Catch airform on fire?

[mkrepel]

Greg,

From the pics you have posted, I agree that a masonry heater would be a nice addition to your new home. Of course I believe this is probably true of any house/decor where there is space available for this use. With many commercially available units, once you have the core built of fire brick, the outer (heat storage) masonry can be whatever works for your decor. I think it is a good opportunity to use local river rock, but anything from red brick to adobe to ceramic tile have been successfully utilized for this.

The fly ash (burning embers from a normal woodstove) are captured in the serpentine sections of the flue where all of the heat transfer takes place. The result is a very clean exhaust plume that is also only about 150 degrees F. Of course, the flue has to be built so that the fly ash can be removed periodically, but almost all of these appliances have that provision built in.

The cost of a masonry heater is considerably higher than the cost of a metal woodstove. However, I would think the advantages could outweigh the cost if it means you can get away with a less expensive airform treatment. There are also the intangibles like personal comfort. The lower external temp of a masonry heater should be more comfortable than the normal metal wood stove.

Mike

[mkrepel]

Greg,

I had a couple of final thoughts on this issue.

I think you will end up with a fairly long stove pipe (the height of your dome roof + wall height + extra to get the pipe high enough to disipate the smoke before it gets back to the ground) so the chances that a still-burning ember will reach your airform are really pretty small even with a normal wood stove. You can also install a spark arrestor cap on your flue which will nearly eliminate this issue.

I have noticed that normal wood stoves and fire places (especially with chimney caps) do drip liquid (mostly condensed water mixed with creasote and solids from the smoke, I believe) onto the roof surface. I don't think this would damage your airform, but it is an unsightly mess.

Mike

[Big D]

I visited Monolithic about 18 months ago and had a nice experience with the tour and a lot of my questions were answered... but one of the things that stuck out to me at the time was the concern over a wood stove. I was told that indoor wood stoves, fireplaces, and even gas ranges were not really recommended, because of their O2 consumption inside of a relatively well-sealed dome.

Is this not as much of an issue as I understood it to be, or are there ways to mitigate the drawbacks? I'm starting to get closer to making a final decision, and it would be a bit easier if I could plan on a far cheaper/simpler indoor wood stove for primary heat, rather than having to deal with moving heat from a more expensive and complex outdoor stove.

As for "roof" fire hazards, I assume that most paints, stuccos, or other coverings designed for exterior use would largely take care of the problem? Or would only certain types, like stucco or bricks, provide sufficient exterior fire protection?

[3dO]

I visited Monolithic about 18 months ago and had a nice experience with the tour and a lot of my questions were answered... but one of the things that stuck out to me at the time was the concern over a wood stove. I was told that indoor wood stoves, fireplaces, and even gas ranges were not really recommended, because of their O2 consumption inside of a relatively well-sealed dome.

I am interested in a Forno Bravo type wood fired pizza oven in my dome. I would like to know if I should plan for some additional air intake to make up for the fire.

[mkrepel]

Most folks who design/build masonry stoves strongly recommend an outside air source. This means that air is drawn directly from outside the structure through a dedicated pipe that dumps directly into the base of the appliance. I believe most conventional wood stoves recommend a similar setup. In some locations this is actually part of the building code, so depending on where you are, you may not be allowed by local code officials to install one of these without the outside air source.

The purpose of dedicated air sources is to provide adequate O2 to the fire without depleting O2 in the home. It also ensures that the stove has proper air flow in today's tightly sealed homes. That way the stove will draw properly and you don't have the spectre of carbon monoxide emissions into the home. Of course, with a masonry stove the supply line and the chimney generally come with shutoff valves so that no air (especially cold, outside air) is drawn through the stove. This step saves the heat that has been stored in the masonry. The only drawback of this system is that you must remeber to open the damper and the inlet before you try to light a new fire.

I don't think a properly installed and vented wood stove or masonry stove should present any problems in a dome as long as the occupants follow all of the basic rules pertaining to wood burning appliances. It is a good idea to install an O2 sensor in the home too. Doing so would provide a warning system for the eventuality that somebody didn't do something correctly or the appliance is not operating properly. Again, this may be a code requirement in some areas.

I believe all of these precautions also pertain to any heating appliance that uses fuel whether it is natural gas, heating oil, or wood. Of course, electric or solar provide heating without this worry, but they are not always practical and nothing beats the warmth of a wood fire on a really cold day.

I say , if you want a woodstove, go for it, but take some precautions.

Mike

[Mcfish]

Big D; Here are a couple of links to green building blogs. All the blogs recommend very tight construction. It is atrue that MD may be as tight or tighter than many of these other homes; much depends on the details at the penetrations. But all these sites discuss how to provide make up air, HRV or ERV systems, and how to avoid stale air syndromes. In California, it is a law that you have to have a CO monitor in the house, They cost about $30, and many are combined with smoke alarms/detectors. So do the right planning, keep asking these questions, and read the blogs to find out what you haven't heard about yet. MD's are great because the thermal mass holds heat; even if you had a bad gas main or clogged flue, you could vent the entire house through windows and doors in a few minutes, and the mass would warm the new air up quickly. The advantage is that much of the effort stick builders go to in order to make their house tight is unnecessary in an MD; air has a tough time traveling through solid concrete. Spray foam is one of the best tools air tight builders have to seal small openings.
http://www.greenbuildingadvisor.com
http://www.greenbuildingtalk.com/Home.aspx

[Necoras]

Big D,

I'm not huge into wood burning stoves myself (aside from something like an aesthetic fireplace), but I will be putting in a studio for working with glass over a flame. One of the number one safety issues with lampworking is sufficient ventilation. This means I need to be able to pull out several hundred cfm of air from the studio and replace that air. My studio will need a sufficiently large exhaust vent to the outside, and an inflow vent far enough away from the exhaust that I'm not circulating the exhaust. The situation will be similar on any appliance that's burning up oxygen and producing dangerous fumes. You obviously don't have the same noxious fumes coming from wood as you do glass, but you don't want your house filled with smoke or CO either.

Ideally you'll have a stovepipe of some sort that goes to the top of your dome and exhausts heated air out of your house. You'll also need a vent near ground level (or at the very least on the roof 10-20 feet away from the exhaust pipe's exit) to pull in replacement air. As mkrepel mentioned, many fireplaces will have a place for that air to go directly into the appliance. This helps to make sure you aren't cooling your house while trying burn wood to warm it. The situation with the glass studio is a bit different as I want all of the air in the room to be switched out regularly.

Good luck.