What size wood stove?

[buickanddeere]

A small stove stoked regularly burning clean and bright burns less wood per btu of room heat and creosotes the chimney less. Than a over sized stove stuffed full of wood , dampered down and left to smoulder all day in an effort to only have to fuel 2-3 times a day.

 

[TractorGuy]

US Stove Barrel Stove Kit - For Life Out Here

 

[Egon]

This had been tried many times, but for various reasons I don't think it's a good idea. Not much useful heat is actually gained from it. It must be able to withstand having no circulation with a hot fire during a power failure or pump failure. You can send scalding hot water to the radiant tubing repeatedly and weaken it. The heat exchanger takes up useful room in the stove and is always heavily coated with creosote because it runs much cooler than the fire.

It's just hard to mix water with fire in a wood stove and expect long term operation or practicality.

Actually the mixing of water and fire is quite well established.

 

[Larry Caldwell]

WoodChuckDad:

Is the orientation of the house as showed in your plan (glazing to the North ?) If so, that would definitely contribute to a significant loss in energy efficiency... If the main glazing faces south, you would get solar gain and with a heavy concrete slab would be perfectly set up for passive solar.

A heavy concrete slab is not absolutely necessary. I have 150 sf of U.36 window space on the south wall. A few years ago I retrofitted the south side of the house with a tile floor over cement backer board, and R22 insulation in the crawl space. At at a guess, that's about 2 tons of thermal mass. In the winter the sun does a nice job of heating the floor, which will keep the house warm until after sunset. To minimize heat loss I installed double cell honeycomb blinds that we close at night. The wood stove has a firebox big enough to accommodate an 8" log. Our routine is to heat with wood in the evenings, with an 8" log at bedtime. This will hold coals all night. In the morning I pitch several small (2") rounds onto the coals and give them a quick whoof with the bellows to get them flaming. By the time we are showered and dressed for work, the rounds have burned down to coals. We open the blinds and the sun heats the house all day. It's still warm when we get home from work and build a fire.

We actually have central heat, but keep the thermostat set at 60 degrees. The only time it kicks on is when we are gone for long periods of time. My wife is very pleased that the comfort level of our home doesn't change when the power goes out. Water is gravity feed, but hot water is electric. Without power we can heat a laundry tub of water on the wood stove and mix it with cold water to take a bath, wash dishes, etc. We also cook on the wood stove.

Wood heat is the original solar. All the heat came from sunlight.

 

[Larry Caldwell]

This had been tried many times, but for various reasons I don't think it's a good idea. Not much useful heat is actually gained from it. It must be able to withstand having no circulation with a hot fire during a power failure or pump failure. You can send scalding hot water to the radiant tubing repeatedly and weaken it. The heat exchanger takes up useful room in the stove and is always heavily coated with creosote because it runs much cooler than the fire.

It's just hard to mix water with fire in a wood stove and expect long term operation or practicality.

You have to have the right stove design. The heat exchanger tube does not belong in the firebox, it should be brazed to the steel back of the stove. A hybrid solar/wood hydronic system needs a tempering valve to avoid scalding people or the hydronic system, and a means of dumping excess heat. Nobody needs 200 degree hot water. If the heat exchanger circ. pump fails during a power outage, so will the hydronic system circ. pump, so that is not a problem. You can always drain down the heat exchanger to keep it from boiling.

A hybrid solar/wood hot water system requires either an operator or a programmable microcontroller to function properly. The failures were just people who lacked the skill to design and build a functioning system. I have an engineer friend whose water heater has been turned off for 18 years. I have another friend who built a system without a PMC. It takes a full time operator to run it.

 

[WoodChuckDad]

US Stove Barrel Stove Kit - For Life Out Here

I might be going out on a limb, but I'm pretty sure my wife will veto me making the wood stove.

 

[WoodChuckDad]

There will be an opportunity for passive solar in the main room. But there is twice as much square footage on either side of that room that will not get much sun exposure inside, due to design. The solar gain should make the heating system more efficient, but it won't be enough to heat the whole house. As for the crawlspace....I hate them. I'd much rather have the slab built and pay a bit more up front.

 

[Egon]

The insurance company may not approve of a non certified barrel stove.

 

[WoodChuckDad]

The insurance company may not approve of a non certified barrel stove.

I have no intention of making my own stove. I have enough headaches.

 

[dmccarty]

There will be an opportunity for passive solar in the main room. But there is twice as much square footage on either side of that room that will not get much sun exposure inside, due to design. The solar gain should make the heating system more efficient, but it won't be enough to heat the whole house. As for the crawlspace....I hate them. I'd much rather have the slab built and pay a bit more up front.

I hate crawl spaces as well and our house has a concrete colored slab even though the house is built on a slope. The interior of the foundation was filled with 67 stone after the waste pipes were installed. The 67 stove self compacts to 95% or some such and we have not had any settling of the slab. The slab is a colored concrete which is our finished floor. The slab does hold the heat from the stove and sun. Flip side is that if we let the house get hot in the summer or cold in the winter it takes longer and more energy to get the house temperature where we want it. Trick is to not let the slab temperature get out of whack for the season.

We though about putting in heating in the floor but for our climate it did not make money sense. Further north, I think it would make a great deal of sense to put in the floor heating.

We do have passive solar on the house which warms up the slab and it works. The roof eaves are sized so that winter sun light and enter the house but during other seasons the sun cannot enter the house. Simple, cheap and effective. While we have six inch thick walls with 1" foam on the exterior, we poke big holes in the walls for windows and doors. We love the view but we are likely a bit cooler in the winter as a result...

We try to heat primarily with wood using a stove that is for 1800 square feet in a 2400ish square foot house. Square feet is really not a good measure though, volume should be used instead. We have 10 foot ceilings so our volume is a bit higher than a house with 8 foot ceilings. Our house has a fairly open plan and the stop is roughly in the center of the house and we have found that the hot air from the stove naturally moves around the house. This mostly works for us but when we have below normal colder days, the wood stove does not keep the house as warm as the wifey and kids would like. Meaning the stove might keep the living room in the mid to upper 70s and not 82. The far side of the house will be 5-10 degrees cooler depending on outside temperature and if the kids keep their doors closed. We have always talked about adding a second stove for these really cold days but the reality is that this only happens for a few days a year and an extra stove is not worth the cost and space.

There is a six inch PVC pipe that runs under the slab from an exterior wall to behind the hearth. The pipe brings in combustion air for the stove and it works really well. If the fire is not running I don't feel any air moving from the pipe but if the stove has a fire you can feel the air being pulled into the house. We don't feel the cold air because it is in back of the stove and either used by the fire or heated before getting further into the room.

Later,
Dan