pellet insert in fireplace -- how much heat? (PIC) (floor, my fireplace, furnaces)

[karen_in_nh_2012]

I am trying to think of ways to reduce the heating costs of my house. Most of the house is heated with oil via forced hot air through an extensive duct system. I am considering a pellet insert for my fireplace. At my last house my furnace was a pellet furnace so I am pretty familiar with the technology, and generally like it. (And in 5-6 years, pellet prices have gone up but they're still way cheaper than oil on a BTU basis.)

Below is the layout of most of the first floor of my house (each square equals 1 square foot). The pellet insert would be in the fireplace in the living room, which is the room on the left. The kinds that I am looking at say that they heat up to 2,200 square feet, but I don't ever really trust those numbers, since your house would have to be ideal (e.g., open-plan ranch, which is ironically what my last house was!) in order for the heat to really get everywhere in the house.




I would have a little fan in the doorway leading into the living room; it would distribute some of the hot air from the pellet insert into the hallway and across the foyer into the dining room. (I bought a little fan at amazon and it has worked great for moving hot air from a hall vent into a bedroom that doesn't have its own vent -- I would buy a few more of those little fans, as they work surprisingly well.)

My biggest question is, how well do you think the other first-floor rooms would be heated? I don't expect to be able to turn the oil furnace off -- I am just hoping it wouldn't be needed nearly as much when I am at home and the pellet insert is on.

Note, the far-right room on the drawing is my TV room. Do you think any of the heat from the pellet insert could make its way back there, or is it just too far away? (It actually has its own source of heat in addition to the forced-hot-air, so I could always turn that on in a pinch, although I haven't used it at all this winter.)

Also, I would be adding a ceiling fan at the top of the stairs to circulate some hot air to the bedrooms up there. Given that I'm not in them too often during the day, I think that would keep them warm enough. Any thoughts?

Thanks in advance!

[thecoalman]

Originally Posted by karen_in_nh_2012

The kinds that I am looking at say that they heat up to 2,200 square feet, but I don't ever really trust those numbers, since your house would have to be ideal (e.g., open-plan ranch, which is ironically what my last house was!) in order for the heat to really get everywhere in the house.

......and you need to live in Florida and have super insulation. How many BTU's is it?

If it were me I'd be looking at something I can tie into the existing duct work, I don't know if they have anything like that for pellets. I'm aware of one fuel you can do that with.

[RyanR]

What's the BTU's on that insert? I have a 75,000 BTU wood insert and for temps above about 20-25 degrees it heats our whole house (approx. 3400 sq/ft).

For air movement, we run our furnace fan 24/7. It has a low-speed setting that we run year around to equalize temps and humidity throughout the house.

[thecoalman]

Originally Posted by RyanR

What's the BTU's on that insert? I have a 75,000 BTU wood insert and for temps above about 20-25 degrees it heats our whole house (approx. 3400 sq/ft).

Mild climate? 6 inch walls and insulated well?

[karen_in_nh_2012]

Originally Posted by RyanR

What's the BTU's on that insert? I have a 75,000 BTU wood insert and for temps above about 20-25 degrees it heats our whole house (approx. 3400 sq/ft).

For air movement, we run our furnace fan 24/7. It has a low-speed setting that we run year around to equalize temps and humidity throughout the house.

Wow, this surprises me a lot although of course that is major BTUs! Where do you live? Where is the wood insert in relation to the other rooms of your house? EG my last house was basically a large rectangle with an open floor plan for the main rooms -- I can definitely see an insert heating a house like that very well. Alas, my current house isn't really like that, which is why I included the floor plan. Is your house anything like my current house?

I'm in New Hampshire and we do have some days/nights where the temps are in the single digits or even below -- e.g. in the next week overnight temps are expected to be 13, 17, -1, -3, 5, 9, and 2 (eeeeek!).

Originally Posted by thecoalman

How many BTU's is it?

If it were me I'd be looking at something I can tie into the existing duct work, I don't know if they have anything like that for pellets. I'm aware of one fuel you can do that with.

I have read good things about coal (and not only from you ), but there are few dealers in my area and it's almost as expensive as oil on a BTU basis (or at least it was when I checked a few months ago).

To tie it into my existing ductwork would require, I think, a second furnace or stove in the basement. (EG at my old house, I started off heating with oil and then switched to a pellet furnace after living in the house a few years. So that house has 2 furnaces both tied into the same duct work.)

One insert I'm looking at is the Harman Accentra -- 42,000 BTUs, listed as heating from 800 to 2,200 square feet (although again, I don't trust those square foot figures). The other is the Harman P35i insert, 35,000 BTUs, listed as heating from 800 to 2,100 square feet.

I am curious -- I have read on other forums about leaving the furnace's fan on to circulate air, but I can't figure out how that would work -- does this mean the duct work is circulating heat from an insert? There ARE 2 cold air returns in the living room -- one is to the left of the fireplace (looking AT the fireplace) and the other is on the shared wall with the hall, basically directly across from the fireplace although about 13'6 feet away (the width of the room). If I could figure out how to turn the oil furnace's fan on (no heat, just the fan), does this mean the heat from the pellet insert in the fireplace would be able to circulate via the duct work? RyanR, is that what you meant when you said that for air movement, you leave your furnace's fan on?

Thanks for the replies -- I'll rep you both (and anyone else who can help!).

[thecoalman]

Originally Posted by karen_in_nh_2012

I have read good things about coal (and not only from you ), but there are few dealers in my area and it's almost as expensive as oil on a BTU basis (or at least it was when I checked a few months ago).

That's not possible or you're checking prices with someone who thinks they are selling gold. What kind of prices were you getting?

Cost per million BTU:

Coal @$400/ton 80% eff. = $20.83
Coal @$8/40 pound bag 80% eff. = $20.83

Wood Pellets @$2.25/40 pound bag 70% eff. = $19.48

Oil @$3.50/gallon 80% efficiency = $31.55

$400 per ton is a very high price, I'm only paying $180 per ton and that's delivered in bulk into basement. You're going to pay more than that but it should be in the $300 to $350 range.

Note there is efficiencies assigned here, coal stoves are typically very high. There is new model on the market now tested in the low 90's. Wood pellets can never achieve that.

To tie it into my existing ductwork would require, I think, a second furnace or stove in the basement.

Yes and the major hurdle is if you have flue for it. If you don't have a flue what you can do is power vent but power vent the oil, check your codes. In a system li8ke that the coal/pellets can be your primary heat and you're only going to to use the oil when necessary. Keeping the oil also provides the benefit of being able to leave for a vacation in the winter.

One insert I'm looking at is the Harman Accentra -- 42,000 BTUs, listed as heating from 800 to 2,200 square feet (although again, I don't trust those square foot figures). The other is the Harman P35i insert, 35,000 BTUs, listed as heating from 800 to 2,100 square feet.

Good to see you're not buying junk. That's plenty and I probably would opt for the smaller one if there is significant difference in the costs unless you can figure out how to move the heat. I would consider the 800 sq. ft. figure as being more accurate measurement but if you have a new house with 6 inch walls and insulated well.... There is a lot of variables here and you need to do a heat loss calculation which will tell you how many BTU's you need.

I am curious -- I have read on other forums about leaving the furnace's fan on to circulate air, but I can't figure out how that would work -- does this mean the duct work is circulating heat from an insert?

You're moving air just like you would with a room fan, I'm not so sure it would make sense having one right next to the insert though.

If you do this right you don't even need a fan but you need to terminate the cold air return near the heat. For example let's say you have simple setup where you duct the heat from the basement right into the upstairs. At the further end of the house you'd place a cold air return and terminate that near the stove at ground level. As the heat pushes up into the ducts the colder air at the farther part of the house will get pulled into the return. That's how they circulated heat years ago.

[karen_in_nh_2012]

When I checked coal prices here a few months ago (I called at least half a dozen places and only one sold it) it was $381 per ton IIRC. Oil at that time was $3.20/gallon (it's more now). Unfortunately where I live there's just not a whole lot of competition around coal so the price is high.

Originally Posted by thecoalman

You're moving air just like you would with a room fan, I'm not so sure it would make sense having one right next to the insert though.

If you do this right you don't even need a fan but you need to terminate the cold air return near the heat. For example let's say you have simple setup where you duct the heat from the basement right into the upstairs. At the further end of the house you'd place a cold air return and terminate that near the stove at ground level. As the heat pushes up into the ducts the colder air at the farther part of the house will get pulled into the return. That's how they circulated heat years ago.

Sorry, I'm not understanding that -- I was asking about using my oil furnace's fan-only setting (assuming it has one) to circulate the heat from the pellet insert in the living room's fireplace to the rest of the house. I have read in other forums about people doing that, but there are never any details and I would like to understand exactly how it works.

I think what you wrote above is more about a second furnace? Do you know anything about using an existing furnace's fan-only setting to circulate heat with an insert? (The alternative is to use those little doorway fans ... as I wrote in the OP, I have one of those now to move heat from a hall into a bedroom that doesn't have its own vent.)

[thecoalman]

Originally Posted by karen_in_nh_2012

When I checked coal prices here a few months ago (I called at least half a dozen places and only one sold it) it was $381 per ton IIRC. Oil at that time was $3.20/gallon (it's more now). Unfortunately where I live there's just not a whole lot of competition around coal so the price is high.

That's a bit high but not unheard of especially if the quote was for bags, the trouble with coal once you get out of the Northeastern Pennsylvania is bulk delivery is not common and the shipping plays a huge factor. I any event:


Coal @$381/ton 80% eff. = $19.84


Oil @$3.20/gallon 80% efficiency = $28.84

Sorry, I'm not understanding that -- I was asking about using my oil furnace's fan-only setting (assuming it has one) to circulate the heat from the pellet insert in the living room's fireplace to the rest of the house. I have read in other forums about people doing that, but there are never any details and I would like to understand exactly how it works.

When you turn on the fan its going to pull air towards the cold air return, suppose you have a heating vent in the room by the fireplace and the cold air return is in your TV room. You're going to circulate that colder air from TV room into the fireplace room which will force the warmer towards the TV room, you're just creating a loop of circulating air. How effective that will be depends on how your duct work is setup. Also bear in mind now you have a fan running.

This can be done naturally with existing system but it has to be set up to do it that way.

This diagram is not the ideal way to do this but it will give you an idea:

[thecoalman]

Wood Pellets @$2.25/40 pound bag 70% eff. = $19.48

From my previous post this should have read:

Wood Pellets @$225/ton 70% eff. = $19.48

[HWTechGuy]

They do make pellet stoves that connect to your existing ductwork. Some are actually referred to as pellet furnaces.

I had a pellet fireplace insert installed at my home in PA. I brought it with me to FL and am going to get a fireplace built for it. We do get some very cold nights here (high 20's) and plenty of cold/cool (30's/40's) nights and it'll be perfect to take the chill off.

I have the Quadrafire Mt. Vernon AE which is rated for up to 3000 sqft, but I had a really hard time getting the warm air moved around my 2800 sqft home. But, I was able to do it for the most part and keep the furnaces off most of the winter.

Fans can help, and it's actually best to blow cold air towards the stove, and it will in turn be replaced by warm air through natural convection. I had a few of those small Vornado fans on the floor to blow the cold air towards the living room where the stove is and another one in that room blowing right at the stove. In my case, running the air handlers for my furnaces did next to nothing in terms of moving the warm air around the house.