I built this earthberm house three y/a. Heat is via wood burning gasification furnace with in-slab hydronics.
The furnace is computer controlled via a conventional thermostat.....The firebox smolders wood under hypoxic conditions until the thermostat switches "on." Then a fan blows a little air (oxygen) in and the H2/CH3 + O2 burns in a nice blue flame down in the lower combustion chamber, heating the water....There's an internal thermostat that regulates a pump, sending the heated water to a holding tank, and an external pump that circulates the hot water thru the house.
The furnace is continually heating the water even when the furnace is "off" and the furnace pump periodically sends heated water to the tank based on computer settings....The general circulation pump, however, only circulates hot water thru the house when the thermostat is switched "on."
The Problem-- the house is so well insulated that once the set temp is reached and the thermostat switches "off" it takes 4 hrs or more for the ambient temp to fall enough (1degF) to switch the thermostat back "on."...In that extended period, the concrete slab cools off enough that it takes a good deal of wood to bring that large thermal mass back up.....
...Even tho the furnace is smoldering away making a good deal of heat continually, it remans tied up in the tank, not being circulated....I've found this week that by manually messing with the thermostat every hour, I can turn the furnace on for 10 or 15 minutes, keep the slab warm and the house really warm while burning 25% less wood.
Any ideas on how to automate this process electrically/electronically?
The furnace is computer controlled via a conventional thermostat.....The firebox smolders wood under hypoxic conditions until the thermostat switches "on." Then a fan blows a little air (oxygen) in and the H2/CH3 + O2 burns in a nice blue flame down in the lower combustion chamber, heating the water....There's an internal thermostat that regulates a pump, sending the heated water to a holding tank, and an external pump that circulates the hot water thru the house.
The furnace is continually heating the water even when the furnace is "off" and the furnace pump periodically sends heated water to the tank based on computer settings....The general circulation pump, however, only circulates hot water thru the house when the thermostat is switched "on."
The Problem-- the house is so well insulated that once the set temp is reached and the thermostat switches "off" it takes 4 hrs or more for the ambient temp to fall enough (1degF) to switch the thermostat back "on."...In that extended period, the concrete slab cools off enough that it takes a good deal of wood to bring that large thermal mass back up.....
...Even tho the furnace is smoldering away making a good deal of heat continually, it remans tied up in the tank, not being circulated....I've found this week that by manually messing with the thermostat every hour, I can turn the furnace on for 10 or 15 minutes, keep the slab warm and the house really warm while burning 25% less wood.
Any ideas on how to automate this process electrically/electronically?