ISeeDeadBTUs said:
Recently I heard someone say (not on the Net) that with hot air systems, you need a higher VOLUME of heated water. I shall not purport to understand that, but I am curious about your experiances.
What made me think to ask is the post from a GreenWood operator who is having some trouble with his hot air system. These Refractory Mass Natural Draft unit have a very low water volume. The GW100 claims to have only 8 gals.
I know nothing about pump size/speed nor W2A HX so I am hoping some will chime in with their findings and some ideas for the member in duress.
I think the problem is most coils or ready to install fan coils are sized to work with a fossil boiler that operates say 140 - 180. With a very small water capacity.
On & off a lot, but thats ok, they were built for that & the fuel source suits this constant on/off cycle.
Wood burners want a bigger usable temp range say 100 - 200. As well as a lot more water capacity (storage). So we can fire less & rest/enjoy more. :coolsmile:
So when we go looking for coils we need to be thinking bigger, both in coil size & fan CFM.
Bigger coils have more btus available to use. Bigger faster fans (more cfm) can extract more btus out of whatever coil is available.
With my own set up, once I knew what the fossil burner chart said I needed for a fan coil size & cfm of fan to push through it, I looked at what I wanted to use for water temp minimum 100. That was nowhere to be seen on the fossil burner chart.
Then I went looking for a fan coil & fan cfm that would deliver the btus at that minimum 100 temp. I found that I almost needed to double the size & cfm that the fossil burner chart said I would need for a fan coil with water at 140-180.
So long story short I bought the second largest residential model of fan coil that they made, according to the fossil burner chart this was way too big. I am glad I stuck it out & went with the bigger fan coil. Now I have a usable water temp range of 100-200. That equals less firing for me & more rest/enjoy time. Win win. Love those. :coolsmile:
Only one downside so far, the boss likes her showers/baths hot enough to cook a lobster in, that is not easy to do with lower water temps, so I may have to move the bottom temp up to keep the peace, as well as keep my head attached to my body


:bug: House temp is one thing her bath/shower temp is a totally different matter :red: . I kind of like my head attached to my body, so I best do all I can to keep it that way. ;-)
One last thought, this GreenWood owner needs to give serious consideration to what Heaterman & others remind us of.....storage......no way is 8 gallons going to get it done with a wood burner. Think minimum 1000 gallons for starters, with plans to expand that in the future. :roll: Nobody wants their wood burner to cycle on/off like a fossil burner, right? :-S