Hearthstone Heritage. Does a blower increase efficiency?

[rubantin]

Does a blower increase efficiency?

Just wondering if it is worth the $200 price tag?

Right now I have a fan blowing on the stove... kind of noisy... I suppose the squirrel cage hearthstone has would be quieter and more effective.

Comments invited..

Thanks

 

[MountainStoveGuy]

No, your best fan is a celing fan.

 

[DonCT]

Don't have it, so I can't give advice to that. But I've found that I don't really need the blower or a fan. My place just heats nicely with the convection

 

[rubantin]

ok... I am a science teacher... so It seems that a fan would cool the surface and encorage transfer of energy from the inside... but don't know if that makes sense...

Thanks

 

[MountainStoveGuy]

same thing a celing fan does, except it doenst cool the stove down and encourages more complete combustion.
there isnt much exchange to be had with soapstone stoves, they only run in the 450* range. You get better exchange on steel stoves that run in the 600-700* range. But in all cases, a celing fan is a fantastic circulator of heat.

 

[Roospike]

I use a fan on my freestanding wood stove on low or about 1/3 speed and it does a very nice job of "rolling heat" off the stove and the ceiling fan take it from there. With the fan / blower on the stove there is less of a hot spot in the stove area and it distributes the heat in a better fashion.

I bought a fan blower and placed it on the floor below the back of the wood stove facing up. Not a stove model to the stove buy works just as well and my cost was $99. on ebay.

 

[damien]

What about cast iron stoves? Do they transfer energy as well as steel stoves? And what kind of range do they normally run in?

 

[kevinmoelk]

Glad to see this thread going. I've been wondering if I should pony up the money for a blower on my stove. I think I could make one, but not sure of the requirements to do so. Need to do more research. Thus far, my stove is in the living room, which has a ceiling fan I run on high. I also have a box fan I run on low pushing air into the living room. The fans definately make a difference at distributing the heat to the rest of the home. I'm not sure if a blower would help all that much over my current system.

Spike, is that a dime under the leg of your stove? LOL, if so I did the same thing on my stove to level it out since the ceramic tile is textured. Great minds think alike.

-Kevin

 

[Roospike]

Sorry , no dime here. The legs of the Pacific Energy stoves ahd adjustable feet / bolts that adjust up and down to level the stove ........... must be the end of the foot / bolt you are seeing.

Search Ebay for "heat glo fan" and also "heat glo blower" , there are some good deals on there for around $99. .

 

[kevinmoelk]

Sorry , no dime here. The legs of the Pacific Energy stoves ahd adjustable feet / bolts that adjust up and down to level the stove ........... must be the end of the foot / bolt you are seeing.

Search Ebay for "heat glo fan" and also "heat glo blower" , there are some good deals on there for around $99. .

Thanks for the tip Spike. I inquired about the leveling kit for the Country stove I have and it was $15 bucks for some special washers and machine bolts. I only had one leg I needed to shim and a dime fit perfectly under it and is unseen, so I opted not to purchase the kit. So far it hasn't melted or walked away

-Kevin

 

[Corie]

wrench, I think I have a fan at home that would work for you, if ya want it of course.


I can snap some photos next time I'm home and I'll hook it up to a power supply and make sure it still runs smooth and quiet.

 

[rubantin]

Well... the stove shop guy told me that I will get more heat from the stove and that it would increase the efficiency... Now... what should I believe...lol

 

[MountainStoveGuy]

belive who you like, we have no vested intrest going along with our opinion.
Save your money and buy a celing fan.. i think its a waste of money to try to exchange heat off of a 400* surface. If you have a 600* steel stove... mabey.. but not soapstone.

ask him if its returnable if it doenst perform like he says it will.. my guess the answer will be no.

 

[philaphire]

Here's probably what the stove shop guy is thinking: Blowers get heat out and about into a room and could therefore make you feel warmer quicker and therefore possibly having you damper down quicker resulting in a longer burn. I was at a friends house the other day (granted this is a steel insert) and once the blower kicked on the room heated up nice and quick. WIthout it, I'm sure the stove would stay wide open and perhaps even fuel added! That or he's thinking - how much more money can I make :cheese:

remember - these are the same guys who tell you to turn your furnance fan on to circulate the heat throughout the house and we know that doesn't work!

 

[MountainStoveGuy]

steel inserts are alot differnt then a soapstone free standing stoves. Steel inserts require the blower to operate correctly, on soapstone stoves they do nothing but dry the air out.

 

[elkimmeg]

Hey Roo try this out say you got a flexible dryer vent and attached one to the blower the other end into a far reach leave it on the floor and draw the cool flor level air to the stove. Place a thermometer in that bedroon and watch it rise This work better than a box fan on the floor pointed at the stove to heat a remote room

 

[TMonter]

steel inserts are alot differnt then a soapstone free standing stoves. Steel inserts require the blower to operate correctly, on soapstone stoves they do nothing but dry the air out.

Not true, I have a Quadrafire 3100i (insert) that I purchased without the blower and it works just fine without the fans. Fans are only going to move heat further out into the room if you have convection issues around the stove. In most cases the fan that comes with the stove is a waste of money. Fans will not really improve stove efficiency unless you're running the stove too hot in the first place. In fact I've seen more problems caused by insert fans than anything else because they cool the stove too efficiently and the fire starts burning improperly.

Any insert with a properly designed shroud should not need a fan.

 

[MountainStoveGuy]

im a firm beliver in fans and inserts. So i respecfull disagree. A 3100 will work just fine without a blower, but it will work better with a blower. There is lots of exchange to be had on that top jacket that is buried back in the fireplace.

 

[TMonter]

im a firm beliver in fans and inserts. So i respecfull disagree. A 3100 will work just fine without a blower, but it will work better with a blower. There is lots of exchange to be had on that top jacket that is buried back in the fireplace.

Since you are already getting circulation through natural convection through that zone, you will get minimal or no additional heat with a blower. It's simple thermodynamics. You need two things:

Residence time of air
Temperature difference

more air means less residence time and lower exit air temperature. Total heat moved will be the same or close to the same (Except during initial warm-up).

You will be more efficient at moving heat away from the stove, but once the room is heated to temperature, a fan offers no benefit.

All inserts with a shroud will naturally pull air in at the low spots and exit at the high spots. When my 3100 is operating I can feel a breeze at the top air exit and I don't have a fan. What I have noticed is that placing a fan to blow air through the shroud does get air away from the stove more effectively especially when heating the house up from being cold.

 

[rubantin]

Hey Roo try this out say you got a flexible dryer vent and attached one to the blower the other end into a far reach leave it on the floor and draw the cool flor level air to the stove. Place a thermometer in that bedroon and watch it rise This work better than a box fan on the floor pointed at the stove to heat a remote room

great idea...however the wife would love a pipe runniing along the floor of her living room...lol

 

[elkimmeg]

Hey Roo try this out say you got a flexible dryer vent and attached one to the blower the other end into a far reach leave it on the floor and draw the cool flor level air to the stove. Place a thermometer in that bedroon and watch it rise This work better than a box fan on the floor pointed at the stove to heat a remote room

great idea...however the wife would love a pipe runniing along the floor of her living room...lol

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

 

[MountainStoveGuy]

im a firm beliver in fans and inserts. So i respecfull disagree. A 3100 will work just fine without a blower, but it will work better with a blower. There is lots of exchange to be had on that top jacket that is buried back in the fireplace.

Since you are already getting circulation through natural convection through that zone, you will get minimal or no additional heat with a blower. It's simple thermodynamics. You need two things:

Residence time of air
Temperature difference

more air means less residence time and lower exit air temperature. Total heat moved will be the same or close to the same (Except during initial warm-up).

You will be more efficient at moving heat away from the stove, but once the room is heated to temperature, a fan offers no benefit.

All inserts with a shroud will naturally pull air in at the low spots and exit at the high spots. When my 3100 is operating I can feel a breeze at the top air exit and I don't have a fan. What I have noticed is that placing a fan to blow air through the shroud does get air away from the stove more effectively especially when heating the house up from being cold.

Simple thermal dynamics or not, I think most folks would disagree with you. I tell my customers to run there fan on the lowest setting, and in this position i dont believe it cools the air down to much, and i would guarentee that the ambient temperture in back of the old firebox drops. Not that i matters, if you happy with you insert without a blower thats great!

 

[BurningIsLove]

I have the fan assembly on my DW. Leaving the different construction types aside, I have noticed a very beneficial effect from the fan, but I only use it at certain burn/house conditions. When the house is cold and I start a new fire, it takes a while before the rheostat on the fan is hot enough to engage the fan. But it takes even longer before the coal bed/2ndary burn chamber are hot enough to burn efficiently. During that time, the fan does a great job of starting a circulating pattern of warm air to adjacent rooms in the house. By the the time the reburner is ready, the radiant heat being given off by the stove is normally enough (cast iron, around 500+ degrees) without the fan.

Also on the really cold nights (below 10F) and the stove is operating efficiently in all respects, the fan does help keep the extreme corners of the house warm. It doesnt seem to impact efficiency when it's running.

 

[Rhone]

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.

To increase heat transfer the higher you keep the temperature difference and more turbulance you have, the more energy you transfer into the air. There's a solar product out there, called CanSolair which uses aluminum soda cans painted black with the tops & bottoms cut out stacked on each other to form long tubes. One of its secrets, is the shape of soda cans. They're not perfect smooth cylinders and stacked on top of each other they create turbulance in the air passing through them which increases the heat transfer making them more efficient than smooth cylinders.

So, not having blowers there's 2 strikes happening. One, is that you don't have as much turbulance so you're not getting as much heat transfer the other being that the higher the temperature difference the more transferred. Blowers maximize the temperature difference so you get more heat out of the fire. Inserts are also designed knowing the effect the blowers have on cooling and they're designed to compensate for that. I haven't seen a difference in how my insert burns with the blowers on or off. I feel the difference in how my insert heats my house with the blowers off, most of my heat goes out the flue and I have to burn significantly more wood and hotter fires to try to compensate for that, and it doesn't heat the house near as well or evenly. I basically feel like the wind is taken out of my sails when the power goes out. You can also compare it to the heating in your car. In my car, I can turn the heat on without the blowers and it doesn't heat very well. Maybe after 30 minutes the car may be warm. But, if I turn the blowers on with the heat, big difference particularly to occupants in the back.

A stove is not as easy to decide blowers because they always have a big temperature difference even without blowers being in the open, an insert is encased in a shroud which is encased in the fireplace. I think a ceiling fan is probably the safest bet with a stove, I've found stoves likely to overheat the room they're in. With a ceiling fan, not only do you increase air flow and turbulance around the stove you also cool the people in it so, you improve the transfer and improve the comfort of the occupants of the room. Though, I've seen it mentioned that some people have house layouts with a stove & ceiling fan where having the ceiling fan on prevents the heat from leaving the room, it just constantly recirculates the same air. Best in open floor plans & rooms without cathedral ceilings.

 

[WarmGuy]

My insert heats the room much more effectively with the fan on. No contest.

Each house/room is different. But Consumer Reports did some tests and concluded that a ceiling fan on low, whether pushing air up or down, caused the room to feel cooler because of the motion of the air agains the skin. For my house, this matches what I've observed. I use our ceiling fan to help distribute heat, but only when there's no one in the living room.