At night I make a fire in the boiler and reload it once if the
>> temperature is low or if it was not a sunny day.
>> The two days in the chart were both sunny days.
>> Basically the wood burning each night will raise the temperatures in
>> 880 gallons of storage from 120 degrees to near 160 degrees.
>> On a cold night, that will take one fire started around 5 pm (after
>> sun goes
>> down) and a reload after dinner around 8 pm.
>> That will get me through the evening and night and the tanks
>> temperatures can fall back below 120 on a cold night (below 0).
>> My normal heating system kicks in when the tanks are below 120.
>> The solar side on a sunny day can raise the tanks temperature some
>> while keeping up with the heating requirement during the day.
>>
>> The two heating sources are the wood burning tanks and the solar tanks.
>> The wood burning tanks are heated by the Flex Fuel which controls the
>> process.
>> The solar tanks are heated by the solar panels and the pumps are
>> controlled by an iSolar Plus controller.
>>
>> The two heating sources supply the two hot water storage areas,
>> Radiant and DHW.
>> This process is controlled by an iSolar BX controller and pumps water
>> from either the Wood or Solar tanks to either the Radiant or DHW
>> storage when the temperature differential is over 8 degrees.
>> The Radiant storage heats the glycol for the in-floor heat in a 3000
>> sq.
>> ft. addition and is controlled by the iSolar Plus controller.
>> The DHW storage provide hot water to the 4000 sq. ft. main house and
>> also heats the glycol which is inserted into the main house boiler
>> system.
>> The extra water storage dumps are necessary because the solar system
>> by itself can only heat 460 gallons while the wood burning system can
>> easily heat 800 gallons or more.
>> Heated water is diverted through the storage dumps when the water
>> temperature is over 138 degrees.
>> That helps lower the water temperature returning to the wood burning
>> tanks and helps keep a high delta between the supply and return from
>> the Flex Fuel so it does not go into part load.
>>
>> Piping the Flex Fuel required a learning curve.
>> I did not have room for a large water storage tank and originally I
>> was not running the Flex Fuel water through enough indirect storage
>> to remove the heat fast enough.
>> Also, since the Flex Fuel is located in a shed outside the house, I
>> did not want to connect it directly to large capacity storage in case
>> of freezing issues.
>> Those problems are solved and the system seems to be running very
>> effectively.
>>
>> As far as ease of use goes, it takes me 5 minutes at most to start a
>> fire and load the wood.
>> It take about 1 minute to reload it 3 hours later.
>> I am incredibly satisfied with the way it heats the water and seems
>> to do every thing pretty automatically.
>> I originally did test the unit with the pellets and automatic feed
>> and it worked fine.
>> But for now, I have years worth of old lumber and pinion pine to
>> burn, so I have not used the pellet side.
>>
>> Designing the system and implementing it was a fun project for me and
>> I am quite happy with the results.
>> For anyone who has the wood and is fine getting their hands dirty
>> every once in a while, I would definitely recommend the Flex Fuel.
>> I would also imagine that there are not many products out there which
>> are as efficient with how much heat they get out of so little wood.