Direct vent propane stove

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Ashful

Minister of Fire
Mar 7, 2012
20,058
Philadelphia
Hey folks,

I'm looking at options to put a propane stove with minimal diameter direct vent here:

basement stove.jpg

Don't be fooled by that old Jotul parts stove, there's no thimble there. More on that at the end.

Since I really don't like the idea of ventless for indoors, I'm wondering what direct-vent options might exist for a pretty stove to go here, which have the minimum vent diameter to punch thru a 24" thick mud and rubble wall. Whereas the good square face stones are red shale, a good fraction of the rubble buried within is granite, so the drilling will not be easy.

What are some options with a very small vent tube diameter?

I already have a gas stub into the back of this fireplace from below grade outside, and while it's been condemned due to corrosion, I believe I could withdraw it and replace with a stainless stub, with some digging and some effort.

Unimportant to this topic, but for full disclosure, there actually IS a thimble above the lintel. It's , which plumbs into the chimney of the fireplace above, where I have an Ashford 30, but it's not easily accessible from inside the fireplace. You can see it as the black circle in the top left corner of the photo below, above the lintel on the outside of the fireplace, in this older photo taken during renovation of the basement:

scan126.jpg
 
The smallest option for DV units is a colinear 3” flexible aluminum vent kit. In most instances both the intake & exhaust need to be run to the DV cap, although some units can use a shorter intake that only runs part way. The liners attach to a colinear to coaxial adapter which in turn attaches to the stove flue collar. There may be other options, depending on stove manufacturers, but for the most part the double 3” is the smallest available.
 
Thanks, Daksy!

Does "direct vent" always imply coaxial? An appliance that would draw interior air but allow exhaust just a few feet above grade thru a stone wall would be ideal, if it allowed me to drill a smaller hole thru the stone wall. Not sure if such a thing exists, or if I could just call any small hole thru a stone wall a "chimney".

Trying to avoid having to plumb up thru the adjacent chimney, which is over 40 feet up from here and already plumbed with my wood stove liner, and also not easily accessible from this location.
 
The type of stove you’re thinking about is a B-Vent, not Direct Vent. BV stoves use air from inside the home for combustion. The exhaust still has to be @ 4” diameter. This type will cause drafts in your home as that combustion air has to be replenished.
 
Yeah, same trade-off as woodstove with/without Outside Air Kit (OAK), but thought it might have allowed me to get away with a smaller hole thru the wall. Oh well.

Thanks, Daksy! Now I know I should search on direct-vent stoves, if pursuing this.

I'm half tempted to pull the block-off plate out of the chimney above, and see if I can find another buried thimble leading into it from this foundation below. Some of the hollow cavities planned and built into stone walls of this age are surprising and downright frightening. Unfortunately, it's the wrong time of year to be pulling apart the chimney to my woodstove above.
 
What about vent free..
They've just always scared me, honestly. I know it's not going to instantly kill any of us, but there's no denying they increase CO levels in the home, among other combustion byproducts.

This basement rec room space is used as sleeping quarters for kids and teens, when they have friends over. Don't really like the idea of one of them turning on that stove and leaving it on while the sleep, if it's ventless. We have hydronic baseboard down there, so the stove isn't needed unless they forget to "Permanent Hold" the thermostat schedule on that, but you never know what kids will do when you're not watching.
 
They've just always scared me, honestly. I know it's not going to instantly kill any of us, but there's no denying they increase CO levels in the home, among other combustion byproducts.

This basement rec room space is used as sleeping quarters for kids and teens, when they have friends over. Don't really like the idea of one of them turning on that stove and leaving it on while the sleep, if it's ventless. We have hydronic baseboard down there, so the stove isn't needed unless they forget to "Permanent Hold" the thermostat schedule on that, but you never know what kids will do when you're not watching.

ther is a remote thermostat that you can program and set a temperature it will automatically go off
 
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Maybe I should give them more consideration. My thinking was that, if all possible, I'd rather have it vent outside. I think I could get a 3" core bit thru 24" of stone, but I've honestly never had to do it before, so it's a gamble.

The bedding mortar in these walls is just mud from the back yard, as there were no local lime kilns when this stone was laid in 1734, and Portland cement hadn't even been invented yet. It means that, in addition to the likelihood of hitting granite, stuff inside the wall can shift during/after drilling. It would be good to avoid all of that, if possible. The walls are about 60/40% red shale and granite.
 
How big (volume) is the space. I’m wondering what air quality you would get if you could add a heat recover ventilator or (ERV) and go with ventless.

How much would it run?
 
How big (volume) is the space. I’m wondering what air quality you would get if you could add a heat recover ventilator or (ERV) and go with ventless.

How much would it run?
Good questions. It's a large house, but if we had doors closed (as you might do with a bunch of kids making noise all night), the space containing the heater might be reduced to as little as 6000 cubic feet, worst case. It would run only when kids are down there, as this is their place for playing video games, movies, billiards, sleep-overs, etc.

We have hydronic baseboard down there, separate zone on the oil-fired boiler, which can keep the space plenty toasty. But it's very slow to heat up, which is where this little unit would come in, we'd likely rely on this stove alone when heading downstairs to play a few rounds of billiards, not wanting to wait for the whole space to heat up via baseboard heaters.

Never thought of an ERV, and actually know very little about them. How would that be easier to plumb thru 20 - 24" of stone wall, than a direct-vent heater?

If there are ventless units with remote thermostats, I'm wondering if I might find one that has a timer function, such that it can lock out for a programmed period after a certain amount of usage. This might alleviate some of my concerns, with having a ventless unit going all night in a closed space, as not all of the kids are responsible to watch this manually.
 
Thanks, Woodsplitter! Will check it out.

If sticking a ventless in that space, where would you be looking, in terms of brands and retailers? I have never shopped gas stoves, at all.
 
Good questions. It's a large house, but if we had doors closed (as you might do with a bunch of kids making noise all night), the space containing the heater might be reduced to as little as 6000 cubic feet, worst case. It would run only when kids are down there, as this is their place for playing video games, movies, billiards, sleep-overs, etc.

We have hydronic baseboard down there, separate zone on the oil-fired boiler, which can keep the space plenty toasty. But it's very slow to heat up, which is where this little unit would come in, we'd likely rely on this stove alone when heading downstairs to play a few rounds of billiards, not wanting to wait for the whole space to heat up via baseboard heaters.

Never thought of an ERV, and actually know very little about them. How would that be easier to plumb thru 20 - 24" of stone wall, than a direct-vent heater?

If there are ventless units with remote thermostats, I'm wondering if I might find one that has a timer function, such that it can lock out for a programmed period after a certain amount of usage. This might alleviate some of my concerns, with having a ventless unit going all night in a closed space, as not all of the kids are responsible to watch this manually.
The ERV could be ducted. So you get to choose the location of the holes. 50-100 cfm of fresh air would probably be ok. Don’t over look electric heaters for this application. Up front and install price is just so much cheaper.
 
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I went to 2 different stove shops that sold gas inserts.. I forget the brans we purchased.. im at the shop right now.. I can give you the brands we went with.. they have never given me trouble.. they are 6 years old now
 
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IIRC, Vent free units are not allowed in bedrooms.
This is in a basement recreation room, not a bedroom, so no legal concern there.

But good point, as I'm sure kids will be occasionally sleeping down there for parties, etc. This is why I had originally been against the idea of ventless. But if there's a means of setting a time-out, then I'm less concerned about it.
 
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This is in a basement recreation room, not a bedroom, so no legal concern there.

But good point, as I'm sure kids will be occasionally sleeping down there for parties, etc. This is why I had originally been against the idea of ventless. But if there's a means of setting a time-out, then I'm less concerned about it.
Sometimes the spirit of the law is more important than the letter of the law...
 
Sometimes the spirit of the law is more important than the letter of the law...
How do you mean? Again, this is not a bedroom. In fact, it's two floors removed from the closest bedroom, and three floors removed from the rest.

My statement that "occasionally kids will sleep down there" applies to probably every living room in America, in which a gas appliance might be installed.
 
How do you mean? Again, this is not a bedroom. In fact, it's two floors removed from the closest bedroom, and three floors removed from the rest.

My statement that "occasionally kids will sleep down there" applies to probably every living room in America, in which a gas appliance might b

How do you mean? Again, this is not a bedroom. In fact, it's two floors removed from the closest bedroom, and three floors removed from the rest.

My statement that "occasionally kids will sleep down there" applies to probably every living room in America, in which a gas appliance might be installed.
Everybody knows what I meant. Full disclosure, I am not a fan of Vent Free at all, in any room, so I will excuse myself from this discussion.
Forgive me if my reply seemed flippant but as the manager of a fireplace company it seems like everyone is more concerned with form over function and I am constantly dealing with arrogant homeowners and contractors who want to "bend the rules". It gets frustrating to always be defending an installation that is technically correct, but doesn't fit their design plans.

Good luck with your project, Happy New Year!
 
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For the record, I'm not a fan of vent free either, just see my first several posts in this thread. But for this occasional-use application, it may be the most suitable choice.

Its real intent is to run < 1 hour to heat up the space when we run down to play billiards, or while waiting for the hydronic baseboard to heat up and take over. This is why I had inquired about thermostats with a time-out function.

Also, do note that this is a fairly well-drafted space, despite being a basement. In fact, I can see straight out to the back yard around the perimeter of the basement door (installed 1734) with it closed, the stove being located only 15 feet from that door. So, if there were ever an ideal application for these completely-legal appliances, this would be it.
 
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I had a chance to do a little shopping online today, but I'm not finding anything vent free that will allow installation into an alcove like the fireplace foundation shown in my first post:

Direct vent propane stove


There are several reasonably priced options on there, but all I've found seem to require 36" to 48" free and clear above stove top.

Do note that the entire "ceiling" of that alcove is several timbers laid in parallel, it's not just the single timber lintel.

edit: just ran downstairs and measured lintel: 58" from floor to bottom of timber. Could achieve 36" above a 22"H stove, but most seem to be closer to 28"H.
 
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I had a chance to do a little shopping online today, but I'm not finding anything vent free that will allow installation into an alcove like the fireplace foundation shown in my first post:

Direct vent propane stove


There are several reasonably priced options on there, but all I've found seem to require 36" to 48" free and clear above stove top.

Do note that the entire "ceiling" of that alcove is several timbers laid in parallel, it's not just the single timber lintel.

edit: just ran downstairs and measured lintel: 58" from floor to bottom of timber. Could achieve 36" above a 22"H stove, but most seem to be closer to 28"H.
Is it a fireplace or an alcove. Call the lintel a mantle and shield it???? Vent free logs????