Torspå40 automated outdoor wood furnace

Torspå40 outdoor wood furnace

Torspå40 is an outdoor wood furnace. Unlike classic furnaces, Torspå40 uses woodchips or wood pellets as fuel instead of cordwood. This means that it is fully automated, and you just need to fill the silo from time to time instead of going daily or more to fill the furnace.

Torspå40 has been designed to take the place of an outdoor wood furnace. It is equipped with a hydronic boiler that is simply connected to a hot-water heat loop that can include one or several buildings. If you already have an exterior wood furnace, you can simply replace it with Torspå40 and use your existing setup.

Torspå40 is an integrated solution that includes:
– A Säätötuli Strong 920 biomass silo
– A 40kW / 136,000 BTU/hr Säätötuli biomass burner
– An unpressurised hot-water Veto boiler
– A C110 automation control box by Säätötuli
– A skid-like frame with holes for forklift
– All plumbing work around boiler ready, just to connect the inlet and outlet to the heat network
– A protective cabin for the boiler with fire-resistant sandwich-panel cladding and roof
– An insulated chimney

Interior of Torspå40 outdoor boiler

Circulator pump for the heat network is not included. Säätötuli can include the pump as an option and help you calculate the pump you will need.

The Veto boiler is a Finnish-made boiler, specifically developed to use a biomass burner. It is built according to PED. That means that it is built to the strictest European boiler standards, guaranteeing its quality. It can however not be pressurised in Canada except in the few Provinces or Territories where the regulations accept PED. The boiler can also be equipped with an optional firewood grate, allowing use of cordwood if your biomass delivery is late for example.

Torspå40 biomass burner in action

Säätötuli’s burner ensure a complete and clean combustion without visible smoke nor any smells.

The Säätötuli Strong has a 920-liter fuel silo. It is enough to run the unit between 24 and 48-hours at full output with woodchips, or about a week with pellets. Outside of the coldest days of the winter, you can expect it to last between 3 and 15-days depending on your needs and the outside temperature. Säätötuli has also several other types of biomass silos as an option.

The C110 automation control is manufactured by Säätötuli in St. Hyacinthe, QC. It has a PLC control with 2-line digital display. Display can be in English or French. All the electrical works are made ready at the factory, and you will just have to plug a washing-machine type plug to your 240V/60Hz power outlet.

Torspå40’s integrated thermostat regulates the burner output. Once the boiler is at the desired temperature, the burner will automatically go on idle. In idle mode, it will simply keep a small quantity of embers in the burner. This is done by inserting a small amount of fuel every 10-minutes and blowing on it a few seconds. That way the burner keeps hot and is ready to get back to full output in a timely manner as soon as there is a need for heat.

It is highly recommended to avoid using the boiler thermostat to regulate the temperature of the water going in the heating loop. A boiler that will get cold and hot several times a day will have its lifetime reduced because of metal fatigue and corrosion. Metal will expand or retract depending on the temperature and having the boiler change temperature frequently will end up with microscopic cracks that will expand at every cycle. Sending cold water in the boiler will induce condensation in the flue gases and corrode the heat-exchanger.

We recommend installing a mixing loop to control the temperature of the water going to the heating loop. That way the boiler will always be at its maximum temperature and the mixing loop will mix some cold water from the return loop to obtain the desired temperature in the heating network. Torspå40 can be fitted optionally with this system when the delivery includes the main pump. Säätötuli can give you some tips on the way to optimize your heating network when installing a Torspå40 to your system.

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If you have an existing outdoor wood furnace that you would like to convert to use woodchips or pellets, you can also check out our retrofit solutions.