Insert Fan...How Necessary Are They?

[jscs.moore]

Hey guys,
I'm my third burning season with my Hampton HI300. My set up is 2000sq ft Center Hall Colonial with an open floor plan. I have an insulated liner with a 28ft exterior chimney and had the dealer install a block off plate last year. I've noticed this year that even in colder temps (28 last night) that with the block plate we can get cooked out of the family room if I'm burning a full load of seasoned oak.

It got to the point last night that I shut the insert fan off after the load had burned down about half way because it was just too uncomfortable with the heat output while watching TV. I thought that without running the insert fan (usually on low most of the time) the room temp would decrease quickly, but I was wrong. The magnetic thermometer starting climbing and about 20 to 30 minutes later was at the upper end of cruising temp (550 degrees) and the room was still very, very warm? The rest of the house and upstairs very toasty.

So I'm just curious if any insert owners operate without using the internal fans much? I have always used the internal fan because I always read that insert are very reliant upon the fans to move the heat throughout the house? But it was 28 degrees last night and with just a half load left in the firebox I was able to get real heat radiating off the HI300 and moving thru the house without using the fan? Makes me wonder how it would operate if I packed the firebox full of dry wood and didn't use the fan at all? Would I be able to keep heat the whole house as quickly and comfortably? I guess I would also be concerned about overfiring without using the internal fan?

 

[begreen]

Most insert owners use their fans at low speed during the time the fire is burning. It does keep the firebox and jacket cooler. The house sounds pretty well insulated. The issue you are experiencing is common for center colonials. It's more a question of heat circulation. How are you assisting heat circulation throughout the house? Is there a fan blowing from an adjacent room (at floor level) into the family room?

 

[RobbieB]

I always use the fan set to a lower speed, it doesn't make much noise. I don't use a lot of wood though, I make small hot fires and add as needed. If you don't turn on the fan it's going to get really hot with all the heat soak and no air over and I don't think that will be good for the motor or the speed control electronics.

 

[jscs.moore]

Most insert owners use their fans at low speed during the time the fire is burning. It does keep the firebox and jacket cooler. The house sounds pretty well insulated. The issue you are experiencing is common for center colonials. It's more a question of heat circulation. How are you assisting heat circulation throughout the house? Is there a fan blowing from an adjacent room (at floor level) into the family room?

The insert is in the family room that has a 9ft ceiling. Right in the middle of the family room ceiling and directly in front of the insert we have a ceiling fan which is always circulating at low speed. I guess this moves the heat pretty well on its own without the insert fan? Also, the floor plan is very open so the heat just moves throughout the house and upstairs very easily.
I'm somewhat encouraged by this finding because I have been concerned that in a power outage I would not be able to keep the house warm...I'm now thinking I probably can, just not as warm as having the fans moving the air?

 

[illini81]

It's more a question of heat circulation. How are you assisting heat circulation throughout the house? Is there a fan blowing from an adjacent room (at floor level) into the family room?

+1

I also am heating a colonial of similar size and with an insert. I almost always have my fan as low as it will go. I am not sure if I have a center hall colonial, but my first floor is split in half with a single doorway that connects the two halves. The stairs are on the side of the house that the stove is not on. As long as I have a box fan at the entrance of this doorway pointing into the stove room, the stove room stays pretty consistently 70-74 degrees, while the rest of the house (including upstairs) is around 64-70.

 

[saewoody]

My fan is always running. I did an experiment the other night and turned the fan to low, rather than high (where it usually is). Based on what I experienced, my house seems to be better off with the fan on high.

What does the block off plate do? I’m guessing I don’t have one. Sounds like maybe it keeps the heat from the back of the stove from going up the chimney.


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[begreen]

What does the block off plate do? I’m guessing I don’t have one. Sounds like maybe it keeps the heat from the back of the stove from going up the chimney.

Yes, an insulated block-off plate keeps the heat around the the insert instead of a lot of it going to heat up the mass of masonry in the chimney. If the chimney is exterior the heat loss can be high. If there is room, a bit of proper insulation behind the insert can also help.
https://www.hearth.com/talk/wiki/why-damper-seal-is-needed/

 

[saewoody]

Yes, an insulated block-off plate keeps the heat around the the insert instead of a lot of it going to heat up the mass of masonry in the chimney. If the chimney is exterior the heat loss can be high. If there is room, a bit of proper insulation behind the insert can also help.
https://www.hearth.com/talk/wiki/why-damper-seal-is-needed/

Thanks!


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[yooper08]

I run my fan on low nearly all the time, probably the first 80% or so of the load. My other fan blowing cold air into the room is also always on except for when I reload.

 

[velvetfoot]

The magnetic thermometer starting climbing and about 20 to 30 minutes later was at the upper end of cruising temp (550 degrees)

Where is your magnetic thermometer located? I haven't measured with the IR gun for a while.

My unit burns really hot for a good while on a new load even with the lever all the way to the right. I've taken to running the fan on high until the flames subside. I think it's the very tall chimney. I would really like to cut down on the minimum air, but don't think there's a way.

Anyway, the only way I can see to use this unit in a power outage would be very small loads.

 

[bholler]

Where is your magnetic thermometer located? I haven't measured with the IR gun for a while.

My unit burns really hot for a good while on a new load even with the lever all the way to the right. I've taken to running the fan on high until the flames subside. I think it's the very tall chimney. I would really like to cut down on the minimum air, but don't think there's a way.

Anyway, the only way I can see to use this unit in a power outage would be very small loads.

There is absolutly no reason you would have to run any differently in a power outage.

 

[velvetfoot]

There is absolutly no reason you would have to run any differently in a power outage.

How about if it's a high draft installation and the temperatures skyrocket with no other way to remove heat from the insert but radiation and natural convection?

 

[jatoxico]

My flush insert needs the fans to get any heat out of it. Prob won't over-fire w/o power if I run a normal load but it will run hotter for sure.

 

[bholler]

How about if it's a high draft installation and the temperatures skyrocket with no other way to remove heat from the insert but radiation and natural convection?

Then you need to fix your install so it is controllable by restricting the intake or we have even fabricated pipe dampers for inserts with a knob through the faceplate or the face of the fireplace. You should never be relying on the blower to control your stove.

 

[bholler]

My flush insert needs the fans to get any heat out of it. Prob won't over-fire w/o power if I run a normal load but it will run hotter for sure.

Yes some inserts need fans to put out decent heat but they should be able to run safely without it.

 

[velvetfoot]

Let me put it this way, I've never tried. Maybe it'd be fine. I wish the intake was more controllable instead of the one-size-fits-all epa thing.

 

[bholler]

Let me put it this way, I've never tried. Maybe it'd be fine. I wish the intake was more controllable instead of the one-size-fits-all epa thing.

And i am telling you you should try. And if it is uncontrollable address it now not when you have just loaded the stove and the power goes out

 

[RobbieB]

I bought a 300 watt sine inverter and a 35 AH battery. Should be good for 5 hours of no power.

 

[twd000]

I run my Blaze King insert without the fan about 90% of the time. I typically set the thermostat at 30-40% of max. That keeps the main floor at 70-74. Upper floor would be at 64 or so; we let the propane furnace boost to 68 up there to minimize complaints from the wife and kids.

 

[jatoxico]

Yes some inserts need fans to put out decent heat but they should be able to run safely without it.

Yes but to @velvetfoot 's point the extra heat retention does make it more likely to reach too high a temp. I would be more careful if I had to run w/o fans too.

As far as inserts that protrude from the fireplace, these are are far less dependent on the fans. I used to run an old Elmira insert and the fans could be run on low or not at all and it still heated pretty well.

 

[velvetfoot]

I typically set the thermostat at 30-40% of max.

True that cat inserts are more controllable compared to the tube variety, say, in the presence of higher than normal draft?

 

[jscs.moore]

There is absolutly no reason you would have to run any differently in a power outage.

Thanks bholler...I was hoping someone would say that! I've burning three seasons now and still have not had a power outage to deal with. But in anticipation of one...I was hoping I could run the insert as I normally would in order to try and keep the house relatively warm and not have the pipes freezing, etc. I did purchase a couple of eco-fans (canfrano air-max) last year that I've played with in order to move the heat around during a power outage. I know many on this site discount them, but in my testing they do seem to move the warm air fairly well...not as well as the insert fan, but I think they will help.

 

[twd000]

True that cat inserts are more controllable compared to the tube variety, say, in the presence of higher than normal draft?

I suspect it is the thermostat that makes it more controllable, as opposed to the cat vs. tube difference.

The thermostat is attempting to maintain the firebox temperature at a fixed value, so if the draft is stronger, it will close the air flapper slightly to compensate

 

[freddy]

My insert does not have a fan and it throws a ton of heat. Previous inserts had fans and needed it. Depends on the stove and design apparently...?

 

[saewoody]

Well I just had to deal with a flue collar gasket replacement this weekend. And I figured since I had the stove pulled out it would be a good time to clean out the blower. I’m so glad I did. The stove is pushing a lot more hot air out into the room. The squirrel cages on my blower were so caked I can’t believe they were still moving any air. It looked like they had been wrapped in a wool sweater! It’s like I’m running a new stove. I’ll have to make this a part of my yearly maintenance. I apologize for not taking pics. I definitely should have.


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