If your gasifier or wood burner is tied into your forced air system...

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GS7

Member
Dec 14, 2012
180
Connecticut
I'm wondering what you have your minimum temperature set at before your forced air fan kicks on? What have you found to be the most beneficial minimum temperature?
 
Minimum temp set at? The fan should be controlled by room temperature (thermostat), not water temperature. I assume you're curious to know the minimum temperature the coil will be effective at? If that's your question, my run-of-the-mill heat exchanger will operate perfectly down to about 140 degrees. I start to notice extended fan run times between 130-140. Below 130 on a "pretty cold" day in Michigan and my furnace fan will pretty much run non-stop.

With a better coil design you could easily use water temps down to 120 or so I believe. If I had to do it all over again I'd spring for a better coil, personally. Mine was off the shelf and sized to match the load and plenum but is far from optimized.
 
Yes you're right I was thinking of the minimum coil temp. (told you guys it's amazing I pulled off this installation because this isn't my background lol). Thanks for the feedback
 
Our HX was sized to fit our plenum and thickness designed for a 30*F temp drop. It performs as designed and gives about the same results as Stee quotes, so Stees must be pretty good. At about 125-130*F the rooms at the end of the longest duct runs get cool so we try to keep supply temp above 130.
 
Mine isn't set up ideally. I have 2 stats, one controls the fan, the other controls the heat on the furnace. I've got the one for the furnace set low, in case of emergency.
 
I have an aqua-stat my coil. If the water is not 130 3 minutes after thermostat calls for heat. The aqua-stat stops the pump and the lp furnace ignites and runs as normal.

I try to not let my tank go much below 140 because my lines in garage aren't insulated very well. it provides a little heat for the garage but lowers the water temp by the time it gets to coil in basement.

gg
 
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I have my water temperature set at 150 off and 130 on. I have two thermostats in the house. One for the wood stove that turns the circulating pump on and the furnace fan set at 70. Another that runs my heat pump as normal set at 66.
This works best for my set up, but my set up is all home made.
 
Thermostat turns on circulator pump for the zone (I have three fan coils and three radiant floor zones). Fan turns on by aquastat on return line of fan coil. Fan on at 155 and off at 145. I had the aquastat set lower but found fan ran for very long after call for heat because of residual heat in line. Normal system temp is 180 with gasifier running.
 
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