New cabin heating plan

[NickR]

I will be putting up a new Katahdin cedar log cabin in central Maine this spring/summer ( with the insulation package) over a full basement. The cabin will be about 1250 sq. ft., 900 downstairs and a 350 ft loft upstairs. Cathedral ceiling in living room . I have unlimited access to wood (495 acre woodlot) After quite a bit of reading, my initial plan is to put radiant in the basement floor and baseboard radiant in the main floor and loft. To cover power outages and generator failures (and just for pleasure) I will put a wood burning stove in the living room. I try to buy quality but I am starting from zero knowledge about the various boilers, tanks, etc. I don't want any gas in the house; just an emotional holdover from a long ago tragedy. From what I have seen so far, the TARM gasifier with a storage tank looks good, but expensive. I can afford it but don't want to waste my limited retirement nest egg. The Lopi Leyden looks as though it would more than adequate for the living room stove. I plan an inside chimney with two flues, one for the boiler and one for the stove. I am handy but I don't want to do any of the heating work myself as I would rather be playing outside and building a barn.

My carpenter's HVAC guy says this plan is a waste of money and recommends a New Yorker boiler.

I solicit comments on this plan and all will be taken with an appropriate grain of salt. Thanks.

 

[swestall]

Well, there is no greater pleasure than a wood stove for many of us here. And in a cabin like you describe it should heat the entire structure easily. With modern stoves you do best having a stainless steel flue the size the stove needs. (most are 6 inches, some 8 inches) I would stay away from the downdraft refractory burn models as they are new and often difficult to operate. And, put in some type of backup heat, oil furance, heat pump, etc. A geothermal heat pump would be great and would handle AC as well as heat.
Take time to go and look at many models in stove shops. Brands, Pacific Energy, Quadrafire, Hearthstone, Jotul, Woodstock, Englander, Avalon, Morso and there are others.
My personal preference is for secondary burn tube and/or baffle stoves. (the above are all that) I'd say you need a stove with an output of about 55-60K/BTU. It would be a little more than you need sometimes, but what you need when it is colddddd.
If I had it to do today, I would build a masonary chimney with easily changeable stainless steel flues. Because, this would give me the look of brick or stone with the reliability and maintainability of the stainless.
Hope that helps, many others may chime in here.....

 

[begreen]

Nick, I've moved this to the boiler room so that you can get more exposure to your primary needs. You can post again in the Hearth forum specifically about a woodstove for the backup. There are several choices, but it will likely be a small stove given the house size.

The place is small so a wood-fired boiler in a well insulated cabin could be overkill unless there are outbuildings (shop, garage, greenhouse) that would be on the system. But I'll let the experts discuss what is available. Good luck.

 

[Jersey Bill]

NickR, I will withold comment on what the HVAC guy said, but it sounds to me like you are on the right track. There is an assumption that you plan on using wood as the primary fuel.
The wood gassifier is the way to go for efficiency, but the output it has to be balanced with storage, and the heat load of the cabin. With the gassifier going, all your heating and hot water needs will be met, so why would you fire the wood stove ? If you do, it will probably overheat the place. I recomend putting in a fireplace in the living room for enjoyment and thermal delight.

For a backup, I would put a cheap wood stove in the basement next to the wood gassifier and tie it into the same flue, but you can only fire 1 at a time. If you leave the basement door open the heat will rise up through the house or you can facilitate it with an airway.

 

[NickR]

Swestall- What stoves are "downdraft refractory burn" and did you omit Lopi because I had already mentioned them or because you think I shouldn't consider them?

 

[Eric Johnson]

Welcome to hearth.com and, by default, the Boiler Room.

I agree with the comments so far. Having both a wood gasfication boiler and a woodstove in a small place like that doesn't make much sense. As Jersey Bill suggested, you should have one source of primary heat and one automatic (electric or fossil fuel) backup. Being partial to hydronic heat, I'd suggest a wood boiler and then either a bare-bones gas or oil boiler for backup, or electric baseboard. A more rational approach might be a decent wood stove and an oil or gas boiler for backup, which gives you the option of adding the boiler later.

If you want the ambiance of a woodstove in your living space and you don't mind hauling wood into the house and ashes out, then go with option #2. If you want reliable, free central heat and hot water (after the considerable initial investment), then go with the wood gasifier and fossil fuel backup. At some point, it becomes a lifestyle choice that only you can make.

On boilers, you'll find a natural bias towards wood gasification on this board, but that's basically because most of us are central wood heating geeks and wood gasification is at the top of the technological food chain. A conventional indoor wood-fired boiler will probably cost half of what a modest gasification setup will run you. The trade-off is that with the conventional (i.e., New Yorker) approach, you'll burn about twice as much wood, produce a lot more pollution and probably have to worry about creosote and chimney fires. But if your house is in the middle of a 500-acre woodlot, those issues become less important than they are for those of us who live in town.

Finally, you should at least consider getting a combination boiler, which is to say one that burns both wood and oil. Many of the cheaper incarnations of this type of boiler are unsafe (IMO) because both sides share the same flue. It's legal, but unsafe. Another potential problem is that you've got both your primary (wood) head and backup (oil) depending on the same pressure vessel, so if it springs a leak in the middle of the winter, you suddenly don't have a backup. The upside is that you have the oil on rare occasions when you might need it in the winter (vacation), without having to invest in a separate boiler. If you go this route, look for one that has separate combustion chambers and separate chimney outlets for each fuel. Wood Gun and Tarm have boilers like this on the high end. Most of the other combi units are conventional technology.

 

[Gooserider]

[quote author="Jersey Bill" date="1201999726"]NickR, I will withold comment on what the HVAC guy said, but it sounds to me like you are on the right track. There is an assumption that you plan on using wood as the primary fuel.
The wood gassifier is the way to go for efficiency, but the output it has to be balanced with storage, and the heat load of the cabin. With the gassifier going, all your heating and hot water needs will be met, so why would you fire the wood stove ? If you do, it will probably overheat the place. I recomend putting in a fireplace in the living room for enjoyment and thermal delight.

For a backup, I would put a cheap wood stove in the basement next to the wood gassifier and tie it into the same flue, but you can only fire 1 at a time. If you leave the basement door open the heat will rise up through the house or you can facilitate it with an airway.[/quote]

This is an unsafe and ILLEGAL / Code Violation install suggestion, no matter whether you only run one at a time or not - this type of setup is very easy to make backdraft through the unused appliance and give a CO poisoning situation. The rule is ALWAYS "One flue per appliance" on wood fueled stuff, and most other things, with a very few limited exceptions... (furnaces and DHW heaters can share a flue if they are the same fuel type and are properly connected, and a few of the "multifuel" furnaces run both fuels up the same flue, but this is arguably unsafe)

The only way this would be sort of legal / safe would be if you physically disconnected the unused appliance and blocked it's flue opening - hardly a practical approach.

Gooserider

 

[Eric Johnson]

Don't know how I missed that, but it's true.

 

[Gooserider]

Another option that might work is to look at doing a "Masonry Heater" - this is a high mass brick structure, superficially resembling a fireplace that you burn a hot fast fire in, which heats up the masonry so that it then radiates the heat back into the home for the next several hours. There are constraints on location and design, but it sounds like what you are doing might work with one.

I have not tried one, but we have a few members on the Hearth that have them and are enthusiastic about them. It is a simple low-tech approach that claims extremely high efficiency. If you google for them, you can find lots of information, or use our search facility.

Gooserider

 

[ISeeDeadBTUs]

My read on your post is that you want quality in a hydronic unit, and you want a back up. I don't know ANYTHING about today's woodstoves nor fireplaces, but I would bet you could heat the entire LA with a big unit. But you are putting in radient, so that will be your primary heat.

Does anyone here know if they make a large soapstone stove with a coil in it? 'Cause if they do, you might be able to heat the storage tank while at the same time heating the house by convection. This way if you lost electric for circulating the water, you would still heat the cabin. But if no such beast is available . . . .

Be very careful on sizing when it comes to a wood-fired hydronic. Get an accurate heat loss calculation. I remember back in the 80's all the log kit salesman used to tell customers about the excellent R-value of logs. I also remember being in some expensive kits where the water came between the logs and ran down the inside walls. Davey Crokett had better accomidations! I'm just saying, make sure you get an accurate heat loss calc. Since I'm no pro at that stuff, I tend to compare anyone's situation to mine. And your's sounds similar. I have 4k [] of pex, 1800 of which is in slabs. My cathedral is 21' at the peak, and even with radient, that is tough to heat. I think thats where you want the woodstove/fireplace. Take the chill off the room kinda' thang.

That being said, I am using a small hydronic unit (100kBtu). The concrete slabs suck the heat outa the water, but once they are to operating, maintenance seems no worse than wood framed floors. In fact, if you put in a 6' thick slab, I'd bet you could go for a week without additional heat input before the house would become uncomfortable. But that's just me postulating . . .

But if you sink all that money into a woodfired hydronic, storage, mixing stations, Grundfos pumps, yada, yada, yada, you'd probably be able to tie in a back up oil for realativly cheap. You'd not need anything fancy.

Throw money and/or hassles obtaining the unit asside, if I were in your shoes, I'd be VERY inclined to go with a Vitolig200. To the best of my knowledge Viessmann doesn't really do the 'storage thing', though they do much smaller buffer tanks. If you went with the 200 storage could become quite important.


BTW . . . are you going to heat that barn???

 

[BrownianHeatingTech]

I will be putting up a new Katahdin cedar log cabin in central Maine this spring/summer ( with the insulation package) over a full basement. The cabin will be about 1250 sq. ft., 900 downstairs and a 350 ft loft upstairs. Cathedral ceiling in living room . I have unlimited access to wood (495 acre woodlot) After quite a bit of reading, my initial plan is to put radiant in the basement floor and baseboard radiant in the main floor and loft. To cover power outages and generator failures (and just for pleasure) I will put a wood burning stove in the living room. I try to buy quality but I am starting from zero knowledge about the various boilers, tanks, etc. I don't want any gas in the house; just an emotional holdover from a long ago tragedy. From what I have seen so far, the TARM gasifier with a storage tank looks good, but expensive. I can afford it but don't want to waste my limited retirement nest egg. The Lopi Leyden looks as though it would more than adequate for the living room stove. I plan an inside chimney with two flues, one for the boiler and one for the stove. I am handy but I don't want to do any of the heating work myself as I would rather be playing outside and building a barn.

Given the size building you have, an EKO25 is probably the best gasifier. I haven't dealt with them, myself, but there are several folks here who have them, and I don't recall that any are unhappy with the purchase...

A separate oil boiler would be your best bet for a backup. If you go with a direct vent boiler, you won't need a third chimney flue. Direct vent boilers use the burner fan to blow the combustion byproducts out of the house, rather than relying on chimney draft or a powerventer. Either a Smith DV-8 or a Crown Freeport ODV would be well-suited to your application, and both are high-quality boilers.

My carpenter's HVAC guy says this plan is a waste of money and recommends a New Yorker boiler.

As with others here, I'm going to withhold most comments on that, except to say that some folks are set in their ways and look at the initial cost more than the long-term investment. He's not "wrong," per se, but he's looking at the situation through a different "lens" than most of us use, which colors his perspective (just as our lens colors ours).

If he isn't a good fit for your needs, it may be best to find a different HVAC company to handle the heating install for your home.

Joe