Looking for quiet blower behind stove inside fireplace

[KingPoland]

After a lot of reading and digging for information for a quiet blower I can use with my setup, I'm no closer to having an answer.

The fan (Englander AC-16) that came with my stove (Englander NC-13) doesn't have enough clearance behind the stove and it is very loud. While I currently have a fan pointing at the side of the wood stove to move some air, I think it would be more efficient to have a fan or blower behind the stove blowing air up to the block off plate and then out. I'd likely need to create some sort of mount to rest it on the ground, but I have confidence I can figure that out. What I don't know is what fan or blower I can use that is quiet (targeting 50 dB or less at 5 feet distance) but still moves air (preferably 100+ cfm) . Having the ability for the fan to turn on automatically when the stove gets up to temp would be nice, but not essential.

Looking for recommendations for a quiet blower, or feedback if you have a better idea. Picture of my install attached.

 

[SidecarFlip]

Quiet and good air movement don't exist. If you want good circulation the vert principle of air movement creates noise from turbulence created by the fan blades. More movement, more noise. It's the way it ta and always has been. Good luck finding something and if you do, tell the world, I'm sure a bunch of burners would love to know.

 

[jetsam]

Consider insulating the fireplace if it's an exterior chimney, that is eating most of your heat production. That is a very tough position for a stove to heat from.

Insulate above the blockoff too, if it's not already.

 

[begreen]

Quiet and good air movement don't exist. If you want good circulation the vert principle of air movement creates noise from turbulence created by the fan blades. More movement, more noise. It's the way it ta and always has been. Good luck finding something and if you do, tell the world, I'm sure a bunch of burners would love to know.

Actually they do coexist. The average 12" table fan running on low or medium speed is very quiet and moving a lot of air. On high speed some of these stoves move 1200 cfm.
You might try pointing a table fan on the floor, following the side angle of the fireplace to blow cool air in on one side and hot out the other. That works for some folks.

 

[SidecarFlip]

I have to say I do just that (table fan on top the stove... Always have. I keep the room air blower in the stove on low and run the fan on top. Works pretty well actually. Looked at those little Sterling thermal engine powered fans but they don't appear to be efficient air movers and the price is pretty steep too.

 

[Mech e]

I have to say I do just that (table fan on top the stove... Always have. I keep the room air blower in the stove on low and run the fan on top. Works pretty well actually. Looked at those little Sterling thermal engine powered fans but they don't appear to be efficient air movers and the price is pretty steep too.

I think those fans use thermoelectric (Peltier) technology.

 

[SidecarFlip]

I think those fans use thermoelectric (Peltier) technology.

You could be right. All I know is they aren't much for the asking price.

 

[Das Jugghead]

To the OP if your aim is to get more usable heat out of your stove I very strongly recommend insulating the fireplace and installing a block off plate. I have a similar set up to yours and when I insulated and installed a block off plate it made a very significant improvement in my usable heat production.

Insofar as a quiet fan I have a small 6" fan on the hearth pointing up at an angle across the face of the fireplace opening more for moving the hot air away from the mantel above the fireplace opening. The small fan is always on except for reloading or cleaning out ash. For burns where the stove is really cranking I have an additional 12" located about 6' away that is on a cheap mechanical timer. When I employ the additional fan I run it about an hour. There have been times where I had an exceptionally excellent batch of wood and I have run the fan for 2 hours.

 

[Easy Livin’ 3000]

After a lot of reading and digging for information for a quiet blower I can use with my setup, I'm no closer to having an answer.

The fan (Englander AC-16) that came with my stove (Englander NC-13) doesn't have enough clearance behind the stove and it is very loud. While I currently have a fan pointing at the side of the wood stove to move some air, I think it would be more efficient to have a fan or blower behind the stove blowing air up to the block off plate and then out. I'd likely need to create some sort of mount to rest it on the ground, but I have confidence I can figure that out. What I don't know is what fan or blower I can use that is quiet (targeting 50 dB or less at 5 feet distance) but still moves air (preferably 100+ cfm) . Having the ability for the fan to turn on automatically when the stove gets up to temp would be nice, but not essential.

Looking for recommendations for a quiet blower, or feedback if you have a better idea. Picture of my install attached.

View attachment 268461

Could you get an angled adaptor and move the stove out enough to fit the englander blower in? I see you already have a block off plate (well done), and you might have to enlarge the center hole, on top of all the work to pull the stove and reattach the liner with the new angled adaptor, but that would sure solve your problem.

Another thought- maybe shorter legs would give you enough play to get the blower in there? I don't know if they are available from englander, or if that would even help. This would also involve enlarging the hole in the block off plate.

I will add my 2 cents about insulating the sides and back of the fireplace- it will help a lot. I'd use rigid rock wool.

 

[EbS-P]

100 CFM at 50 dB might be unobtainable for stove blowers.

This is what I have just sitting on the floor behind my stove. On low it has a bit of a rattle, but it’s unobtrusive. I run it on low 90% of the time. On low it will drop stove top temps by 50 dF in 1 minute . Couple reasons I chose this one is that it intakes on both sides, has rubber feet( but they tend to fall out). Came with a rheostat and magnet thermal switch. Maybe an oem version might be quieter?

You might be able to find a fan that can do it but is it designed to withstand and operate for extended periods at high temps. ( I was thinking about the really big computer fans 200-300+ mm but I bet they don’t last long.)


Durablow GFK-160 Fireplace Stove Blower Complete Kit for Lennox, Superior, Heat N Glo, Hearth and Home, Quadra Fire, Regency, Royal, Jakel, Nordica, Rotom Amazon product ASIN B00HJ82S6U

 

[DBoon]

Fan blade tip velocity creates a lot of noise - so a larger diameter fan blade running at lower RPMs to push the same air as a smaller fan at higher RPMs is always going to be a lot quieter (to begreen's point)

 

[Easy Livin’ 3000]

What about those bladeless dyson blowers? I've seen them, have no idea how they work, and they are expensive. But I'm curious.

 

[brenndatomu]

You might try pointing a table fan on the floor, following the side angle of the fireplace to blow cool air in on one side and hot out the other. That works for some folks.

I tried that...worked pretty well...

 

[moresnow]

When placing a remote/separate fan behind a tube stove think about this. Where is your secondary air inlet located? Most of these inlets get waaay plenty of air as is without having pressurized forced air fed into them! Lesson learned a number of years ago I admit.

 

[jetsam]

OP wants more heat, 75%+ is currently radiating into masonry. Can't fix that with a fan.

If it's an interior chimney, most of that heat stays in the house. If it's not, it doesn't.

 

[KingPoland]

Consider insulating the fireplace if it's an exterior chimney, that is eating most of your heat production. That is a very tough position for a stove to heat from. Insulate above the blockoff too, if it's not already.

jetsam, I do have an exterior chimney. I did build a block off plate and also stuffed half the bag of rockwool up the chimney from the smoke shelf to whats left of the old fireplace damper, so heat loss up the chimney is fairly minimal now. I did not consider insulating the fireplace though.

To the OP if your aim is to get more usable heat out of your stove I very strongly recommend insulating the fireplace and installing a block off plate. I have a similar set up to yours and when I insulated and installed a block off plate it made a very significant improvement in my usable heat production.

I imagine I could use my leftover steel flashing and rockwool to do that similar to what Das Jugghead and Easy Livin’ 3000 did. Any good write-ups out there on insulating the fireplace?

You might try pointing a table fan on the floor, following the side angle of the fireplace to blow cool air in on one side and hot out the other. That works for some folks.

begreen and SidecarFlip, I'm currently using a small table fan pointing at the side of the wood stove from 3 feet away. The fan moves a lot of air and is quiet, but I have to wonder if putting something behind the stove might do better at moving air.

Could you get an angled adaptor and move the stove out enough to fit the englander blower in? I see you already have a block off plate (well done), and you might have to enlarge the center hole, on top of all the work to pull the stove and reattach the liner with the new angled adaptor, but that would sure solve your problem.

Another thought- maybe shorter legs would give you enough play to get the blower in there? I don't know if they are available from englander, or if that would even help. This would also involve enlarging the hole in the block off plate.

I will add my 2 cents about insulating the sides and back of the fireplace- it will help a lot. I'd use rigid rock wool.

Easy Livin’ 3000, I should have used an angled adapter when installing - would have made life easier then in now. Too much hassle to change at the moment though. I could probably stick the Englander blower behind the stove pointing up to the block off plate to test it out, but even on low that thing is really loud. But maybe not as loud with a stove in the way?

You might be able to find a fan that can do it but is it designed to withstand and operate for extended periods at high temps. ( I was thinking about the really big computer fans 200-300+ mm but I bet they don’t last long.)

Durablow GFK-160 Fireplace Stove Blower Complete Kit for Lennox, Superior, Heat N Glo, Hearth and Home, Quadra Fire, Regency, Royal, Jakel, Nordica, Rotom Amazon product ASIN B00HJ82S6U

EbS-P, I'll take a look at the Durablow GFK-160. I also thought about computer fans, but also concerned about the heat even if closer to the base of the woodstove.

 

[Seasoned Oak]

All the wood stove fans iv ever had were squirrel cage fans which are very quiet themselves but rattled at the mounting point. Changing the fan speed usually works to find the low vibration point and stop the rattle.

 

[jetsam]

jetsam, I do have an exterior chimney. I did build a block off plate and also stuffed half the bag of rockwool up the chimney from the smoke shelf to whats left of the old fireplace damper, so heat loss up the chimney is fairly minimal now. I did not consider insulating the fireplace though.

I imagine I could use my leftover steel flashing and rockwool to do that similar to what Das Jugghead and Easy Livin’ 3000 did. Any good write-ups out there on insulating the fireplace?

Your problem is that your stove is radiating directly into an infinite heat sink (masonry which is exposed to the outdoors and the earth both).

Your ideal solution involves some construction (build out the hearth, move the stove out of the fireplace, make a new hole in the chimney higher up for the flue... or just run the flue through the roof).

I doubt you want to do all that, so second-best is insulating the fireplace. I think in your case it will be a large difference in the heat output you perceive from the stove. And yes, we have a couple great writeups on that topic, my favorite being this one by mellow.

I know it looks crude at first but keep following the thread... he eventually finishes it using cement board painted with stove paint, and it looks nice.

And when he says it made a big difference for him.... that is with an insert that is designed not to radiate much heat to the sides and back! Your improvement should be even better.

 

[KingPoland]

Your problem is that your stove is radiating directly into an infinite heat sink (masonry which is exposed to the outdoors and the earth both).

Your ideal solution involves some construction (build out the hearth, move the stove out of the fireplace, make a new hole in the chimney higher up for the flue... or just run the flue through the roof).

I doubt you want to do all that, so second-best is insulating the fireplace. I think in your case it will be a large difference in the heat output you perceive from the stove. And yes, we have a couple great writeups on that topic, my favorite being this one by mellow.

I know it looks crude at first but keep following the thread... he eventually finishes it using cement board painted with stove paint, and it looks nice.

And when he says it made a big difference for him.... that is with an insert that is designed not to radiate much heat to the sides and back! Your improvement should be even better.

That was quite a thread, but a lot of interesting variations there. Will have to take some time to read more. One advantage my fireplace has is that it is constructed with several layers of air gapped brick (which I found out when coring a hole for outside air), so theoretically that makes it less of a heatsink.

 

[begreen]

100 CFM at 50 dB might be unobtainable for stove blowers.

There are axial muffin fans that meet that criteria.

https://www.grainger.com/product/HOFFMAN-Standard-Square-Axial-Fan-32FL50

 

[agonyzhou]

I use this:

AIRBLAZE T14, Fireplace Blower Fan 14" with Temperature and Humidity Controller

Your source to create smart growing systems with components including advance grow tents, inline fans, clip-on fans, LED grow lights, and UIS™ controllers.

www.acinfinity.com

I actually remove the whole blower assembly that come with my flush insert and put this fan in it's place. It is an DC blower controlled by PWM and electronic temperature sensor. I tape the sensor in roughly the same place as the snapdisc before. Obviously mounting holes don't match up but with HVAC tape and some extra padding I made it fit.

It is rated at 200CFM but I don't think it can deliver 200 CFM in my stove; maybe 100? It feels like somewhere between the low and high settings of the original blower. Noise wise there is some improvement but not a whole lot. However now I gain the controllability without keeling on the ground. It is precisely temperature controlled so it spins faster when it gets hot and spins slower when it is cooler. I can make the sensor spot exactly 113F +- 2F for 90%+ of the my burning cycle. With the old snapdisc controlled AC fan, you set a speed and the fan is either on or off; and the snapdisc has a huge (like 30F) temperature hysteresis so there is a lot of temperature variety.

 

[EbS-P]

This one might be promising. They claim 1.6 sones. My quick googling says that less than 50 dB. Probably needs a mount or feet of some kind.

Tjernlund FB15DLX Fireplace Blower Motor with Speed Control & Adjustable Thermal Switch, 160 CFM, 15" Amazon product ASIN B00FH7KMRW

 

[KingPoland]

I use this:

AIRBLAZE T14, Fireplace Blower Fan 14" with Temperature and Humidity Controller

Your source to create smart growing systems with components including advance grow tents, inline fans, clip-on fans, LED grow lights, and UIS™ controllers.

www.acinfinity.com

I actually remove the whole blower assembly that come with my flush insert and put this fan in it's place. It is an DC blower controlled by PWM and electronic temperature sensor. I tape the sensor in roughly the same place as the snapdisc before. Obviously mounting holes don't match up but with HVAC tape and some extra padding I made it fit.

It is rated at 200CFM but I don't think it can deliver 200 CFM in my stove; maybe 100? It feels like somewhere between the low and high settings of the original blower. Noise wise there is some improvement but not a whole lot. However now I gain the controllability without keeling on the ground. It is precisely temperature controlled so it spins faster when it gets hot and spins slower when it is cooler. I can make the sensor spot exactly 113F +- 2F for 90%+ of the my burning cycle. With the old snapdisc controlled AC fan, you set a speed and the fan is either on or off; and the snapdisc has a huge (like 30F) temperature hysteresis so there is a lot of temperature variety.

Wow. That thing looks super fancy. It may be the one.

 

[kennyp2339]

Change out the stove to a proper insert and you'll have the convective jacket that you need with a blower in the front of the stove that will run quieter then the blowers englander supplies.

 

[Easy Livin’ 3000]

Change out the stove to a proper insert and you'll have the convective jacket that you need with a blower in the front of the stove that will run quieter then the blowers englander supplies.

I was gonna say this also, it is the best move. But, its a $1,099k solution.