My family just bought a house in southern Vermont. For many reasons, we wound up buying a house on the northern slope of a mountain (we're in the Green Mountain National Forest). I plan on putting in a large greenhouse built on passive solar power designs, with a climate battery.

On the north side of the north wall I'll be building rooms for a kitchen, aquaculture, an office, and more. I'll have rocket mass heaters to heat this part of the building. These rooms will help insulate the northern side.

Because of the location, I'm questioning how much sun I'll actually get. This IS Vermont, and it can get very cold in the winter, and I'll have to deal with cloudy days as well. I'm considering using a rocket mass heater to recharge the climate battery.

Does anyone have any experience charging a climate battery with another heat source?

@subarctic does alot of solar at his place and might be able to help you.

Are you going to heat the greenhouse with the rocket mass heater? If so, why bother with the climate battery?

StarTyger said: Because of the location, I'm questioning how much sun I'll actually get. This IS Vermont, and it can get very cold in the winter, and I'll have to deal with cloudy days as well. I'm considering using a rocket mass heater to recharge the climate battery.

Does anyone have any experience charging a climate battery with another heat source?

By climate battery I'm guessing you mean the thermal mass: heat rather than electricity. It gets cold here, at 7800 ft. in the Rockies, but we do get bright sun. Designing a greenhouse from scratch to suit the local conditions, I use a salvage residential flat-plate collector, on a PEX loop charged with 50% glycol. Note the steep angle, set for mid-winter sun. The 20W PV panel drives a DC pump that circulates the loop, at a rate according to the intensity of the sunlight.



The roof is 6-wall poly (R 3.8) and the sides are 3-wall. For severe cold (-10°F and below) I light a small propane heater and turn on a small fan for the night.

For more details, see this thread.
The thread "Low-tech Solar Radiant Heat" in Greenhouses forum

A climate battery is a ground to air heat transfer system using the sun and the Earth as the solar mass.

I am at parallel 39N, you are at 44N. The winter sun stays way south, my north facing windows don't get any light and I'm on the top of a hill. I question weather it will work at all that far north on a north slope in winter.

We're at about 42°N and I think you're about 43°N or so. If you're on a northfacing slope, does the mountain block your winter sun? How many hours of direct sun are you seeing now? We're getting about 9 hours.

Some data: last night got down to 10°F. Day temp was about 40°F. Clear and sunny.

Floor/thermal mass temp was 55°F. At noon, the glycol solution inflow was about 135°F. The 400 gal. heatsink under the floor reached 104°F, with the circulation pump off. I turned it on. By tomorrow morning, the thermal mass will reach 60°F or so.

When the difference between the floor temp and heatsink is 15° or less, the pump stays off. Not enough heat transfer to justify the electricity for pumping.