well insulated, then it should maintain temperatures around the subsurface year-round norm for where you are. Wood itself is an insulator as well.
That is an interesting question for me too. I live in Sweden and I've been wondering how to keep the toilet going in winter. The worms will obviously survive at 5 degrees, but they won't be very active, no? Doesn't that mean the tank gets loaded but no decomposition takes place, meaning it will get too full? And once it gets warm again, can the worms quickly enough deal with the material collected over the winter? My guess is it would need very decent insulation.
Anyone here tried this in a colder climate?
Where in Sweden are you? From a quick internet search, I found the average ground temperature in Sweden varies between 11°C in the south and 2°C in the north and that one fifth of Swedish homes use ground source heat pump (GSHP) systems. If you're in a position to install the worm tank in an environment (a basement?) where it's possible to keep the worms warmer than they might be outside, then this would obviously help the efficiency of the ecosystem in winter. Otherwise yes, they will slow down the decomposition rate. To what extent depends on how many people are using the system and how your individual microclimate impacts temperatures in the tank. There are probably any number of possible solutions to the problem depending on context, but a bit of lateral thinking may provide the answer? For instance, if the tank is well insulated, perhaps you could consider adding a hot water feed to your toilet cistern so the flushing water is heated to say 28℃?
I'm in Southern Sweden and it tends to stay rather warm. We had a week of -20 this winter, otherwise it mostly hovered around -5 to 0.
Hot water is a very simple yet brilliant idea! I was actually thinking of using the worm tank for all of the house's water, which means that most of it will be warm, even in winter, as it would be coming from kitchen sink and shower. So that should work. So excited to try!