Are In-Line Duct Fans practical?

[pring7]

Moving heat has been on my mind for a while and I have brought it up in this other thread https://www.hearth.com/talk/threads/70539/ , but this is a little different so I started a new one.

After much consideration about through the wall fans, I am leaning on ordering this type of system instead.

(broken link removed to http://www.solerpalau-usa.com/res_mff.html)

(broken link removed to http://www.solerpalau-usa.com/pdfs/IOMS/TD) Installation Instructions.pdf

http://www.solerpalau-usa.com/brochures/Residential_Light_Comm/TD_Extended_Brochure.pdf

I spoke with the Soler Palau rep today and I think that this might be an easy install and prime application for my house. Instead of heating my sunroom and the adjacent room through the host wall, I will be able to hopefully shoot warm air to the far reaches of my house. After speaking with him I am leaning of the TD 200 –TD 250 which blow 200 or 250 cfm respectively. I think the 250 is better for volume and I would also utilize a 10†duct with it.
The air will most likely draw horizontally from the highest point in the room and then flow to three exhaust points in each bedroom of my home. The longest run will probably be less than 50’, but I will need to measure and confirm. There is a large attic space that I can run this through and it will be above 18†of blow in insulation (hopefully a good noise dampener).

Pros:
1. The motor will be in the attic, cutting down on noise.

2. Hopefully a productive distribution of heat throughout the house

Cons:
1. Higher initial cost

2. Higher operational cost

3. A lot more work to install

4. The unknown factor of whether this system will perform as hoped for (Maybe you have experience)


I would like to see if anybody here has used similar systems to distribute heat. If so, how has it worked out? Did you set it up with a simple switch, or did you use a 5 amp thermostat?

Thanks

 

[realstihl]

I've done it before in my home before this one. The biggest drawback is the heat loss in the long duct run. On mine I ended up blowing loose fill over the duct. You could also lay a fiberglass blanket over it. Even the insulated duct is not enough if it's in an unconditioned space. It will help and sounds like our set up was about the same.

 

[pring7]

Well, I figured that would be a problem if it was on a thermostat, but would it still be a problem if it was pretty much running continuously? I figured it would run whenever we were using the wood stove and that the loss would be little. A run of 50’ doesn’t seem long to me. Did you use insulated ducts? I could easily throw some lose fill or a blanket on top as you said too.

 

[realstihl]

Yes, I initially used insulated duct. R-4.5 I think. Mine was set up using a low voltage thermostat but a line voltage cooling thermostat will work fine. Also you might want to try it backwards and move the cool air back to the stove room. Either way it will work but don't think it will keep those far rooms at the same temp as the stove room. Won't happen.

 

[pring7]

The way the room is configured I will have French doors going out to the sunroom where the stove will be set. I figured that if I would be able to draw air back to the sunroom by simply opening the doors. Maybe setting a standard fan to blow the cold air out would be the best bet since that could be put at a lower level. It should be fun figuring out what approach works best. Maybe just cracking the door will be sufficient for drawing the cool air towards the stove.

 

[woodgeek]

I have used the smaller version of the soler-palau to vent my bathrooms--and am very pleased with their quietude and performance--no trouble after several years.

As I pointed out in the thread you linked, heat xfer in BTU/h is roughly CFM*Delta_T(°F). IF the ceiling of your stove room is 30°F warmer than your bedrooms, then 250 CFM will deliver 250*30 = 7500 BTU/h ~ 2.1 kW (thermal). Should heat that end of the house 50% more than a 12A elec space heater on high (5000 BTU/h).

Uninsulated duct would be about r=0.5. a 50' run, with a 3' perimeter is 150 sq ft. At R-0.5, it would lose 300 BTU/h*degF. If the air inside were 100°F, and it was 30 deg in your attic, you would lose 300*70=21000 BTU/h, or more than you put in. IF you assume R-4 (minimal insulation), then you get 150/4 = 38 BTU/hdegF, or a loss of 2660 BTU/h, or about 10 deg F cooling and a loss of 1/3 of your heat. Conclusion: use R-8 or better insulation, and you will lose <20%.

 

[Don2222]

Hello

I got my In-Line Duct fan for 6" Ductwork right at Home Depot. Works great!

The Fan is connected to the control panel speed control, manual and automatic wall switches upstairs. See control pic

She Honeywell Line Voltage Heating and Cooling Thermostat is set to 74 Degrees.

So when the air above the stove climbs over 74 Degrees the fan comes on and as you can see pushes out 150 Degrees of heat in the Living room and kitchen upstairs!! Better than any gas, electric or Oil furnace I know of ! Best of all, it is CHEAP heat !! LOL

I should however assure members that Hearth.com is not recommending this procedure and there are cautions and engineering to consider if undergoing this type of modification.

 

[pring7]

Well, it seems like this may be a decent way to go then. I have a small space heater in my son’s bedroom now that is only 450 watts http://www.eheat.com/. This little heater makes a significant difference in the temperature of the room, so I think that ducting them instead would be a great way to optimize the heat from the new wood stove.

I think in terms of fire hydrants and water grid systems sometimes since I am a firefighter. A dead end line isn’t as good as a loop, but would the same apply to a duct system? There’s a-lot of space up there so I could get creative with trying to distribute heat to various points, but I think that simpler in this case would probably be more effective. It will most likely be as straight a run as possible with three exhaust points, but would it be better to loop it back to itself? The rep that I talked to today said that for every 45 degree (maybe he said 90) bend you might as well add 5 foot of distance to the projection.

You’ve sold me on the insulated ducts also. I’m glad I took my time and looked into the various options. I appreciate the pictures too. Thanks for the advice.

 

[begreen]

Hello

I got my In-Line Duct fan for 6" Ductwork right at Home Depot. Works great!

The Fan is connected to the control panel speed control, manual and automatic wall switches upstairs. See control pic

She Honeywell Line Voltage Heating and Cooling Thermostat is set to 74 Degrees.

So when the air above the stove climbs over 74 Degrees the fan comes on and as you can see pushes out 150 Degrees of heat in the Livingroom upstairs!! Better than any gas, electric or Oil furnace I know of ! Best of all, it is CHEAP heat !! LOL

And against code I should add.

 

[Don2222]

Hello

I got my In-Line Duct fan for 6" Ductwork right at Home Depot. Works great!

The Fan is connected to the control panel speed control, manual and automatic wall switches upstairs. See control pic

She Honeywell Line Voltage Heating and Cooling Thermostat is set to 74 Degrees.

So when the air above the stove climbs over 74 Degrees the fan comes on and as you can see pushes out 150 Degrees of heat in the Livingroom upstairs!! Better than any gas, electric or Oil furnace I know of ! Best of all, it is CHEAP heat !! LOL

And against code I should add.

BeGreen

Before you jump on us, show me the code for NH that this violates please?

The most commonly used codes are NFPA 101, The Life Safety Code® and NFPA 1, The Fire Prevention Code

More specific
All persons constructing, installing, maintaining or repairing chimneys, fireplaces, solid fuel burning appliances or vents in any structure shall comply with the requirements of NFPA 211 as adopted under part Saf-C 6013

On-Line edition
(broken link removed to http://www.nfpa.org/assets/files/PDF/ROP/211-F2002-rop.pdf)

I went thru it and most of it relates to stove clearances and flue requirements, not heated convection air movement.
I also do not see any temperature requirement for convection air and maybe there should be a high limit but there is not!!
So if I have missed something please tell us now or never again. Thanks

You also said that to J-Takeman for doing the same. Remember?

https://www.hearth.com/talk/threads/67884/

Here is his answer and I quote:
"I actually talked to my local fire marshall before I even started this. I showed him liturature from a bixby UBB and my old manual from the bigE. Both of those stoves had listed an option for connecting duct work. But they later removed it from the manuals. Due to hot vent issues. Floor vents got to hot and peeps burned there toes on them. Thats what I was told by Bixby anyway. This was addressed with more air flow to cool the heated air. Exactly the same as the pellet furnaces do, High CFM blowers with cooler convection air.

He saw one issue an I addressed it with the snorkle. Sealing the connection between the stove so smoke would not enter the convection path.

He agreed and ok’d my mod. We also researched several of the pellet furnaces and the only thing this lacks is an air return system. "

 

[smwilliamson]

BeGreen

Before you jump on us, show me the code for NH that this violates please?

take a look in NFPA 90E, I'll take a look too.

 

[begreen]

IRC 2003

R602.8 Fireblocking required. Fireblocking shall be provided
to cut off all concealed draft openings (both vertical and horizontal)
and to form an effective fire barrier between stories, and
between a top story and the roof space. Fireblocking shall be
provided inwood-frame construction in the following locations.
1. In concealed spaces of stud walls and partitions, including
furred spaces and parallel rows of studs or staggered
studs; as follows:
1.. Vertically at the ceiling and floor levels.
2. At all interconnections between concealed vertical and
horizontal spaces such as occur at soffits, drop ceilings
and cove ceilings.
3. In concealed spaces between stair stringers at the top and
bottom of the run. Enclosed spaces under stairs shall
comply with Section R311.2.2.
4. At openings around vents, pipes, ducts, cables and wires
at ceiling and floor level, with an approved material to
resist the free passage of flame and products of combustion.
5. For the fireblocking of chimneys and fireplaces, see Section
R1003.19.


2.3. Return-air inlets shall not be located
within 10 feet (3048 mm) of any appliance
firebox or draft hood in the same
room or space.

3. Rooms or spaces containing solid-fuel burning
appliances, provided that return-air inlets are
located not less than 10 feet (3048 mm) from
the firebox of such appliances.

 

[Don2222]

IRC 2003

R602.8 Fireblocking required. Fireblocking shall be provided
to cut off all concealed draft openings (both vertical and horizontal)
and to form an effective fire barrier between stories, and
between a top story and the roof space. Fireblocking shall be
provided inwood-frame construction in the following locations.
1. In concealed spaces of stud walls and partitions, including
furred spaces and parallel rows of studs or staggered
studs; as follows:
1.. Vertically at the ceiling and floor levels.
2. At all interconnections between concealed vertical and
horizontal spaces such as occur at soffits, drop ceilings
and cove ceilings.
3. In concealed spaces between stair stringers at the top and
bottom of the run. Enclosed spaces under stairs shall
comply with Section R311.2.2.
4. At openings around vents, pipes, ducts, cables and wires
at ceiling and floor level, with an approved material to
resist the free passage of flame and products of combustion.
5. For the fireblocking of chimneys and fireplaces, see Section
R1003.19.


2.3. Return-air inlets shall not be located
within 10 feet (3048 mm) of any appliance
firebox or draft hood in the same
room or space.

3. Rooms or spaces containing solid-fuel burning
appliances, provided that return-air inlets are
located not less than 10 feet (3048 mm) from
the firebox of such appliances.

BeGreen

The heated air vents supplying upstairs with heat have nothing to do with RETURN AIR or the Fire Blocking of stud cavities!

Thanks

 

[pring7]

What difference is this kind of ductwork than the ductwork that moves hot air from my heat pump? Is the issue that the fire wall is breached? I can’t see much difference between breaching it with an insulated duct vs. a through the wall fan.

 

[pring7]

I think I have enough space to meet the 10 foot rule with this actually.

 

[begreen]

IRC 2003

R602.8 Fireblocking required. Fireblocking shall be provided
to cut off all concealed draft openings (both vertical and horizontal)
and to form an effective fire barrier between stories, and
between a top story and the roof space. Fireblocking shall be
provided inwood-frame construction in the following locations.
1. In concealed spaces of stud walls and partitions, including
furred spaces and parallel rows of studs or staggered
studs; as follows:
1.. Vertically at the ceiling and floor levels.
2. At all interconnections between concealed vertical and
horizontal spaces such as occur at soffits, drop ceilings
and cove ceilings.
3. In concealed spaces between stair stringers at the top and
bottom of the run. Enclosed spaces under stairs shall
comply with Section R311.2.2.
4. At openings around vents, pipes, ducts, cables and wires
at ceiling and floor level, with an approved material to
resist the free passage of flame and products of combustion.
5. For the fireblocking of chimneys and fireplaces, see Section
R1003.19.


2.3. Return-air inlets shall not be located
within 10 feet (3048 mm) of any appliance
firebox or draft hood in the same
room or space.

3. Rooms or spaces containing solid-fuel burning
appliances, provided that return-air inlets are
located not less than 10 feet (3048 mm) from
the firebox of such appliances.

BeGreen

The heated air vents supplying upstairs with heat have nothing to do with RETURN AIR or the Fire Blocking of stud cavities!

Thanks

They have everything to do with the migration and containment of fire and smoke and slowing it down between floors.

FWIW, have you asked Travis about your setup?

 

[Don2222]

IRC 2003

R602.8 Fireblocking required. Fireblocking shall be provided
to cut off all concealed draft openings (both vertical and horizontal)
and to form an effective fire barrier between stories, and
between a top story and the roof space. Fireblocking shall be
provided inwood-frame construction in the following locations.
1. In concealed spaces of stud walls and partitions, including
furred spaces and parallel rows of studs or staggered
studs; as follows:
1.. Vertically at the ceiling and floor levels.
2. At all interconnections between concealed vertical and
horizontal spaces such as occur at soffits, drop ceilings
and cove ceilings.
3. In concealed spaces between stair stringers at the top and
bottom of the run. Enclosed spaces under stairs shall
comply with Section R311.2.2.
4. At openings around vents, pipes, ducts, cables and wires
at ceiling and floor level, with an approved material to
resist the free passage of flame and products of combustion.
5. For the fireblocking of chimneys and fireplaces, see Section
R1003.19.


2.3. Return-air inlets shall not be located
within 10 feet (3048 mm) of any appliance
firebox or draft hood in the same
room or space.

3. Rooms or spaces containing solid-fuel burning
appliances, provided that return-air inlets are
located not less than 10 feet (3048 mm) from
the firebox of such appliances.

BeGreen

The heated air vents supplying upstairs with heat have nothing to do with RETURN AIR or the Fire Blocking of stud cavities!

Thanks

They have everything to do with the migration and containment of fire and smoke and slowing it down between floors.

FWIW, have you asked Travis about your setup?

If the heat coming out of pellet stoves was contaminated or contained smoke or fire then we could not have them in our living rooms or homes!

I did find this in NFPA 211
12.2.3 Solid fuel-burning appliances shall not be installed in
any location where gasoline or any other flammable vapors or
gases are present.
12.2.4 Solid fuel-burning appliances shall not be installed in
any garage.
12.3 Air for Combustion and Ventilation.
12.3.1 Solid fuel-burning appliances shall be installed in a
location and manner so as to provide ventilation and combustion
air supply to allow proper combustion of fuel, chimney
draft, and maintenance of safe temperatures.

So we cannot have a pellet stove or wood stove in our garage because our cars have gas in their tanks!! But wood sheds are OK !!

As far as Travis goes, they probably do not recommend or disapprove as in the case of J-Takeman's stove manuals where ducting was removed.

However in the Ecotek Elana and Veronica Wood Pellet stoves they have ducting connections right in the back!! So there Cannot be a Fire Code against that or they could not make them!!

 

[94ranger55]

WEll back to the question ...yes this type of system does work very well I built mine last winter ! I will tell you what I am a lot warmer! Also I checked with my issurance and local fire department and said go ahead ! If you can find a way to keep your family warm, house warm and save money DO IT !

 

[woodgeek]

We have this debate about ducting air from stoves every once and a while....

Case 1: The OP wants to suck in hot stratified air from the top of his stove room, and blow it around his house. Presumably the inlet is at a respectable distance from the stove. The upside of this is that there is no cosmetic issue, and the only concern would be delivering CO to the bedrooms in some (highly unlikely) fault condition--which can be readily addressed by multiple CO alarms in the bdrms. The downside is that since the air being moved is cooler to begin with, he needs a bigger fan, bigger ducts, more duct insulation and higher operating costs (for the fan draw).

Case 2: The guy in https://www.hearth.com/talk/threads/67884/ ducted the outlet of his basement pellet stove. He did several good things in his post: (1) he started with a disclaimer that he was NOT recommending that others (i.e. newbs and fools) do something similar (2) he upsized the CFM on his blowers to reduce the delivery temps and (3) he was using a pellet stove, which do not have 'overfire' fault states, unlike regular stoves. The OP in that thread seemed to understand the issues, and was basically modd'ing his pellet stove to be more like a pellet furnace (by increasing the CFM) at the start. And it seems the BG let him be.

Case 3: Don is doing something a lot like Case 2, but he is not upsizing the CFM, and is sharing his excitement and asserting safety rather than disclaiming it to the newbs. The result, BG came down on him.

IMO, because of the lack of overfire I am much less concerned with ducting pellet stoves that I have been about ducting regular woodstoves. In the latter case, the ducting and register temps could be fine in normal use, but spike dangerously in an overfire/fault condition, which has happened to all of us with woodstoves at one time or another.

I don't really care for Don's argument that his arrangement used to be in the manual, and that similar units allow such hookups, or have recently, or that there is such a thing as a pellet furnace, and he is just making one. The bottom line is that the stove hardware we use is carefully engineered, constructed and inspected afterward for safety. If it not in the manual, it is not warrantied as safe by the manufacturer. You can rail about companies being too skittish about liability, but I for one am going to go with their instincts here. If the OEM doesn't suggest using their stove as a pellet furnace, then don't use it as a pellet furnace. I think Don's point actually makes the case--the manufacturer took the ducting suggestion OUT of the manual. Not a good endorsement of the practice.

All that said, I don't think Don is going to burn down his house, he is just one step lower down a slippery slope than the Case 2 guy, and should not be encouraging others to do the same unless they have a very good undertstanding of the engineering.

 

[DexterDay]

IRC 2003

R602.8 Fireblocking required. Fireblocking shall be provided
to cut off all concealed draft openings (both vertical and horizontal)
and to form an effective fire barrier between stories, and
between a top story and the roof space. Fireblocking shall be
provided inwood-frame construction in the following locations.
1. In concealed spaces of stud walls and partitions, including
furred spaces and parallel rows of studs or staggered
studs; as follows:
1.. Vertically at the ceiling and floor levels.
2. At all interconnections between concealed vertical and
horizontal spaces such as occur at soffits, drop ceilings
and cove ceilings.
3. In concealed spaces between stair stringers at the top and
bottom of the run. Enclosed spaces under stairs shall
comply with Section R311.2.2.
4. At openings around vents, pipes, ducts, cables and wires
at ceiling and floor level, with an approved material to
resist the free passage of flame and products of combustion.
5. For the fireblocking of chimneys and fireplaces, see Section
R1003.19.


2.3. Return-air inlets shall not be located
within 10 feet (3048 mm) of any appliance
firebox or draft hood in the same
room or space.

3. Rooms or spaces containing solid-fuel burning
appliances, provided that return-air inlets are
located not less than 10 feet (3048 mm) from
the firebox of such appliances.

BeGreen

The heated air vents supplying upstairs with heat have nothing to do with RETURN AIR or the Fire Blocking of stud cavities!

Thanks

They have everything to do with the migration and containment of fire and smoke and slowing it down between floors.

FWIW, have you asked Travis about your setup?

If the heat coming out of pellet stoves was contaminated or contained smoke or fire then we could not have them in our living rooms or homes!

I did find this in NFPA 211
12.2.3 Solid fuel-burning appliances shall not be installed in
any location where gasoline or any other flammable vapors or
gases are present.
12.2.4 Solid fuel-burning appliances shall not be installed in
any garage.
12.3 Air for Combustion and Ventilation.
12.3.1 Solid fuel-burning appliances shall be installed in a
location and manner so as to provide ventilation and combustion
air supply to allow proper combustion of fuel, chimney
draft, and maintenance of safe temperatures.

So we cannot have a pellet stove or wood stove in our garage because our cars have gas in their tanks!! But wood sheds are OK !!

As far as Travis goes, they probably do not recommend or disapprove as in the case of J-Takeman's stove manuals where ducting was removed.

However in the Ecotek Elana and Veronica Wood Pellet stoves they have ducting connections right in the back!! So there Cannot be a Fire Code against that or they could not make them!!

Don, What BeGreen meant (I believe), Is IF?? IF?? If a Fire started, You cannot have random holes going through your floor or walls. The easier it is for a fire to get air, the faster and hotter it will burn.. That is what that code means. It is designed to "Slow" your house from burning down. If, it were to catch fire (God Forbid).

Sorry to interrupt this thread. But code is code. If your Fire Marshall AND Your Insurance agent will pass it, Good for you. But this is a Code Violation. Every set-up is different. If using "Existing" Ducts and your adding in-line fans. May not be that big a deal. Just wire it up, and put a Rheostat on it. Its random holes and added ducts that end into "Nothing", that mitigate Fires.

 

[Don2222]

We have this debate about ducting air from stoves every once and a while....

Case 1: The OP wants to suck in hot stratified air from the top of his stove room, and blow it around his house. Presumably the inlet is at a respectable distance from the stove. The upside of this is that there is no cosmetic issue, and the only concern would be delivering CO to the bedrooms in some (highly unlikely) fault condition--which can be readily addressed by multiple CO alarms in the bdrms. The downside is that since the air being moved is cooler to begin with, he needs a bigger fan, bigger ducts, more duct insulation and higher operating costs (for the fan draw).

Case 2: The guy in https://www.hearth.com/talk/threads/67884/ ducted the outlet of his basement pellet stove. He did several good things in his post: (1) he started with a disclaimer that he was NOT recommending that others (i.e. newbs and fools) do something similar (2) he upsized the CFM on his blowers to reduce the delivery temps and (3) he was using a pellet stove, which do not have 'overfire' fault states, unlike regular stoves. The OP in that thread seemed to understand the issues, and was basically modd'ing his pellet stove to be more like a pellet furnace (by increasing the CFM) at the start. And it seems the BG let him be.

Case 3: Don is doing something a lot like Case 2, but he is not upsizing the CFM, and is sharing his excitement and asserting safety rather than disclaiming it to the newbs. The result, BG came down on him.

IMO, because of the lack of overfire I am much less concerned with ducting pellet stoves that I have been about ducting regular woodstoves. In the latter case, the ducting and register temps could be fine in normal use, but spike dangerously in an overfire/fault condition, which has happened to all of us with woodstoves at one time or another.

I don't really care for Don's argument that his arrangement used to be in the manual, and that similar units allow such hookups, or have recently, or that there is such a thing as a pellet furnace, and he is just making one. The bottom line is that the stove hardware we use is carefully engineered, constructed and inspected afterward for safety. If it not in the manual, it is not warrantied as safe by the manufacturer. You can rail about companies being too skittish about liability, but I for one am going to go with their instincts here. If the OEM doesn't suggest using their stove as a pellet furnace, then don't use it as a pellet furnace. I think Don's point actually makes the case--the manufacturer took the ducting suggestion OUT of the manual. Not a good endorsement of the practice.

All that said, I don't think Don is going to burn down his house, he is just one step lower down a slippery slope than the Case 2 guy, and should not be encouraging others to do the same unless they have a very good undertstanding of the engineering.

Hello Woodgeek

I have an idea. We should have a document up top that addresses this issue, that the moderators can refer to in the future.

Stating that this is against code, when it has not been proven, is not a way to settle the debate.
Codes vary from state to state and listing all the states and their exact code should not be this forum's responsibility!!

We should however assure members that Hearth.com is not recommending this procedure and list the cautions and engineering to consider if undergoing this type of modification.

This would have everyone on the same page and protect hearth.com and it's members.

So a document written with the issues at this time and a disclaimer would be really nice to have!

P.S.
I did not need a higher CFM fan because I only ducted half the stove output to half as many registers as the other guy.

Also the inline blower was added to make it very efficient and yes I do have a CO Alarm.

 

[begreen]

Most states adhere to the international residential code. The reason it is a violation of code is the same reason cutting holes through floors need fire dampers - safety. A furnace, wood stove or other ducted appliance has high temp limit switches to cut off the appliance if an over-temp situation is detected. Add a fusible link damper and a high temp limit switch if you want to make this setup safe.

Send a picture to your insurance company to be sure it's covered. Ask the stove manufacturer if it is acceptable and within warranty requirements.

 

[Don2222]

Hello Dexter

Ductwork is not a random hole in the floor. It is an enclosed path to a heating register.

If you know the history, The reason for the fire block code was to improve construction. I grew up in a large victorian built in 1890. In those days the stud cavity was open from the 1st floor all the way to the attic. So the code was written to add a horizontal 2x4 across the studs for each floor as a fire block. It would stop a first floor fire from quickly spreading to the attic. In these modern times the insulation in the walls will also help the fire from spreading but that is the true reason for the code. Noone can or should interpret that to mean something else. If there is another issue then the code books are updated with a new code for that issue!

Also I believe there is a code requirement in NFPA 211 for the the max temperature of the return air to be no more than 80 degrees. So having a document to refer to may help us all out here!

 

[Don2222]

Most states adhere to the international residential code. The reason it is a violation of code is the same reason cutting holes through floors need fire dampers - safety. A furnace, wood stove or other ducted appliance has high temp limit switches to cut off the appliance if an over-temp situation is detected. Add a fusible link damper and a high temp limit switch if you want to make this setup safe.

Send a picture to your insurance company to be sure it's covered. Ask the stove manufacturer if it is acceptable and within warranty requirements.

Hello BeGreen

As a matter of fact the heat ducting I used has a damper in each trunk line. See yellow arrows below. Also due to so much horizontal ducting a fire could NEVER spread to the upper floors thru the ducts, it just would not even travel thru the ducts!!

Thanks

 

[begreen]

Is that a fusible link damper? From the picture it looks like a simple key balancing damper which is not the same animal.

What did your stove and insurance companies say?