Hearthstone Heritage. Does a blower increase efficiency?

[TMonter]

The formula to calculate heat transfer has 2 numbers to use, one if depending on natural convection and another if there’s wind blowing & turbulance. The one with wind & turbulance works out to transfer about 3x more heat than natural. Take for example a spoon full of soup that’s too hot. You can either hold it up and wait for it to cool naturally, or you can blow on it. Blowing on it significantly improves the heat transfer.

Yeah, you do get more heat transfer initially with turbulent flow (The number you're thinking of is the Reynolds Number) but overall you can only move as much heat as the stove is producing. Additionally I'm thinking from the perspective of keeping the chimney temperature at least 300 to prevent creosote formation you don't want to remove too much heat from the stove. I have a TC in my chimney and temperature usually hangs around 290-325 at the pipe exit when I have the stove burning on low. I almost never need to turn the stove up unless the temp outside drops below 25 F.

I guess I'm just used to running the stove 24/7 and never really need to re-heat the house once it's been heated up. You guys make a good case for having a blower in some situations. I would still recommend most stove owners try the stove without the blower and install the blower after the fact if they find they need it. Blowers usually don't change in price much if ordered separately from the stove, the one for my Quad was the same price if ordered with the stove or separately.

 

[Highbeam]

I hate it when people say "simple" thermodynamics. I took thermo in school and did very well but it wasn't what I would refer to as simple. Bah, maybe you all are just smarter than me.

Now my question... Does a turned off blower actually block the air channels enough to slow the flow down. I mean, just turning my blower off can't be an accurate test to see what life would be like without a blower. My Lopi insert makes much much less heat without the blower engaged but whether the blower is on low or high speed makes no difference. I also use a ceiling fan which I find does a great job of making the whole room top to bottom the same temp.

I wish I could turn all the fans off. I really enjoy a quiet fire with the only sounds being the suck of air into the stove and the occasional pop of the cedar. All the fans humming and spinning takes a lot out of it. I have flat ceilings so teh spinning fan is right there.

 

[TMonter]

Is unbolting the fan from the insert a simple procedure? If so you might just remove the fan entirely and give it a shot. I've convinced two other friends who bought inserts to try it without the fan and both have found they didn't need them.

As for thermo being simple I guess I have a perspective from working with it day in and day out.

 

[Rick]

Does anyone actually have a blower on a Heritage, or any other freestanding stove? I'm not too interested in increasing efficiency, I just wonder if they move the air enough to make them worthwhile. I've been kicking around the idea of getting one.

 

[drbond]

Heritage with rear heat shield and blower and I don't know about all the thermodynamic stuff, but I can tell you that with stove at running temp (400-500) the adjacent rooms are warmer with the fan running than with it off.

Bondo©

 

[DriftWood]

Got the wife approval down. For me I was thinking about my back bedroom where I could get it warmer before I retire at night coil up the flexable duct and stick it in a closet.

I guess an electric blanket would more appealing from the wife standpoint and warmer

Straight out of a hot bath into a cold bed. No problem with a really thick Winter Goose Down Full baffler hi fill power comforter. Bed room temps 59 day , 49 or lower in the morning. When it gets really cold we put a Hudson's Bay blanket under the comforter. We also switch to the flannel sheets in winter. Thing is she will still throw the covers off 2-3 times at night as the flashes come and go.

 

[zeke7237]

I have a Harman TLC2000 burning nut coal, and I didn't have the fan the first year we burned (last year). I have the stove mounted in a hearth, so I don't have an ideal situation as far as circulation around the stove. I can definitely say in this case that it's much warmer with the stove running lower than last year. The problem is that it's also drying out the air much more dramatically causing sinus problems for my wife and I both. Rather than hijacking this one, I'll start a new thread asking about humidity issues and how people deal with them ..

 

[relax]

how about a thermal fan on a soap stone...ZZZin

 

[gweldgen]

We happen to have our Regency crosswise in a corner. We had enough safety clearance to place one of the upright oscillating fans that Walmart sells in the corner. We run it on low and it sweeps back and forth behind the stove pushing heat out but not cooling the firebox.

 

[LHKountryboy]

I admit I haven't really played with the soapstone heritage stove much so far as its still a warm fall, but short of scientific thermal dynamic studies, I have to say that atleast for my steel stove a fan DOES really help move some heat out into the room. Some might same I'm dogding a loaded gun, But I have plenty of rear clearance, so I have used a 20" box fan behind the big Schrader for about 15 years now, I have it hooked up to a bimetal furnace blower switch screwed to the upper rear side of the stove under the brass rail anchor screw with an air shield clipped to it . Blower switch was scavanged for free (turns on at about 150 degrees) but readily available, and the box fan $11.99 this time, (I have replaced it once. )

I have measured the air temps at several different points in the room and between that, the ceiling fan and an oscillating pedestal fan in the corner of the room about 15 feet away, I have usually about 5 degrees total temperature variation in the 30x20' "great room" . Previously at was more like 15 degrees. So I can attest to that fact that it does move heat and cool air around and help balance the ambient room temp.

But once again I have plenty of clearance and a 8x 10' brick wall back there behind the Schrader. I also have a probe thermometer, a magnetic rutland thermometer, and an " audible over fire alarm" ( remote probe oven style electronic thermometer) attached to my stack with a S/S 10" hose clamp on it.
So I have little doubt whats going on over there. May not be totally scientific or esthetic, but works well for me.

I'll likely build something a little "Prettier" for the Heritage, based on similar principles. Likely a low velocity squirrel cage fan inset into the hearth with a floor intake well away from the stove with a rear exhaust air wash behind and well above and way from above the air intake on the Heritage to blow cros the rear " heat shield" to some extent and move some of the heat up and out at an angle into the sun porch, as the Heritage is going to be a corner install.