Hotblast 1557 "Build" Thread

[matt701]

After 3 years of using my Hotblast and messing around with the blowers, ducting, different limit switches ect..this is my final solution. When I had the original blowers installed, it wouldn't even think about pushing the air through my ducts at all so I ran it into my return ducting which only leads to 2 big vents in the middle of the house. I was essentially heating the middle of the house to 80 so the bedrooms would be warm enough with the doors always open. The second year, I bought a big 1200 CFM blower and took the small blowers off the back and stuck the new blower on the side which greatly helped airflow, but I still couldn't push the air through my ducts very efficiently, so kept it hooked to my return. This year, I talked to Laynes from this forum about his setup and then drew up what I wanted to do and asked some friends to help me install it. RLS Heating in Upstate NY made all the ducting and is helping with the install. I'm heating a raised ranch, approx 3,700 sq ft including the basement and am getting great airflow out of all 17 vents in the house through a duct trunk thats about 55 ft long. We still have to hook the return up to the propane furnace, I'll post more pics when it's all done.

 

[smokinj]

i know what you mean i am running 100 ft got my cfm up to 1900 "thats a great looking install"

 

[jakepursell]

did you hook the supply from the gas furnace to the return on the wood furnace?ive never seen it done like thaT IM INSTALLING A HARMAN add on furnace i wasnt going to install it like that please explain you can read my set up in the boiler room on the second page i described what im doing if you can look at that i would appreciate your input.thanks

 

[matt701]

I read your post and I think you are hooking 2 furnaces up, with each having their own return and supply trunk sharing the rest of the ducting. I thought about that, but I didn't want to use dampers at all. If one furnace comes on, it could push the air into the other furnace unless you had a damper seperating them. I have one return, which comes from the living area, into the propane furnace. The supply from the propane furnace into the side of the wood furnace (We had to cut a big hole) and passes by the heat exchanger of the wood furnace and then up from the wood furnace into the main ducting. The thermo on the wood furnace turns on and off the blower only (No Propane used) on the main furnace. If the fire dies or we aren't home for a long time, the thermostat upstairs calls for heat, the propane furnace comes on. I'll have better pictures soon which may help.

 

[laynes69]

Looks nice, the only thing you will have to come up with is a by-pass if you decide to run the gas furnace in the fall, or spring. The cold woodfurnace takes alot of heat to finally push heat from the furnace through the house. Also if you run a/c through the woodfurnace, it will eat it up from the inside out. I don't have a/c yet so I'm not going to worry about it. It does make a hell of a difference with an install like that, than the conventional (Parellel) install.

 

[matt701]

I'm going to keep my eye on it, but I don't think much/any moisture will cause problems with the firebox in the summer from using the A/C.

 

[matt701]

I've had some time to test the new setup and am finding that I'm burning a lot less wood and its a lot easier to regulate the temperatures in the house. I definately gained efficiency by hooking it up to heat the return air. I'm using an adjustable thermodisc and have it set to 110 on and 90 off which makes my main furnace fan run more, but it circulates a lot more air and heats better. Also, there's not an issue with running only the propane furnace, I feel heat rather quickly upstairs and it hasn't had to kick into high stage yet to heat the house, even when it was really cold out. I also asked my buddy who helped me install it (Senior Engineer at Carrier, does HVAC on the side) about any possible problems with moisture affecting the wood furnace from the AC coil in the summer, and he said it wouldn't be an issue. I wish I remember what he said, but something about dew point and the onboard computer controlling the airflow to prevent it. Anyhow, here's some completed pics. It's a little scary taking tin shears to your furnace and rip the top and side apart, but what a difference it made.