# thinking of buying a 1557M



## brickman (Dec 31, 2008)

Hi, I am thinking about buying a 1557M furnace. i am wanting to add it on to my central furnace. My question is if the blowers (two 550cfm blowers) will be enough to push the air to my existing furnace. They will be about 25' apart. I would like to install the 1557 in my garage and run the heat pipe to the crawl space. Thats where my central furnace is located. To do this I would have to run the heat pipe with a double 90 elbow to get it going down to the floor. Would this inhibit the air flow to much? I have a 2200 sq. ft. two story home. Just want to know if this unit will do the job. Thanks, any input would be appreciated.


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## Stihl_WoodBandit (Dec 31, 2008)

I just bought one from the TSC in Eaton cause i got it on scratch & dent sale.  The one in Troy has 3 units still for $1150.  The two 550 cfm blowers will definitly move some air.  There is a way you can wire it in to your existing forced air furnace also.  The both of them will keep your house warm.  

I'm really happy with mine.  Had it since 12/26/08 and havent burned a drip of propane! You'll be happy with one if you decide to purchace it.


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## laynes69 (Dec 31, 2008)

The furnaces work well when set up properly. Also not too expensive. You will have issues with the furnace installing it like that though. You won't get the flow on a 25' run with 2 90's on those blowers. And with 2200 square feet, that setup won't work. Also I wouldn't recommend installing the unit in a garage. I wouldn't want the boom factor if anything around it is combustible. Is there any way for you to install it  by the furnace? Is the current furnace in the crawlspace? And why would you want it in the garage? the unit would work, only if installed properly.


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## brickman (Jan 1, 2009)

I was at the TSC in troy on 12/31/08 and they still have three units, but marked down to $976.00 I don't have any other place to put the wood furnace in my house. Don't have a basement just a crawl space. And yes my central furnace is in the crawl space under the house. I don't store any combustibles in the garage. The only way to get heat pipes from the 1557 would be to turn the pipes down to the floor and then into the crawl space to my central furnace.


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## laynes69 (Jan 1, 2009)

You could try it. I would contact the insurance agency and see if it would be okay. I could see alot of heat loss, and flow loss through the 2 ducts. Thats a good price for the unit, but to me a bad way to install a furnace. How about a freestanding stove in the home?


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## Stihl_WoodBandit (Jan 1, 2009)

Dang it I had to drive down to Dayton to get a slightly dented one for $976.  It figures that now they have them in troy for the same price.  

With your possible setup, the 90's and the length of duct are a negative, but I would have thought that if you hooked it up to your furnace that the furnace fan would help pull the air from the garage furnace.  It is possible to get a larger cfm fan for the wood furnace.  

Maybe get a HVAC contractor out to your house and get their opinion on it.  

Somebody else on here ought to be able to offer some better advice for you.


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## brickman (Jan 1, 2009)

I have thought of a free standing wood burner in the house, but like the more even heat distribution of the add on furnace. I will do some more research and maybe have a HVAC person come out. I think all i have to accomplish is to get the heat to my central furnace plenum, (about 25') and let the central furnace blower push the air through the house. They do make a bigger unit with a muti speed fan for about $500 more.


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## laynes69 (Jan 1, 2009)

That would be the unit that would be better. Still ????????? about the garage, but with that unit it would probably work. If you locate a woodstove correctly, it can do alot of good in a home. Hows you home laid out?


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## jdew1920 (Jan 1, 2009)

Definately talk to an HVAC guy.  I'm sure it's doable.  You could always start with the cheaper unit with 2 smaller blowers and see if it works, if needed you can upgrade to a larger fan for less than the $500 upgrade.  I would try to use larger duct like 8x16 or 8x20 with large radius turns to minimize pressure loss and only expect the wood furnace to get the heat to the main furnace plenum and allow that blower to circulate it through the house.


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## smokinj (Jan 2, 2009)

brickman said:
			
		

> Hi, I am thinking about buying a 1557M furnace. i am wanting to add it on to my central furnace. My question is if the blowers (two 550cfm blowers) will be enough to push the air to my existing furnace. They will be about 25' apart. I would like to install the 1557 in my garage and run the heat pipe to the crawl space. Thats where my central furnace is located. To do this I would have to run the heat pipe with a double 90 elbow to get it going down to the floor. Would this inhibit the air flow to much? I have a 2200 sq. ft. two story home. Just want to know if this unit will do the job. Thanks, any input would be appreciated.


should work well


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## brickman (Jan 2, 2009)

My house is a cape cod design, story and a half. A lot of small rooms down stairs and two bedrooms upstairs. The house is 11 years old , with 2 x 6 exterior walls. So there is extra insulation in the exterior walls. I did find an installation on the web where someone hooked up a hotblast 1500 furnace to there existing down draft furnace. I would have to run my heat pipe somewhat the same way to get it to my crawl space. I have added a some pics of this, tell me what you think. Looks like he ran both 8" heat pipes in to one 8" then to furnace


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## smokinj (Jan 2, 2009)

cant really tell from that pic. but I would run both 8's to the furance


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## laynes69 (Jan 2, 2009)

2 8" ducts reduced into 1 8" duct= 1 8" duct of heat. A 8" ducts carries 200cfms of air. The larger unit already has a larger blower. Also has a large opening on the top for a plenum. You can run an 8x18, or 8x20 and get your heat into the home. With 2 8" lines, and 2 90's in each you will cut your flow in half. By the time you make it to the plenum, you have not enough flow for the system, no pressure to get the heat into the plenum  of the furnace. You will need a backdraft damper in the main furnaces plenum, which will stop backflow. Your best bet would be get a 1600 and go from there. Also when a line in ran into the home, insulate that line. One other thing is in order to get the system to work properly, you will need to get a cold air return into the house from the furnace. And last, with the furnace being in the garage, the 1600 is insulated, so you won't lose alot of heat due to an unheated space.


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## brickman (Jan 2, 2009)

Very good points. That is what I thought might be my problem, not enough air flow into the plenum when my central furnace fan came on.Seems like you have to match or be higher with the air flow from the add on furnace, to just make it into the existing plenum. I like the idea of a plenum control switch in the central furnace. That way the air from the add on could get in before the central fan comes on, but seems like the fan would just cycle on and off a lot with the temperatures. I would like to use the 1557 but if it isnt big enough than I would rather spend the extra and get the 1600. I can get a 1557 for $976 and a 1600 for $1349, not alot of difference.


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## smokinj (Jan 2, 2009)

brickman said:
			
		

> Very good points. That is what I thought might be my problem, not enough air flow into the plenum when my central furnace fan came on.Seems like you have to match or be higher with the air flow from the add on furnace, to just make it into the existing plenum. I like the idea of a plenum control switch in the central furnace. That way the air from the add on could get in before the central fan comes on, but seems like the fan would just cycle on and off a lot with the temperatures. I would like to use the 1557 but if it isnt big enough than I would rather spend the extra and get the 1600. I can get a 1557 for $976 and a 1600 for $1349, not alot of difference.


I would look at 1950 model uses alot less wood and more btu's
http://www.usstove.com/proddetail.php?prod=1950


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## laynes69 (Jan 3, 2009)

the 1950 is a nice unit. But.....If it is bought w/o a blower then it must be installed in series with the current furnace. Which isn't possible with that setup that he has. Plus price, the least I saw the 1950 for was 2000. If I could have gotten the financing with the interest I wanted, I would have had it. Ideally you don't want to use the central furnaces blower if possible. When the heat from the woodfurnace enters the plenum of the main furnace, its hot. Now kick on that central furnace blower and it will temper the air, to where you will luke warm air at best. Now get the cfms in the larger ducting, get a return on the system and install a damper in the plenum of the main furnace. With enough flow from a large blower on the wood unit, you get enough pressure to force that heat through the ducting w/o the central furnaces fan. Therefore only wood warm heat.  With the 1600 you can choose 1100,1250, or 1400 cfms of air through the blowers. You wouldn't have to modify the furnace in any way. You could possibly heat with the other, but it would need to be modified quite a bit. Like I said before though, Return air with the woodfurnace is key. You want that clean 70 something degree air from the house to circulate the firebox, not the cool air of the garage. Plus its not a bad thing to go one step larger, especially on those below zero nights. You'll appreciate it.


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## smokinj (Jan 3, 2009)

laynes69 said:
			
		

> the 1950 is a nice unit. But.....If it is bought w/o a blower then it must be installed in series with the current furnace. Which isn't possible with that setup that he has. Plus price, the least I saw the 1950 for was 2000. If I could have gotten the financing with the interest I wanted, I would have had it. Ideally you don't want to use the central furnaces blower if possible. When the heat from the woodfurnace enters the plenum of the main furnace, its hot. Now kick on that central furnace blower and it will temper the air, to where you will luke warm air at best. Now get the cfms in the larger ducting, get a return on the system and install a damper in the plenum of the main furnace. With enough flow from a large blower on the wood unit, you get enough pressure to force that heat through the ducting w/o the central furnaces fan. Therefore only wood warm heat.  With the 1600 you can choose 1100,1250, or 1400 cfms of air through the blowers. You wouldn't have to modify the furnace in any way. You could possibly heat with the other, but it would need to be modified quite a bit. Like I said before though, Return air with the woodfurnace is key. You want that clean 70 something degree air from the house to circulate the firebox, not the cool air of the garage. Plus its not a bad thing to go one step larger, especially on those below zero nights. You'll appreciate it.


I seen that 1950 at tsc for 1400.00 (its one fine furance) and the way my back fells today i think its in my future 40 percent less wood I'll take it!lol


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## laynes69 (Jan 3, 2009)

To give you an idea of flow, a 8x24 will give you 1100 cfms. An 8x30 will push 1400 cfms. Compare those to 2 8" trunks, which will push 400 total. You'll need that large trunk to move the heat 25 feet into the home. Especially with 2 90's. Also you need to look at if you have enough area on the central furnaces plenum to tie into. If you have a newer home, do you have a coil in the furnace? You would need to go above that coil with a damper. The heat of the woodfurnace can harm the coils of the c/a units or heat pumps. If you can get 8 to 10 inches above the coil, if you have one you may be okay. Post some pictures and it will give a better idea on what to do.


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## laynes69 (Jan 3, 2009)

RKO was the only place around here that carried them. I doubt there are any now. If they were 1400 in indiana, I would drive there to pick one up. RKO doesn't offer 12 mo no interest no payments, So I wasn't about to get 22%interest with perfect credit. Thats a steal, they list at 3000+ on the website.


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## smokinj (Jan 3, 2009)

laynes69 said:
			
		

> To give you an idea of flow, a 8x24 will give you 1100 cfms. An 8x30 will push 1400 cfms. Compare those to 2 8" trunks, which will push 400 total. You'll need that large trunk to move the heat 25 feet into the home. Especially with 2 90's. Also you need to look at if you have enough area on the central furnaces plenum to tie into. If you have a newer home, do you have a coil in the furnace? You would need to go above that coil with a damper. The heat of the woodfurnace can harm the coils of the c/a units or heat pumps. If you can get 8 to 10 inches above the coil, if you have one you may be okay. Post some pictures and it will give a better idea on what to do.


you can push alot more the 200 cfm through 8 in. pipe


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## laynes69 (Jan 3, 2009)

Here is a flow chart to give you some ideas on ducting. 

http://www.hamiltonhomeproducts.com/images/ductwork/DuctChart.gif


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## smokinj (Jan 3, 2009)

thats all well and good to know but you can get alot more than that!


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## smokinj (Jan 3, 2009)

laynes69 said:
			
		

> RKO was the only place around here that carried them. I doubt there are any now. If they were 1400 in indiana, I would drive there to pick one up. RKO doesn't offer 12 mo no interest no payments, So I wasn't about to get 22%interest with perfect credit. Thats a steal, they list at 3000+ on the website.


Iam going there saturday i will look at them very nice furance showed the wife and it was 1399.00 i hope they havent went up?


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## jdew1920 (Jan 3, 2009)

brickman said:
			
		

> Very good points. That is what I thought might be my problem, not enough air flow into the plenum when my central furnace fan came on.Seems like you have to match or be higher with the air flow from the add on furnace, to just make it into the existing plenum. I like the idea of a plenum control switch in the central furnace. That way the air from the add on could get in before the central fan comes on, but seems like the fan would just cycle on and off a lot with the temperatures. I would like to use the 1557 but if it isnt big enough than I would rather spend the extra and get the 1600. I can get a 1557 for $976 and a 1600 for $1349, not alot of difference.



There are ways to install the duct work so that your main furnace blower is not working against the wood furnace. The duct work coming from the wood furnace should enter the plenum in such a way that the blower in your main furnace does not push directly against the wood furnace flow.  For example you can enter the plenum at an angle in the direction of the air flow, or install a baffle in the main furnace plenum that directs the wood furnace flow in the direction of the main furnace flow.


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## brickman (Jan 3, 2009)

I would rather get  the bigger unit instead of modifying the smaller one. I plan to get the return air from the return air duct at the central furnace. Was just going to tap into it. My central furnace is located in the center of the main trunk line. The line is about 50' in length. So that means I would have to run about 25' of heat duct from the wood furnace to my central furnace plenum, then the 50' of main trunk line. You think the 1600 would do this alone, without help from the central furnace blower. What about going into the main trunk line at one end. If I do not need the help of the central furnace fan, this would save me about 10 or 12' of heat pipe from the wood burner to the main duct


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## laynes69 (Jan 3, 2009)

If you have the ductwork sized properly in the home. Stepped down to keep the pressure in the ducts, then you should be okay. The trick is, if feeding it into the plenum of the central furnace, you need a damper or a diffuser so it doesn't backfeed into the central furnace. This keeps your pressure up in the lines so the heat can push through the trunk, through the ducts. You will keep pressure till it starts to hit those open ducts. You will of course lose some heat at the end, but with a 1400 cfm blower, and your trunk from your wood furnace. I think it would work.


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## smokinj (Jan 3, 2009)

brickman said:
			
		

> I would rather get  the bigger unit instead of modifying the smaller one. I plan to get the return air from the return air duct at the central furnace. Was just going to tap into it. My central furnace is located in the center of the main trunk line. The line is about 50' in length. So that means I would have to run about 25' of heat duct from the wood furnace to my central furnace plenum, then the 50' of main trunk line. You think the 1600 would do this alone, without help from the central furnace blower. What about going into the main trunk line at one end. If I do not need the help of the central furnace fan, this would save me about 10 or 12' of heat pipe from the wood burner to the main duct


imo still not enough cfm the 1600 is a step in the right direction but your still trying to push that air 25 ft before it hits the main furance use blowers inconjuction of your other furance would work good! the main duct coming off the 1600 is 18x13


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