Question on wood-burning insert or stove for NH home

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adatel

New Member
Feb 25, 2019
18
New Hampshire
Hi,

I am a new poster but I have been lurking and read a lot of posts here over the past couple months… you folks have a wealth of experience and perspectives and I’ve learned a lot (and still have a lot to learn)! I am hoping you might be able to provide me with some advice.

I live in Southern New Hampshire in a big (3500 sq ft), house built in 2002. Propane bills are very high and I want to bring them down! The house is very well insulated (2x6 construction with gaps filled plus 1-2” insulation board applied on top of that) but the living space has lots of big, beautiful windows. They are well sealed and double insulated but of course their R rating is intrinsically low!

I have a really big masonry fireplace in the middle of the great room which is about 1600 sq ft including living, dining, kitchen with ceilings of 9 to 12 feet (and lots of glass). When I light a fire, it is beautiful and it does a great job of sucking warm air out of the house and out the chimney!

I have 10 acres of forest and chainsaws/axes and a drying shed, so I am all-in to reduce my propane costs with burning wood in an ecologically reasonable way.

I do care about the aesthetics of my solution, though, which, together with the size of my firebox leads to some challenges….

My first thought was a wood burning insert with a blower, but two issues with that: First, the fireplace opening is so big (46.5” wide and 41.5” tall) that I couldn’t find any that even approximated those dimensions; even if I were to put one in and then put a big black steel surround panel, the insert and its glass door are going to look puny and silly compared to the overall fireplace and beautiful granite surround. Second, I really want something that can put out a lot of heat and it seems that inserts don't have large fireboxes and they are not as good at creating heat as woodstoves.

So, based on some posts here, I started thinking about a stove sitting as far as possible back into the brick firebox and extending onto the hearth – a big one like the Lopi Liberty, for example – with a blower and the chimney pipe running straight up through the open/removed damper (surrounded by a sealed plate etc) and maybe a new metal liner up the chimney (bedroom floor above plus high attic under my steeply pitched roof).

However, I don’t want to/can’t extend the beautiful granite hearth, or mess with the beautiful granite surround.

My questions are these:

1. Am I right that there are no big/ tall inserts that would look good in such a tall and wide fireplace opening, and that for maximizing heat I am better off with a stove?

2. If I have a stove partially sitting in my original brick firebox what does that means about rear and side clearances – since the masonry is non-combustible, can I assume I can ignore the clearances there? And what about the front clearance – since the granite hearth is a foot off the floor, do I need the full clearance for the stove in front or does the dropoff reduce or eliminate the front clearance requirement? Or, could I place a hearth mat in front of the (granite) hearth on top of the hardwood floor to get around that?

3. Any recommendations for specific "large firebox" woodstoves that are really solid and well built -- I am willing to pay a premium for something that won't give me trouble?

4. Any other ideas?

Thanks to all the posts, I understand I need to be burning well-seasoned wood and I need to be careful to make sure I clean out the creosote on at least an annual basis to reduce the likelihood of a flue fire.

Some more measurements/specs:

- Firebox is 47.75” wide in front and 23.75” wide in rear; 22.75” deep
- Fireplace opening is 46.5” wide and 41.5” tall
- Hearth is granite set on masonry/poured concrete 20” deep in front of fireplace and 12” above the hardwood floor in front of it
- Fireplace surround is 1.5” granite set on mix of masonry and cementboard
- Firebox has ashdrop in floor down to basement cleanout
- Firebox has external air input in right rear that is connected to a metal pipe going out to side of house to screened vent (about 4-5” diameter – sort of like a dryer vent)
- Current fireplace draws well

Thanks so much for any help!
Anthony
 

begreen

Mooderator
Staff member
Nov 18, 2005
90,694
South Puget Sound, WA
You're on the right path. There's room for a large freestanding stove. It will still need at least ember protection on the floor to protect at least 16" from the glass. This should be semi-permanent at least. A fireplace rug is not the best, but a thin flat hearth pad would work. It should be anchored with at least a couple screws but could be removed in summer. Or perhaps just a flush, copper (or other metal) extension at floor level? Look at stoves in the ~3.0 cu ft range. There are several that would work. Consider how it loads (E/W only or E/W and N/S) and get it with a blower. Note that a blower on back may extend it further out into the room.

How tall is the chimney? It will need a full liner that matches the stove requirements. And the install will need an insulated block-off plate, preferably at the lintel level, to keep heat in the room.
 
Last edited:

peakbagger

Minister of Fire
Jul 11, 2008
6,635
Northern NH
IMHO A house that size deserves a boiler with storage as you need to get the heat to where you need it and that's at the base of the windows and outer walls. Have someone do a Manual J heat loss Calculation and see where the heat loss is and what you may need to combat it.

The problem with those big windows is they have significant radiant loss where the cold goes right through the glass and cools down whatever surface is in sight. Double insulated blinds with side seals make a big difference but they are not cheap. In order to combat that radiant loss you need to keep the space temp much higher. An insert no matter how big it is just a space heater and despite fans and blowers is not that great at moving heat around the house. You are far better with free standing wood stove even though its still just a space heater and unless you cut a lot of vents and install fans the rest of the house will feel cold.

The big caveat is unless you have a proven verified source of wood that has been properly stored and seasoned for two full years you are up for nothing but frustration if you install a stove this summer and try to burn this fall. The likelihood of finding 2 year seasoned hardwood anywhere in NH is slim to none unless you pay a major premium. Not sure of the rule of thumb of propane to wood but the rule of thumb for heating oil is about 100 gallons of oil for one cord. I would guess its less for propane. So figure out how many gallons of propane you bought for heating shoot for around 85 gallons per cord and it will get you in the ball park. Now double this amount and start cutting an splitting. My guess is 5 cords a season so you need 10 cords sitting for 2 years and then you ready to burn wood. Unlike the older non EPA stoves, newer EPA stoves just don't burn that well.

If you ignore the seasoned wood issue any new stove is going to give you trouble no matter what you pay. One of the best brands out there for freestanding is Woodstock and the factory is in the upper valley (west Lebanon).
 

adatel

New Member
Feb 25, 2019
18
New Hampshire
You're on the right path. There's room for a large freestanding stove. It will still need at least ember protection on the floor to protect at least 16" from the glass. This should be semi-permanent at least. A fireplace rug is not the best, but a thin flat hearth pad would work. It should be anchored with at least a couple screws but could be removed in summer. Or perhaps just a flush, copper (or other metal) extension at floor level? Look at stoves in the ~3.0 cu ft range. There are several that would work. Consider how it loads (E/W only or E/W and N/S) and get it with a blower. Note that a blower on back may extend it further out into the room.

How tall is the chimney? It will need a full liner that matches the stove requirements. And the install will need an insulated block-off plate, preferably at the lintel level, to keep heat in the room.
Thank you for the advice about the ember protection; makes perfect sense and good useful ideas. Also about the potential size of the blower.
The current masonry chimney from the damper up to the exit above the house is about 30 feet.
 

adatel

New Member
Feb 25, 2019
18
New Hampshire
IMHO A house that size deserves a boiler with storage as you need to get the heat to where you need it and that's at the base of the windows and outer walls. Have someone do a Manual J heat loss Calculation and see where the heat loss is and what you may need to combat it.

The problem with those big windows is they have significant radiant loss where the cold goes right through the glass and cools down whatever surface is in sight. Double insulated blinds with side seals make a big difference but they are not cheap. In order to combat that radiant loss you need to keep the space temp much higher. An insert no matter how big it is just a space heater and despite fans and blowers is not that great at moving heat around the house. You are far better with free standing wood stove even though its still just a space heater and unless you cut a lot of vents and install fans the rest of the house will feel cold.

The big caveat is unless you have a proven verified source of wood that has been properly stored and seasoned for two full years you are up for nothing but frustration if you install a stove this summer and try to burn this fall. The likelihood of finding 2 year seasoned hardwood anywhere in NH is slim to none unless you pay a major premium. Not sure of the rule of thumb of propane to wood but the rule of thumb for heating oil is about 100 gallons of oil for one cord. I would guess its less for propane. So figure out how many gallons of propane you bought for heating shoot for around 85 gallons per cord and it will get you in the ball park. Now double this amount and start cutting an splitting. My guess is 5 cords a season so you need 10 cords sitting for 2 years and then you ready to burn wood. Unlike the older non EPA stoves, newer EPA stoves just don't burn that well.

If you ignore the seasoned wood issue any new stove is going to give you trouble no matter what you pay. One of the best brands out there for freestanding is Woodstock and the factory is in the upper valley (west Lebanon).

Good points. I guess I am not sure I am all-in enough to do the whole house wood-burning furnace/boiler. That is a lot of wood and stoking! I was hoping to reduce propane consumption but assumed I couldn't eliminate it, at least not at this point.
Practically, the propane system is hot air (connected to same blower as the HVAC) and so I am stuck with hot air. Are there hot air wood burning furnaces (I wasn't aware)?
As for the quantity and quality of wood, understood. I started cutting, splitting, drying about 8 months ago, but I hear you about the need for dryness. Thanks for the emphasis.
And thanks a lot for the tip to Woodstock -- looks like they have some interesting products for me and they are relatively close. I didn't know about them before!
 

peakbagger

Minister of Fire
Jul 11, 2008
6,635
Northern NH
Well if you already have hot air you can go ground source geothermal and skip the wood and put in solar panels to run the geothermal. Of course with a house that size I expect your front yard will look like porcupine as at 250 feet per ton (12,000) btus/hr you would need several bore holes. I think the state offers incentives but its not cheap.

Hot air wood furnaces do not really fit well as there is no storage capacity so you need to try to match the load to demand and that means part load operation which can lead to low efficiency plus creosote. On the other hand if the ducts are big enough you can just put in a couple of properly sized hot water coils on the main runs and use a hot water boiler with storage to feed the coils. The reason for storage is you run the boiler flat out for a few hours day to heat the storage up, then you run off storage until its cooled down. Running a boiler flat out is the most efficient way to burn, the emissions are lower and creosote is minimal if at all with seasoned wood.

The Woodstock Ideal Steel is a major award winner and super clean and efficient. I have not heard any bad reviews for them and they are local. Be careful if you go to visit them, odds are you will leave with one or at least a deposit on one.

The other folks nearby are these folks in Lyme NH https://www.woodboilers.com/. They post on this forum on occasion.

I am up in northern NH and haven't bought oil for five years. I heat with wood in the winter and use a minisplit for shoulder seasons that I run off of excess solar generation with net metering. With some work I could probably cut my wood use down but I cant justify it financially.
 

begreen

Mooderator
Staff member
Nov 18, 2005
90,694
South Puget Sound, WA
Woodstock makes good stoves, but there is the caveat that none have a blower option. In this circumstance a blower will make a significant difference in convecting the heat. This can help deliver more heat more evenly in a big space, especially when used in conjunction with a ceiling fan.
 

kennyp2339

Minister of Fire
Feb 16, 2014
6,129
07462

peakbagger

Minister of Fire
Jul 11, 2008
6,635
Northern NH
I was envisioning that the stove would be installed outside the fireplace opening. IMO in that case direct line of site radiant heat would trump convection blowers. In large room there is not normally a lot of need for convection blowers as natural convection starts pretty quick with stove sitting in it. a personal bias is I hate listening to fans.
 

adatel

New Member
Feb 25, 2019
18
New Hampshire
I was envisioning that the stove would be installed outside the fireplace opening. IMO in that case direct line of site radiant heat would trump convection blowers. In large room there is not normally a lot of need for convection blowers as natural convection starts pretty quick with stove sitting in it. a personal bias is I hate listening to fans.

Wow! Thank you so much for these interesting and helpful replies. It has sent me reading more about BK stoves on the site, Woodstocks, and lots of other threads, etc.

I had been thinking I would tuck the stove into the fireplace as much as I could (since I am constrained on the current depth of the hearth. (Although for heat, bringing it out further is better – I get that—and could at least partially mitigate lack of a blower which is a good point.)

But when I look at the BKs versus the Woodstocks the larger BKs (I like the automatic burn control and even longer burn times and the blower options) seem to only have vent exits from the top and then minimum two foot vertical before turning horizontal into the fireplace.

So, even with my tall fireplace opening, I won’t have enough space for that (and I don’t want to send the pipe in higher on my wall above the fireplace surround and cut into the masonry flue – it would look awkward in my space). Whereas the Woodstock has the rear vent option so I think I could send it horizontal into a cleanout T connection and then a stainless pipe snaked up through the masonry chimney. So, I think I need that rear vent exit. Am I missing something here?

I just found this thread (there is so much content here!!) which talks about this specific constraint with BKs – since I have a very tall chimney (35 feet or so above the damper), maybe I can get away with a couple 45s to get into the chimney flue without the 2 feet “minimum”: https://www.hearth.com/talk/threads/blaze-king-install-question-vertical-pipe-rule.119476/

How important is the cleanout T-junction which both BK and Woodstock “recommend” in their installs versus sending it up directly? To clean, can I or a sweep just open up the vent connector to clean, or would I make a big mistake by not putting in a T cleanout junction?

(As for the geothermal heat pump – super cool technology!! I didn’t even know about it before but of course the physics make perfect sense. I like the renewable profile a lot, but looks like in practice would be a very long payback period – back of the envelope looks like around $40K for geo alone plus the solar install for the electricity (another 30 or so). I think easily 20 year payback when you add in maintenance costs etc and then I wonder about system life. Maybe I am off but it just doesn’t seem economic for individual houses at the current pricing?)
 

begreen

Mooderator
Staff member
Nov 18, 2005
90,694
South Puget Sound, WA
Why not vent straight up with the stove partially in the fireplace? The Liberty is also top vent only. By the first posting mentioning the Liberty as an option it sounds like there is enough room to vent vertically.
 

adatel

New Member
Feb 25, 2019
18
New Hampshire
Why not vent straight up with the stove partially in the fireplace? The Liberty is also top vent only. By the first posting mentioning the Liberty as an option it sounds like there is enough room to vent vertically.
The installation instructions on many of the stoves seem to recommend that you create a T-junction with a cleanout, so that was indeed my question: is it ok to just go (more or less) straight up from a top vent through the damper and they chimney and not leave a cleanout. Based on what you replied, I guess a lot of people do just that.... (thanks again for all the help from @begreen and @peakbagger !)
 

begreen

Mooderator
Staff member
Nov 18, 2005
90,694
South Puget Sound, WA
Yes, it's absolutely ok and done. Here is an Englander 30-NC installed this way. The best stoves for this kind of installation have an easily removable baffle or a clear-shot bypass to facilitate easy cleaning.

BrotherBart 30 first fire.jpg
 

BKVP

Minister of Fire
Welcome Adatel. Can you post a picture of your proposed install location. These guys here really respond to pictures and ALWAYS will catch little things that might be missed otherwise.
 
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weatherguy

Minister of Fire
Feb 20, 2009
5,832
Central Mass
Adatel, check my avatar, it's a picture of my stove in my fireplace, house is 2800sf so smaller than yours but I'm doing 75% of my heating with wood. Your fireplace us bigger so you have more options than I had choosing a stove.
 

Woody Stover

Minister of Fire
Dec 25, 2010
12,277
Southern IN
As for the quantity and quality of wood, understood. I started cutting, splitting, drying about 8 months ago, but I hear you about the need for dryness.
I'm scouring the woods now, but it's slow work grabbing a bunch of small dead trees with the bark fallen off. They are dry though. If you can hook up with a tree guy and get some free Red Maple by showing up when they are cutting, it will get pretty dry by fall if you get it split and stacked single-row in the wind, top-covered, right away. It doesn't burn as long as more dense woods, but you are in a jam. Pine dries fast too but has less BTU and burns up faster.
 
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ShawnLiNY

Burning Hunk
Dec 13, 2018
224
Ny
Just to ad on woodys suggestion pine can really help when burning not completely seasoned splits of hardwoods . Be sure to protect pine from direct rain contact ( especially end grain)
 

adatel

New Member
Feb 25, 2019
18
New Hampshire
I'm scouring the woods now, but it's slow work grabbing a bunch of small dead trees with the bark fallen off. They are dry though. If you can hook up with a tree guy and get some free Red Maple by showing up when they are cutting, it will get pretty dry by fall if you get it split and stacked single-row in the wind, top-covered, right away. It doesn't burn as long as more dense woods, but you are in a jam. Pine dries fast too but has less BTU and burns up faster.
Thanks for the tip!
 

begreen

Mooderator
Staff member
Nov 18, 2005
90,694
South Puget Sound, WA
What is the depth of the fireplace at around 30" from the fireplace floor? Is this an exterior wall fireplace?
 

weatherguy

Minister of Fire
Feb 20, 2009
5,832
Central Mass
To add to woody stoves advice ash will also season quick and is a really good wood to burn, 75% of what I burned this year was ash because I fell behind gathering wood.
 
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adatel

New Member
Feb 25, 2019
18
New Hampshire
What is the depth of the fireplace at around 30" from the fireplace floor? Is this an exterior wall fireplace?
Sorry for the delay - I was out of town: depth is 19 inches at 30” of height; hearth is 24” deep; so I have 43” to edge of hearth at that height. Also, fireplace is not on an exterior wall. It is in between the living and dining rooms with large passageways on both sides.

After everything I have learned here I am thinking about two options:
1. Blaze king Scirocco 30 with legs, fans and maybe external air duct
2. Woodstock Ideal Steel

I am away for 2-3 days at a time often and so the idea of being able to leave the BK running for 30+ hours (using the automatic primary airflow) would probably keep the house above 50 degrees even in winter. I also think the fans will do a better job of keeping the entire big room space warm.

As for the Woodstock, I like the bigger firebox which accommodates longer splits and more wood. I am worried about the lack of fans and I think it will take me more time to learn how to optimize.

Both of them should look good in my space in black. I would consider the BK King but I just can’t handle the pot belly aesthetics.

I need to find somebody to clean the current masonry chimney and then do the install including stainless pipe all the way up.
By the way, I have a propane water heater in the basement that vents into the same chimney... Problem?
 

begreen

Mooderator
Staff member
Nov 18, 2005
90,694
South Puget Sound, WA
By the way, I have a propane water heater in the basement that vents into the same chimney... Problem?
The stove will need a full stainless steel liner sized to the stove requirement. It can not share the flue with anything else.