Remember your not trying to put 2600 cfm up into your house. You only need to worry about the 1600 cfm for the house. The 1000cfm you just want to circulate through the system and grab the heat from it. I know its a little confusing. Don't get me wrong you will get more that 1600cfm up through the duct, but not 2600.
I have the same furnace a US Stove 1500 hotblast. We had the same problem. Dad had installed it 18 years ago in the basement in a parallel installation. There was alot of dust in the home, and not to mention the danger of combustion gasses being pulled from the LP furnace, or wood furnace at that matter. I decided to do away with the blowers on the rear of the furnace and use my LP furnace blower to distribute the ductwork through the home. I just rebuilt the furnace this summer and its about 20 years old. I cut an extra 8" hole between the other 2 off the top of the furnace for the heat to go into the main trunk. Then I cut 2 8" holes in the back of the furnace where the blower were, and 1 8"duct on the side. I had to keep the airflow about the same as the furnace. So when the wood furnace hits its ON temp, the Lp furnace blower only will kick on. The woodfurnace acts as a large heat exchanger, and also takes advantage of the cold air system. This is the most efficient setup for us (Series). When I put new ductwork in the home, I made sure NO air was drawn from the basement where the wood furnace was. 2 things here, no dust and less chance of co2. I will tell you that these furnaces are not made for anthracite coal. Soft coal should work okay. Its 1 degree here right now, wind chills of -19 and our whole house is 74 degrees with our setup. We have yet to have the gas furnace come on. Above the furnace is the return air, and above the woodfurnace is the heat trunk. We heat 2400 square feet quite easily.
Laynes69...From what I'm seeing the cold air return is going into the back of the LP furnace and a distribution box is on the top of that same LP furnace. From that distribution box the (3) 8" ducts tie into the side and back of the wood burning furnace blowing the cool air around the wood furnaces outer firebox. The warm radiant air is then distributed through the (3) 8" ducts on the top of the wood furnace and blow into the warm air supply ducts through the house. Am I correct? It sounds like your hookup works fine for your house if it keeps 2400 sq. ft. at 74 with a -19 outside. Do you burn coal in your stove or just wood? My stove is burning bituminous coal fine now. I had a few wrinkles to work out burning coal, but think that I got them all taken care of.
I haven't had time to work on my cold air return ducts yet, but need to get a move on!!! This weekend I had to pull an engine out of my brother in-laws pickup truck which led me to no time to work on my own projects.
The air filter in the cold air return on the back of the furnace now is black and needs changed after about 5 days of burning. The trouble that I'm running into now is the black stove pipe is in the way. I can't take the cold air return straight up towards the ceiling or it will hit this black stove pipe. I have find a way to run the duct up to avoid the stove pipe. Anybody have suggestions? If you take a look at my pics. your will see what I'm talking about. I would like to keep it square, but if I need to I will separate it with two 8" ducts.
Thats correct. I am burning wood because anthracite wasn't working out too good for me. I have kept the house at 72 today, and currently its 2 degrees out. This setup works well. I would just tie into the cold air box, then go off to a side and run it into your living space. This would help circulate the hot air. We have to change our furnace filter every 2 weeks, because our blower will operate 23 out of 24 hours in the day. It has a ton of airflow throught the system. This is how the home stays warm. I have it set for 140 on and 85 off. As long as a I have a good healty fire the blower will keep running. Also we burn less wood with this setup due to more heat throughout the home. To give you an idea of what we heat, here is our home. We have 10 foot ceilings, and the house is 150+ years old.
Laynes69.. Have you ever tried burning bituminous coal? What did the anthracite do when you tried burning it? I ditto Chris's comment... Very nice house!! I'd hate to see the bill when you replace all of them windows though. How well is your house insulated? I have a very poor insulated house and in the process of rectofying that problem on the second floor!!! It is very drafty in the basement which the cold is coming up through the hardwood floors to the second story.
I couldn't get enough heat from the anthracite coal. It wasn't burning at its prime. Where the base of the firebox would starve the rest of the pile for air. Our house is insulated with urea-formaladyhyde foam with a high r value. Also all the windows are double hung double pane vinyl windows. The outer windows are triple track storm windows. I have burned lump coal but not alot of it at one time. I need to try soft coal but I can't buy enough to just give it a try. Insulation will make a world of difference in any home. Its cheaper to heat this home than my grandmas trailer.