Trying to get an adequately large gas stove for an old building

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Kip

New Member
Nov 19, 2014
5
Illinois
Hi, I'm new.

It's gotten cold quickly, and we weren't prepared. We have been looking to add a big gas heating stove to our apartment, and now we have to make a decision. We have been told by the city that we must choose a direct vented heating unit - no compromise on this, we are right downtown and we must follow their directions. I am looking at direct vent gas stoves and direct vent gas furnaces, but I'm afraid of buying too small and regretting it.

The building we are in is 100 years old and brick. We have r30 insulation under the roof, but the place is far from airtight. It's a 64x20 apartment, so we're at just under 1300 sq ft. I'm seeing a lot of gas stoves rated at 40k BTUS, and their literature says they will heat 1800 sq ft. I'm just afraid that they aren't talking about 1800 sq ft of old construction with dismal R value.

I'm looking at getting a Napoleon GDS50, at 44K BTUs. But I'm also looking at a Williams 60k BTU direct vent furnace, and though the furnace isn't nearly as attractive, I will be sick if I buy the smaller heat output and we're still too cold. I have two little girls and the place has hardwood floors, so I want them to be able to feel warm in bare feet for most of the winter. This apartment is very open and has a loft feel, so I would prefer a visually appealing system to keep the homey feel. But if a gas stove just can't keep a space this size good and warm, I'll have to go with the uglier and warmer system.

I am planning on putting some hydronic baseboard heat in the bathroom and another spot or two so that the distance from the main heat source won't leave those rooms uncomfortably cold. We also have mini-splits wirth heat pumps, which handle fall and mild winter well, but last year they were overpowered and there were nights that it got down to 51 degrees in our apartment. My wife and girls had to move out while I patrolled the building at night trying to keep pipes from freezing.

If you have recommendations on certain stoves or furnaces, I will happily hear advice, but here is my big question - will at 40k BTU gas stove heat a poorly insulated 64x20 brick box? If you are sure that a gas stove that size can handle it, please tell me. If you don't think so, please tell me. We have an opportunity to purchase a system tomorrow, and our weather is warming back up for long enough to get it delivered and installed. But I must choose a system tonight and order tomorrow. And I really appreciate any knowledgeable input. It got down to 11 degrees outside last night, and I know from living through last winter that we must get more heat in here right now.

I know there are tons of variables, so let me give you some more info to answer possible questions about our setup. We're in the upper floor over a business, and there is no heat under our floor at the moment. The 64x20 is divided into rooms, but most rooms have sliding windows built into the walls above the door level, so that heat can exchange easily from room to room. There is no possibility of putting forced air into the apartment, and no ductwork either. It will require a heat source in the main room, and of course the further from it the colder it will be. I'm in southern Illinois, so the winters aren't deadly but they're colder and more bitter all the time. I myself am comfortable with a room that only gets above 70 in the winter, but my wife and kids like it pretty toasty, and since the thermometer can hang below zero for over a week during winter here, I want to be able to cope with that and feel like I did the right thing.

Thanks again for any help with this decision. I will check back and see what you all write before I place my order.
 
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40K won't do it. You'll need DOUBLE that & higher efficiency than a DV gas stove will give you.
Most are about 75% efficient, so a 40K BTU (INPUT) will yield 30K BTU (OUTPUT)
A poorly insulated building will lose heat at a rate too fast for a smaller unit to keep up with.
I'd say your choices are to go with the furnace/boiler or get more than one stove...
 
Thanks for your answer. Two stoves would be far too expensive (though I'd love to have them), so I'm left with the direct vented furnace, which is a Williams 600773, at 60k BTU. While I've heard some good things about direct vented stoves, I'd never even heard of a direct vented furnace. If anyone can tell me what they know about the Williams brand, or about the reality of a direct vented furnace, please chime in. I hate to buy something mysterious. And even then, this still falls short of the 80k you are suggesting.
 
By the way, the building is brick exterior, plaster over brick interior, so we don't even have the insulation that drywall would provide. And covering the brick walls would take away the look we love, the reason we want to be here. So more insulation isn't in the cards.

Thanks.
 
Thanks for your answer. Two stoves would be far too expensive (though I'd love to have them), so I'm left with the direct vented furnace, which is a Williams 600773, at 60k BTU. While I've heard some good things about direct vented stoves, I'd never even heard of a direct vented furnace. If anyone can tell me what they know about the Williams brand, or about the reality of a direct vented furnace, please chime in. I hate to buy something mysterious. And even then, this still falls short of the 80k you are suggesting.

A direct vented furnace is just like a B vent furnace except that direct vent pulls the combustion air from outside. B vent uses indoor air for combustion. Both vent the combustion air to the outside.

A question - since you have the mini splits already, would a couple of larger electric space heaters work to provide supplemental heat on those colder nights so that you're not having to purchase a larger system on such short notice?
 
A direct vented furnace is just like a B vent furnace except that direct vent pulls the combustion air from outside. B vent uses indoor air for combustion. Both vent the combustion air to the outside.

A question - since you have the mini splits already, would a couple of larger electric space heaters work to provide supplemental heat on those colder nights so that you're not having to purchase a larger system on such short notice?


No, the mini-spilts quit entirely when it's really cold, so I have to have a primary heat source. We ran large electric space heaters all last winter - sometimes three in the main room alone - and the apartment got down to 51 degrees. They are pretty good air conditioners, but I knew they weren't going to be our main heaters.
 
No, the mini-spilts quit entirely when it's really cold, so I have to have a primary heat source. We ran large electric space heaters all last winter - sometimes three in the main room alone - and the apartment got down to 51 degrees. They are pretty good air conditioners, but I knew they weren't going to be our main heaters.

I Only question I have is that Williams and other wall furnace makers do make units that are less powerful, in the 30,000-35,000 BTU range. Given the size of your space, would it make more sense to put in two of those to get better heat distribution, or is that cost-prohibitive?
 
We considered putting in two furnaces, one at each end. By next winter we will have heat from the main floor under us, buffering us from the cold a little. We ended up buying the 60k BTU Williams DV furnace, and we're really hoping it will keep us comfortable through this winter, because if it can do that it should have an easier job every winter after. I would have much preferred more attractive heating. This apartment would have had a totally different feel with a good-looking stove, but we couldn't justify spending for ornamentation over heat output. I usually find a way to get things like I want them, but circumstances got us far behind on our schedule, and then I had to shoot quickly to keep the place liveable. Thanks everyone for your input, I'm really praying that it's money well spent, and that once the furnace is operational and we have some baseboard heat to keep the distant rooms warmer, we'll be happy with the route we took.
 
I have a reasonably well insulated but drafty 1800sf house, which is adequately heated with a 30K BTU stove in the living room and two 7500 BTU "housewarmer" DV heaters in the back bedrooms (one in each bedroom). The third bedroom is heated by a through-the-wall fan taking warm air from the living room. None of the heaters have too work too hard even in the coldest winter.
 
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