The used propane tanks showing in this video are stacked and used for water storage with a Vedolux 50 natural draft boiler. The video below shows the lighting sequence. There is a draft booster installed in the flue but for this lighting it was not used. The draft booster can be used during lighting if there is a weather system creating a back pressure or otherwise poor draft. The tanks will be fully insulated after the system has been operated for a bit.
With two 500 gallon tanks the 1000 gallons of total water volume is a good fit for the output of the natural draft Vedolux 50. The storage tanks are propane tanks that have been taken from service by the gas company. They are steam cleaned and modifications like ports and legs are added where necessary. The stacked tanks have very good stratification. The radiant floors in the new addition are heated exclusively from the wood system and a primary loop runs over to the oil boiler and becomes the heat source if the tank temperature exceeds 140 degrees.
This natural draft boiler offers downdraft gasification burning without an integrated fan. Because the stack temperatures with the natural draft boilers offered by Varmebaronen need to be about 50-100 degrees higher than their suction fan counterparts the efficiency level for the natural draft boiler is 5-10% lower than the suction fan models. The higher stack temperature is needed to maintain the needed air velocity.
This system is heating an old farmhouse with a new addition in central PA.