Outside Wood Forced Air Furnace:
- Thread starter hapec12
- Start date
Help Support Arborist Forum:
To be clear are we talking:
1) an add on unit
2) an Outside forced air furnace with or whitout add on
3) an OWB
I have no expericene with any of these, only a wood stove that my step mom uses to heat her house, but I am looking into this for my self although I am not goign to be able to install a OWB due to living in the ****** (city) I will be following this pretty close thanks for all that respond to the thread
1) an add on unit
2) an Outside forced air furnace with or whitout add on
3) an OWB
I have no expericene with any of these, only a wood stove that my step mom uses to heat her house, but I am looking into this for my self although I am not goign to be able to install a OWB due to living in the ****** (city) I will be following this pretty close thanks for all that respond to the thread
Outside wood forced air furnace, no add-on. A stand alone, such as a Hopsco brand.
So tell me the reasons.
I have one that I built about 4 winters ago, the thread link is in my sig but the thread seems to be missing. I absolutely love it except if it's warmer than 30 out then it's just too damn hot! LOL
My only concern is that I should have some sort of fire damper in case of an emergency but other than that it's nice to have the floors warm and have it 71 in my kitchen every morning. I live in a ranch with a walk out basement and it's piped in down there.
davve
My only concern is that I should have some sort of fire damper in case of an emergency but other than that it's nice to have the floors warm and have it 71 in my kitchen every morning. I live in a ranch with a walk out basement and it's piped in down there.
davve
brenndatomu
Hey you woodchucks, quit chucking my wood!
Kinda tough when most of the AS archived material seems to be missing...that is if the search function even works in the first place!
Last edited:
had a lil house forced air outside for 3 years. thought it was great...... until we got the heatmor..... now i know...... it sucked really. no heat regulation hotter than the devil himself in the house pretty much all the time. save your money.... get an OWB. wish i would have listened when i was told that......
A two line answer didn't reveal much either.
I would be interested in reading about some of the reasons you believe they are not popular. They seem to be in my neighborhood, as I have at least 4 neighbors that use them, all installed in the last 5 years.
forced air isnt a bad bad thing..... it makes heat... which is what ur after. but, the control of that heat is not as consistant as with the OWB. They r popular to some i guess, but if they ever used a OWB they would not go back to forced air. Like i said prior, i had one.... and would not go back since the OWB. The forced air also has the chance of a hole occurring in the firebox causing the smoke and a chance of a spark to enter ur home..... and we all know what can happen when a spark gets in a house,,,,,,,,,, a new house..... 
lapeer20m
ArboristSite Operative
air is a poor medium for transporting heat. Water is one of the best materials on earth for transporting heat.
Another advantage of water heat is that you can easily control the temperature in several rooms at one time.
Forced air heat is much more difficult to transport to various rooms, unless you are going to use extensive duct work. Forced air also tends to be more dusty and dry. Forced air is a realatively poor method of heating a room. Radiation, like you get from cast iron baseboard heat is much more desirable.
Another advantage of water heat is that you can easily control the temperature in several rooms at one time.
Forced air heat is much more difficult to transport to various rooms, unless you are going to use extensive duct work. Forced air also tends to be more dusty and dry. Forced air is a realatively poor method of heating a room. Radiation, like you get from cast iron baseboard heat is much more desirable.
Forced air is a fine way to heat and can be regulated and it can use far less wood than a owb if its a modern efficient unit . It is easier to heat air than water but water can hold heat better it also takes forever to heat up a cold house ..putting an air furnace in a shed outdoors and trying to channel the air into the home is an inefficient way to move heat. . There's a lot of heat loss in this configuration . One thing you must realize in your quest is that wood heating technology has come along way in last couple decades and most guys use a cheap big box store furnace that is not much more than a campfire in a box with a blower and some sheet metal .by putting the furnace outdoors your losing alot of radiant heat that the furnace itself gives off and also putting outside cools it and the ducting off before it enters the home then there's the burden of having to go out in frigid snowy weather and feeding it and such , its s redneck way of trying to heat a house .an owb would be better outdoors but you got a big investment and you better live to cut firewood . Owb give longer burn times but that's because they have giant fire boxes and hold a lot of wood . Most economy owb are forced draft low tech smoke dragons
Last edited:
Mine has a hot air duct and a cold air return, both 10" diameter and aprox. 6' long. It is NOT tied into my existing duct work for my hot air oil fired heating system. I live in a walk out basement ranch and just the heat coming in is enough to heat my home. I will admit that room is upwards of 85 deg. but we don't use it much in the winter.
The air traveling through the duct from the outside unit to the house travels so fast that there really isn't much time for any heat loss. I have my ducts insulated but don't think I really needed to from the info I can find online. I think my unit is just too big for my size house. I now want to build an OWB to do exactly what these guys are telling you, to be able to moderate and control the heat.
I don't want the mess or the danger of a woodstove in my home.
dave
The air traveling through the duct from the outside unit to the house travels so fast that there really isn't much time for any heat loss. I have my ducts insulated but don't think I really needed to from the info I can find online. I think my unit is just too big for my size house. I now want to build an OWB to do exactly what these guys are telling you, to be able to moderate and control the heat.
I don't want the mess or the danger of a woodstove in my home.
dave
Thank You gentlemen for your responses, except Del the Wise Guy, with your Dissertation words. I have searched for information, and thought this is where I could come to further gather insight and knowledge. Maybe I am Mistaken, but then again theirs One In Every Crowd, Right.
Well Del, with the fact that I can keep my house warm for 12 hrs or more on 4-5 chunks of well seasoned wood I would have to disagree with you on the heat extraction comment. On my unit being too close you are right and that is one reason I am doing away with it.
dave
dave
My (indoor) furnace is forced air...
The thing is, a forced air, wood-fired furnace works a bit differently than a gas or oil fired furnace. The wall thermostat starts/stops the draft blower, but the circulation blower starts/stops whenever the air jacket around the firebox reaches a set temperature... if it didn't the furnace could easily overheat. While the fire is in "idle" mode the furnace is a lot like a wood stove, putting out low(er) heat continuously. When/if the house temp drops below the thermostat set point and the draft blower starts the furnace produces very high heat to catch-up. So, unlike an OWB, ya' can't just load it plumb full and forget it for 15-25 hours 'cause it'll heat ya' clean out'a the house (even if the draft blower never runs)... more like a stove, ya' need to match the loading to the conditions of the day. To some extent ya' still need to control the temperature of the house by how much, and what type of wood ya' toss in the box. On a warmish day you might just keep a small fire going... adding two or three small splits every 3-4 hours or so, just enough to keep the circulation blower cycling on a few times an hour.
Now, that ain't no big deal if'n the furnace is indoors... but what a huge pain-in-the-azz if'n it's outdoors. I do add a bit extra before bed, but once the sun goes down it takes a bit more... and I also have the thermostat programed for a few degrees lower so draft blower won't start as much and eat-up the relatively small amount of fuel halfway through the night. Once it gets colder it won't be as much of a "balancing act" and I'll be able to load it heavier before bed. Personally, I don't like the idea of going outside to load the box during winter so I wouldn't have an OWB either... but if I had to have an outside wood-fired furnace I'd go with an OWB over forced air hands down. If I had to go outside to load the box, I'd only wanna' do it once a day at the most, once every two days would be even better. With an outdoor, forced air, wood-fired furnace I'd be going out there several times a day this time of year, adding just a little at a time so we don't cook... and likely be going out there 3 or more times a day during mid-winter so we don't freeze (and one of those times would be immediately after climbing out'a bed in the morning... and that would suck sour owl crap!).
Oh... I should add that my forced air is tied into the gas furnace duct work, so it's distributed throughout the whole house... which is a whole lot different than just having it blow into one basement room. If I load the box even ½ full when outside temps are above 30° my house will become a 90° oven in less than an hour (even with the thermostat turned off!).
The thing is, a forced air, wood-fired furnace works a bit differently than a gas or oil fired furnace. The wall thermostat starts/stops the draft blower, but the circulation blower starts/stops whenever the air jacket around the firebox reaches a set temperature... if it didn't the furnace could easily overheat. While the fire is in "idle" mode the furnace is a lot like a wood stove, putting out low(er) heat continuously. When/if the house temp drops below the thermostat set point and the draft blower starts the furnace produces very high heat to catch-up. So, unlike an OWB, ya' can't just load it plumb full and forget it for 15-25 hours 'cause it'll heat ya' clean out'a the house (even if the draft blower never runs)... more like a stove, ya' need to match the loading to the conditions of the day. To some extent ya' still need to control the temperature of the house by how much, and what type of wood ya' toss in the box. On a warmish day you might just keep a small fire going... adding two or three small splits every 3-4 hours or so, just enough to keep the circulation blower cycling on a few times an hour.
Now, that ain't no big deal if'n the furnace is indoors... but what a huge pain-in-the-azz if'n it's outdoors. I do add a bit extra before bed, but once the sun goes down it takes a bit more... and I also have the thermostat programed for a few degrees lower so draft blower won't start as much and eat-up the relatively small amount of fuel halfway through the night. Once it gets colder it won't be as much of a "balancing act" and I'll be able to load it heavier before bed. Personally, I don't like the idea of going outside to load the box during winter so I wouldn't have an OWB either... but if I had to have an outside wood-fired furnace I'd go with an OWB over forced air hands down. If I had to go outside to load the box, I'd only wanna' do it once a day at the most, once every two days would be even better. With an outdoor, forced air, wood-fired furnace I'd be going out there several times a day this time of year, adding just a little at a time so we don't cook... and likely be going out there 3 or more times a day during mid-winter so we don't freeze (and one of those times would be immediately after climbing out'a bed in the morning... and that would suck sour owl crap!).
Oh... I should add that my forced air is tied into the gas furnace duct work, so it's distributed throughout the whole house... which is a whole lot different than just having it blow into one basement room. If I load the box even ½ full when outside temps are above 30° my house will become a 90° oven in less than an hour (even with the thermostat turned off!).
Last edited:
DCC
ArboristSite Lurker
I have a forced air wood furnace also. Whitespider nailed it!
iowa
Addicted to ArboristSite
Why do you need it outside? Because 4-5 others on your street have them outside? I think forced air heat from outside isn't the best idea as you lose heat coming in.
I went with a kuuma vaporfire 100 last yr. It's in my walk out basement and the heat stays IN my house. It's also very safe to use and efficient. It is tied right into my ductwork and my entire house stays warm. Not just one room piping hot and then the room furthest from unit ice cold.
I went with a kuuma vaporfire 100 last yr. It's in my walk out basement and the heat stays IN my house. It's also very safe to use and efficient. It is tied right into my ductwork and my entire house stays warm. Not just one room piping hot and then the room furthest from unit ice cold.
Similar threads
