Lets talk about integrated fans

[Labfriend]

The fan on my insert is louder than
I would like but it does move the heat out into the room.

 

[Poindexter]

My current stove (BK Ashford 30) has a factory fan kit that blows air between the cast iron cladding and the inner welded steel firebox. The air gap looks to be +/- half an inch, average. My previous stove was a welded steel non cat with no cladding. On that one I had one of the heat operated fans with no electrical cord to it sitting on top of the stove.

With no fan at the stove, at my house, walking closer and closer to the stove, the air got hotter and hotter. And hotter. On either with the fans running the room would be warmer away from the stove, and I could stand closer to the stove without getting uncomfortably hot.

I also run a gentle convection loop along my hallway to the bedrooms. I use a regular 24" box fan on the floor, on low, scooting cool air along the floor of the hallway towards the woodstove.

With both wood burners, if I had a fan on the stove running I got more heat down the hallway to the bedrooms with the box fan on the floor then I could get with just the box fan on the floor and no fan on the stove.

With kids home, I don't notice the noise of the factory fan kit on my BK. If it just the wife and me watching television in the stove room I do turn the fan down to low, and then ooch it back up towards medium when we are headed down the hall to bed.

 

[SpaceBus]

My Osburn does it, so does my parents PE Super 27. Conclusion we have come to is it has to do with the temperature differential between the firebox and sheet metal jackets causing different forces within the sheet metal, which seems to change the resonant frequencies of the material. Usually changing the fan speed on mine makes it go away, but once and a while it stays from low to high, in which case a gentle open palm hit to the vibrating sheet metal usually stops it.

I think manufacturers are stuck in a hard place on fans though, Ideally a larger lower speed fan would make it quieter, but then where do they put it, particularly on inserts.

I guess it's a bit like a harmonica at that point. The sheet metal ever so slightly changes shape and now the whole "sound chamber" is different.

 

[buc74]

I took the surround off my Buck 74 insert and pull it out a few more inches. So far it seems to warm the house just fine without the blower on. More like a free stander I guess. We'll see how it goes when it gets colder out. I was also thinking of setting one of those heat powered fans on top now that I have like 12" of stove sticking out. The surround will be staying off, seems counter productive with it on. Plus I really like how it looks now.