Wood consumption with fan on high

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JimA

New Member
Hearth Supporter
Sep 14, 2006
18
Champlain N.Y.
I have a new quadrafire 5100 insert I installed this month. I was wondering if you guys could answer this question for me. Will my stove burn the wood in the firebox faster with the fan on high compared to it on low. I seem to think the only way for the wood to burn up faster is if the draft is open to a higher btu rating but just wanted to make sure. If its not going to burn up my wood faster I will keep it on high on the cooler days. Any insight on this would be greatly appreciated.
 
I believe the main thing that having your fan on does is lower the temperature of the firebox by drawing heat away from it. That's why my Regency I2400 says the fan should be turned off for 30 minutes after loading fresh wood -- they want the firebox to get hot quickly so it can sustain secondary combustion (noncat stove).

With my stove, if I have a large load of wood and the air control is wide open and the fan is off, the stove can actually get too hot so that it starts to glow red. So one thing the fan can do for you is let you burn with more air for a higher heat output without overheating the stove. That's useful when you really want to get the max BTUs you can. The fan can serve to draw heat away from the stove so it doesn't overheat even when it's producing more heat than it could safely handle without the fan on.
 
There's no direct connection between the air intake and the room fan, so no more wood will burned with it on high than low. However, if you are burning a small fire then the high setting may cool the stove too much to put out heat. It also may cool down the exhaust gases leading to creosote build up or poor draft. When it's cold outside and the snow's flying, and a nice big fire is burning in the stove, it's fine to run it on high. The stove's manual gives more details on this. A stove thermometer can also help as a guide to stove temps.

Heydan, it sounds like you need a stove thermometer. Most stoves will overfire with a full load of wood and the air control left wide open. That is generally not advised unless the stove has a thermostatic air control. If the stove is glowing red, it's overfiring and too hot. This can damage the stove and void the warranty. Turn down the air control after the wood has started to char.
 
Yes, I agree -- red hot is too hot. I only saw that happen once and I don't intend to repeat it.

I do have a stove thermometer but my insert doesn't have any really good place to put it. I've got it just above the door right now which is the best I can do but that's still the outer wall of a double walled stove. It gives me a relative indication of what's going on inside the stove but that's all.

I wish someone would make a thermometer that could withstand the temperatures inside the stove so I could put it inside my insert and view it through the window.
 
Can you place the thermometer on an area that glowed red? That would be the hottest spot. Alternatively there are digital infrared thermometers that one just points at a surface and reads from the comfort of the armchair. They can be pointed right at the glass and will give you a good sense of what's hapening in the firebox. Harbor Freight and Sears have them.

https://www.hearth.com/talk/threads/3522/
 
I run my fan on almost low all the time. It seems to come out hotter and heat the house much faster than when it's on high. I think a high setting blows too hard and seems to cool the air a bit too much as it comes over the top of my stove.

I'm sure it heats ok on high, but it seems to be much hotter air blowing when on low.

I have my temp. gauge located on upper left corner on the front of my stove (see link). There is a spot here that is just regular thickness of steel and it seems to read fine.

Also, I got a laser temp. gauge to back up the other, it is right on the same temps. and soooo much fun to use all around my stove, walls, etc.

My stove, notice upper left corner........
(broken link removed to http://www.warmingtrendsstoves.com/mission_ws.html)


Robbie
 
Yes, this varies with stove blower design. Squirrel cage fans tend to move more air and can be noisier. Regencies (and Avalons I think?) are squirrel cage, the Quad 5000i uses a muffin fan.
 
Mine uses a squirrel cage type, very low noise and really blows.

At this time, my stove is heating my entire 1850 sq. ft. house with an upstairs, and keeping it always around 78 when it's in the mid to upper 30s outside.

I'm learning a few tricks this year too, I've been loading less, and burning hotter, using the fan all night to heat.

Last year I loaded as full as I could, and dampered, using no fan. It heated ok during the night but my gas heat always kicked on around dawn. It was set on 74 last year, this year we've got it set on 68.

Loading less wood means it can only get so hot, and last so long, this takes a little practice but I have figured out how to get a good steady burn with damper opened slightly, and using blower seems to put heat in the house at a safe steady rate all night, by morning there is still hot coals and blower is still blowing medium hot air, which is much better than last years operation.

It is rather deceptive in that the when you have a good fire, and it is flaming really well, and your blower is on, it does seem as though your fan could be feeding the flame.

I've wondered when a company is going to come up with a method to force air on a wood stove from outside (with a fan) in order to get temps. up or just to assist in getting the fire honking.........guess this could be rather dangerous because it could over fire, but it could also be included as an add on type accessory or optional.......call it the "Turbo Air Assist"......... :cheese:

I think pellet stoves have this now.

Robbie
 
Our woodfurnace uses our gas furnace's blower to distribute the heat. Alot of airflow goes through the woodfurnace into home. I have it set where it kicks off at around 85 degrees. You would think that slow hot heat would be better, But I have found that the cooler air that comes out of our registers runs almost all of the time. This helps to evenly distribute the heat throughout the home. We have not a single hot or cold spot in our house. The furnace blower is always running on high. I find it more efficient.
 
BeGreen said:
Can you place the thermometer on an area that glowed red? That would be the hottest spot. Alternatively there are digital infrared thermometers that one just points at a surface and reads from the comfort of the armchair. They can be pointed right at the glass and will give you a good sense of what's hapening in the firebox. Harbor Freight and Sears have them.

https://www.hearth.com/talk/threads/3522/

Thanks, I just put in an order for a laser thermometer from Harbor Freight. The part of my stove that glowed red is not accessible to a physical thermometer. I could only see it through the air vent. But I might just be able to shine a laser thermometer in there.
 
I would have to put my vote in and say you might actually burn less wood - assuming all else is equal. The reasoning is twofold:

1) The fan is cooling the firebox which means cooler flue gasses, less draft, less intense fire and lower wood consumption rate. This is where the "all else being equal" comes in because this assumes that you don't open the draft air more to compensate.

2) Since the fan is pulling more heat out of the stove, you are getting more heat into the room which means the overall efficiency is better so you won't need to fire the stove as much for the same heat, which will result in lower consumption.


Actually, while typing, I thought of one instance that might raise wood consumption - if you cool the stove enough to lose secondary combustion, that might be a less efficient state of operation requiring more wood.

Corey
 
I've recently got a quadrafire 4100i and have been playing around with different settings. I find that if the stove is hot enough for the snap disc to decide that the fan should be on its hot enough that the fan isn't going to have any noticeable cooling effect on the fire even at its highest setting. I've taken to leaving the fan on high all the time in the auto setting (a little lower if I'm watching television and want it a little quieter). When I've got the fan on too low the only place it tends to feel really warm is directly in front of the fireplace.
 
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