I finally got my first taste of wood generated heat (via forced air HX) last week. It took me way too long to assemble the primary manifold near boiler, secondary manifold in basement, and get the HX properly installed in the plenum. Purging the air out of 700' of underground PEX and fixing a few small black iron leaks took a few days of trial and error as well. Good news it is done and puts out heat. I will be able to carrover almost all of my wood supply to next year which should give me a year cushion to be able to maintain a supply of well seasoned wood. The EKO really loves some dry walnut & red elm that I've been giving it. Dry wood is really the key it seems.
I still haven't found the best way tie my current thermostat into the wood heating solution. I have been just shutting off the heat pump completely and letting fan run continuous which requires me to turn it off when it gets too hot. At night I let it run in heat pump mode so the hot water HX is further warming the air going out even more allowing it to run less to keep house warm. I did also open the breaker to the heat pump itself one night and that seemed to work fine too until the wood ran out and the water got cold.
I know at a minimum I need an aquastat or snap disc sensor on the secondary manifold coming into the basement. I suppose this could then be wired in series to a 2nd thermostat. So when the water is hot enough AND my 2nd thermostat calls for heat I could use the thermostat output to power a relay tied directly to the air handler blower and HX circulator. This output of this relay would probably drive the existing blower relay at whatever the coil voltage is (haven't checked that yet). The NC(normally closed) side of my new relay would be the existing feed to the blower relay while the NO(normally open) side would come from the output of my 2nd thermostat. I have a LUV baseboard 120v thermostat (says not for anything other than baseboard electric) with a simple dial that I want to attempt to try in this configuration. It should work fine since I am only using it to trigger the blower & circ and not doing anything with the existing Lenox wiring. I would set my existing thermostat 3-4 degrees lower than the hot water thermostat and I doubt the heat pump thermo would ever run when the water is hot enough at the aquastat. Even if it did it should not hurt the existing Lenox equipment the way I am hooking it up. Not sure how the built in humidifier works but there may be a way to make that function as well when the wood heat thermo is operating too. Would need to check if the existing thermostat wire has any free wires too.
Now while I am pretty sure the above paragraoh should work I also wondering if I can find a new thermostat that will do everything in one package without costing a bundle. I've seen posts where someone was going to try a multistage thermostat (like Honeywell 8320 3H/2C) using the wood option as one of the stages. Reading the installation manuals I'm not so sure this will work in a wood boiler setup. The Honeywell instructions indicate that if you bump it up 10 degrees it will immediately fire the 2nd stage rather than waiting a specified amount of time like I'm envisioning it should. Hopefully next winter I will have some Arduino monitoring mechanisms that may provide for this directly but I need to get a failsafe approach working now. Anyone see a problem with my plan or have you had sucess using a multistage thermostat to do everything. The geek in me thinks it would be cool to simulate one of the cool $300-400 thermos (outdoor temp, humidity, room temps, boiler temps, stack temps,storage, etc.) on a web page that could be accessed from anywhere (home, work, vacation, easy chair using my blackberry). That probably won't happen anytime soon however.
I still haven't found the best way tie my current thermostat into the wood heating solution. I have been just shutting off the heat pump completely and letting fan run continuous which requires me to turn it off when it gets too hot. At night I let it run in heat pump mode so the hot water HX is further warming the air going out even more allowing it to run less to keep house warm. I did also open the breaker to the heat pump itself one night and that seemed to work fine too until the wood ran out and the water got cold.
I know at a minimum I need an aquastat or snap disc sensor on the secondary manifold coming into the basement. I suppose this could then be wired in series to a 2nd thermostat. So when the water is hot enough AND my 2nd thermostat calls for heat I could use the thermostat output to power a relay tied directly to the air handler blower and HX circulator. This output of this relay would probably drive the existing blower relay at whatever the coil voltage is (haven't checked that yet). The NC(normally closed) side of my new relay would be the existing feed to the blower relay while the NO(normally open) side would come from the output of my 2nd thermostat. I have a LUV baseboard 120v thermostat (says not for anything other than baseboard electric) with a simple dial that I want to attempt to try in this configuration. It should work fine since I am only using it to trigger the blower & circ and not doing anything with the existing Lenox wiring. I would set my existing thermostat 3-4 degrees lower than the hot water thermostat and I doubt the heat pump thermo would ever run when the water is hot enough at the aquastat. Even if it did it should not hurt the existing Lenox equipment the way I am hooking it up. Not sure how the built in humidifier works but there may be a way to make that function as well when the wood heat thermo is operating too. Would need to check if the existing thermostat wire has any free wires too.
Now while I am pretty sure the above paragraoh should work I also wondering if I can find a new thermostat that will do everything in one package without costing a bundle. I've seen posts where someone was going to try a multistage thermostat (like Honeywell 8320 3H/2C) using the wood option as one of the stages. Reading the installation manuals I'm not so sure this will work in a wood boiler setup. The Honeywell instructions indicate that if you bump it up 10 degrees it will immediately fire the 2nd stage rather than waiting a specified amount of time like I'm envisioning it should. Hopefully next winter I will have some Arduino monitoring mechanisms that may provide for this directly but I need to get a failsafe approach working now. Anyone see a problem with my plan or have you had sucess using a multistage thermostat to do everything. The geek in me thinks it would be cool to simulate one of the cool $300-400 thermos (outdoor temp, humidity, room temps, boiler temps, stack temps,storage, etc.) on a web page that could be accessed from anywhere (home, work, vacation, easy chair using my blackberry). That probably won't happen anytime soon however.