Increasing fireplace efficiency without an insert?

[IHDiesel73L]

This is our fireplace:



I'm well aware that open fireplaces pull heat out of a house while operating and the only way to really heat a home with a fireplace is to stick an insert into it. That said, I just can't do it-right now the fireplace opening is about 24" x 40". Going with an insert would shrink the viewing window to not even of a quarter of what it is now. I have a super efficient Buderus wood boiler and I have a small wood stove at the other end of the house on the first floor, so the fireplace is almost purely ornamental/atmosphere, but a little more efficiency and a little less draftiness when not in operation certainly would not hurt. The biggest ticket item on the list would be sealed doors:

https://www.wilkeningfireplace.com/

These guys make a door that is essentially like putting a wood stove door on a regular sized fireplace opening complete with pyro-ceramic glass, cam-locks and a sliding draft control:



They would run about $2,100 for my application. I also found this company which makes what they claim is a more efficient grate along with steel firebacks which I had planned on trying anyway:

https://www.gratewalloffire.com/

My fire box is about 32" wide at the rear so I was going to go with their 31" wide grate and matching 31" wide by 1/2" thick fireback. The final consideration is the chimney. Our fireplace has a massive 13x13 square clay tile liner which is about 20' from the throat of the fireplace (from the smoke shelf to the start of the clay) to the top. I was told that putting a sealed door on the fireplace opening (and thus limiting the intake air) would cause the draft to suffer, and that the gases would lazily make their way up the large flue, cooling as they went, forming creosote. This did make some sense to me, so I did a little research on fireplace flue sizing. Utilizing the 10% rule my flue size should be 11" diameter or about 96 square inches as opposed to 169 square inches now. I would plan on installing a stainless flex liner and then pouring in vermiculite between the stainless liner and the old clay.

Doing all of this work myself would cost just shy of $4,000, which is about the same price as a good insert and liner with me doing all of the work. However, I figure the benefits would be as follows:

• Sealed doors would mean no more conditioned air escaping (in summer and winter) when the fireplace is not in use.
• Elimination of the strong BBQ pit smell in the living room on humid days.
• We would still have the ability to simply open the doors, draw the screen and enjoy an open fireplace.

What I am most curious about is how the fireplace would perform with the doors closed while operating. Again, if we're sitting by it, 90% of the time it will be open, however, usually before going to bed, I'll let the fire die out to the point that it is safe to close the tempered glass doors that we currently have. With the new ceramic glass doors/draft control, liner and efficient grate/fireback I could load the firebox up, close the doors and turn the air down just like with a woodstove and see how much heat is given off. I certainly don't think it will be as much heat as an insert, but I have to believe it will be more efficient than it is now.

 

[farmer steve]

Google Grate Wall of Fire. One of my wood customers say he really likes his. Not sure how efficient.

 

[mijdirtyjeep]

I would look into the doors more before buying. I was always told not to shut the glass doors when running a fireplace as they have large chimneys and it would slow the smoke down to the point of condensing in the clay liner. Hence the need for a smaller liner when running a woodstove/insert. I am not sure how accurate this is, but something to look into.
Before my insert I would let the fire die down to coals before bed. Then almost close the dampener so it was just cracked. That allowed the fumes (what’s left) to still go up, while keeping a little more heat in.

 

[ElevatorGuy]

I think you’re nuts for potentially spending 4K to maintain the view and try to make a wood evaporator more efficient.

If you want the look and heat, Put a gas log set in.

 

[H-Ranch]

You have a large, beautiful fireplace and I can appreciate wanting to keep it. I had the same dilemma when we bought the house we are in now.

I tried a tubular grate with a fan attached to get some additional heat from the fireplace, but even that was only enough to maintain the house temperature on a day in the 30's. It would not raise the temp or even maintain on colder days.
I do not know how well what you're looking at would work.

I ended up building an OWB and now have the best of both worlds (for *ME*, not for everyone.) I'm sure that even an insert would not be able to heat my house design as well as the OWB does. I have significantly less than $4k all in. Maybe another location with a wood stove would work on your situation instead of an OWB also. (Edit: looks like you have that covered. Just enjoy the fireplace and let the other wood burning devices do the work. )

I wish you luck and hope you end up as happy as I am with whatever you choose.

 

[mga]

i have used something like this for years in our fireplace. Ours is an older version (i could not find any pics of it) but these things do throw a lot of heat and we use it with glass cabinet doors, which we keep closed when a fire is going. yea, i know, they say not to do that. I also made sure the door frame is sealed with insulation to eliminate as much air leaking possible.

 

[NSMaple1]

To each their own of course. I would do an insert.

 

[Del_]

I suggest a beautiful small free-standing wood stove would look beautiful on that hearth and provide backup heat should there be a need.

 

[IHDiesel73L]

First off I'd like to say that I appreciate the responses rather than just "buy an insert..." Its an interesting discussion.

Google Grate Wall of Fire. One of my wood customers say he really likes his. Not sure how efficient.

I actually was planning on going with that in my first post until I found this:
https://www.texasfireframe.com/
Which is supposed to work on the principle of the "Physicist's Fire" or the "Slot Fire":
https://grandpappy.org/rrfire.htm

I would look into the doors more before buying. I was always told not to shut the glass doors when running a fireplace as they have large chimneys and it would slow the smoke down to the point of condensing in the clay liner. Hence the need for a smaller liner when running a woodstove/insert. I am not sure how accurate this is, but something to look into. Before my insert I would let the fire die down to coals before bed. Then almost close the dampener so it was just cracked. That allowed the fumes (what’s left) to still go up, while keeping a little more heat in.

As I said before I think going down to an 11" round flue from the 13" x 13" square is critical. That's also a big part of the expense-the whole kit from Rockford Chimney including liner, chimney cap, firebox fitting, cement and pour-in vermiculite is about $1,500. I was to install an insert the liner would be mandatory-if I was to just continue burning the open fireplace it would still be a very good idea in terms of longevity for the chimney and ease of cleaning.

I think you’re nuts for potentially spending 4K to maintain the view and try to make a wood evaporator more efficient. If you want the look and heat, Put a gas log set in.

I'd take a sledgehammer to the whole thing before I put a gas log in it.

i have used something like this for years in our fireplace. Ours is an older version (i could not find any pics of it) but these things do throw a lot of heat and we use it with glass cabinet doors, which we keep closed when a fire is going. yea, i know, they say not to do that. I also made sure the door frame is sealed with insulation to eliminate as much air leaking possible.

Burning with the doors closed is not recommended with tempered glass doors because tempered glass cannot take the heat and will eventually fail. Wilkening Doors can be ordered with pyro-ceramic glass-the same glass that is used in woodstove windows.

I suggest a beautiful small free-standing wood stove would look beautiful on that hearth and provide backup heat should there be a need.

I already have a small stove on the other side of the house in the kitchen area-the point of all of this is to just lose less heat from the house when using the fireplace.

You have a large, beautiful fireplace and I can appreciate wanting to keep it. I had the same dilemma when we bought the house we are in now. I tried a tubular grate with a fan attached to get some additional heat from the fireplace, but even that was only enough to maintain the house temperature on a day in the 30's. It would not raise the temp or even maintain on colder days. I do not know how well what you're looking at would work. I ended up building an OWB and now have the best of both worlds (for *ME*, not for everyone.) I'm sure that even an insert would not be able to heat my house design as well as the OWB does. I have significantly less than $4k all in. Maybe another location with a wood stove would work on your situation instead of an OWB also. (Edit: looks like you have that covered. Just enjoy the fireplace and let the other wood burning devices do the work. ) I wish you luck and hope you end up as happy as I am with whatever you choose.

Essentially what I'm trying to do here is create what amounts to a built-in insert that can be used as a conventional fireplace as well. Fitting the Wilkening Doors to the front of the fireplace seals the firebox and regulates the airflow into it (from the house) via the same type of sliding air control on a wood stove, which, just like an insert, solves the problem of sucking all of the heat up the chimney. The next problem then becomes how to ensure there is enough draft given the lesser airflow into the firebox. I'm trying to research how woodstove designers arrive at the flue sizes they do-more to come.

 

[moresnow]

Sooooo. If your mind is essentially made up. Get er done! Let us know how it ends up performing. Nothing you intend to do can't be un-done.

 

[gumneck]

I've never known anyone that had one but have heard of them....Heatilators
https://www.heatilator.com/browse/fireplaces/wood-fireplaces

 

[ElevatorGuy]

Sooooo. If your mind is essentially made up. Get er done! Let us know how it ends up performing. Nothing you intend to do can't be un-done.

Gonna be a huge waste of money! The sledgehammer sounds fun at this point.

 

[IHDiesel73L]

Sooooo. If your mind is essentially made up. Get er done! Let us know how it ends up performing. Nothing you intend to do can't be un-done.

Its not made up yet-still just playing around with ideas. If my mind was made up I would have bought everything already.

Gonna be a huge waste of money! The sledgehammer sounds fun at this point.

Maybe, but I'm the one earning it so I suppose I'm entitled.

 

[Be Stihl]

I had a very similar condition, fireplace with 12” square clay flue tile. I ended up buying a used Jotul wood stove and added a flex liner from Rockford chimney supply, a great place. They also have calculators to help with sizing. I used a 7” solid stove pipe to a Tee, then square flex liner which I wrapped in insulation to save cost over vermiculite. I fabricated a block off plate to sit up in the smoke shelf that allows the flex liner to pass through. Works great in my application for about $2,000 total stove and pipe.
So I totally understand wanting the fireplace intact. But for heat I have to agree that a wood stove is the way to go.
Also just to mention, the house I was raised in had a fireplace with a sort of heat pipe grate with fan and glass doors as you mentioned. Looked good, heated half heartedly.

Sent from my iPhone using Tapatalk

 

[bbxlr8]

I have 2 FP & a woodstove in the current house. The last one had a huge central masonry FP with a built-in heatilater insert that did a great job. I have been debating your outlined issue in the current family room FP that we use for fun and just 'cause I like burning. I generally avoid using on "polar vortex" type days to avoid sucking all the hard-earned heat out of this bigger chimney and considered a nicer looking WS for this one.

Another point to consider: I am currently using a full glass door screen that is nowhere near that $2k cost (more like $250-500) and these can be still very functional and decent looking.
I leave just enough open to not get a massive draft when cold and have no issues with buildup in this flue. There is a provision for air control venting across the bottom.

 

[IHDiesel73L]

I have 2 FP & a woodstove in the current house. The last one had a huge central masonry FP with a built-in heatilater insert that did a great job. I have been debating your outlined issue in the current family room FP that we use for fun and just 'cause I like burning. I generally avoid using on "polar vortex" type days to avoid sucking all the hard-earned heat out of this bigger chimney and considered a nicer looking WS for this one.

Another point to consider: I am currently using a full glass door screen that is nowhere near that $2k cost (more like $250-500) and these can be still very functional and decent looking.
I leave just enough open to not get a massive draft when cold and have no issues with buildup in this flue. There is a provision for air control venting across the bottom.

Where did you get the door? Is it tempered glass? From all of the reading I've done tempered glass won't stand up to the heat and will eventually fail. The ceramic glass accounts for a lot of the cost.

 

[ElevatorGuy]

Maybe, but I'm the one earning it so I suppose I'm entitled.

You’re right about that.

 

[bbxlr8]

"Where did you get the door? Is it tempered glass? From all of the reading I've done tempered glass won't stand up to the heat and will eventually fail. The ceramic glass accounts for a lot of the cost."

This one came with the house and used for going on 11y but I bought one for my first house in 93 and used it for 7+. Never saw the need for the heatilator central unit mentioned above in between.

Most of the ones that they sell with glass will stand up which is what motivated me to point this out. I can tell you I have had it CRANKING in this FP as I have hickory oak etc in my woods and no issues whatsoever w/ the glass.
Now the ceramic glass like in stoves is awesome stuff but overkill for this IMO.

 

[spotking]

We have had the Great Wall of fire with the steel plate behind the grate--- for 6-7 years and really like it--not cheap --the steel plate helps radiate heat 8-10 feet out into the room --plus you can enjoy the fire--

 

[ChoppyChoppy]

Where did you get the door? Is it tempered glass? From all of the reading I've done tempered glass won't stand up to the heat and will eventually fail. The ceramic glass accounts for a lot of the cost.

2 pieces of ~24x20 ceramic glass should be in the $800 area. A glass shop shouldn't have trouble replacing the glass in your doors.

If it was me, I'd just look at putting a draft damper in the firebox and not fussing with the rest.
Close it when not in use and don't worry about efficiency when in use.
If you want efficient, use your wood boiler.