Sunday, 03 February 2013 16:00

Wood Burning Masonry Stove

off grid, living off grid, self sufficient, homestead, sustainableI’ve mentioned this appliance in other articles and shown a couple of pictures but the more use we get out of it the more I become enamored with it and it’s time we put this appliance on the “highly recommended” list of low energy desirable appliances. I’m talking about our custom built wood burning masonry kitchen stove.

At the time Laurie and I were making our move from city to country life I owned a commercial masonry construction company. In talking to a product salesman one day (a former mason himself) he told me I should check into Masonry Heaters as a heat source for our new home. I had heard of them before but didn’t really know anything about them.

I read everything I could about the heaters and in that discovery process I noticed that some of the custom designed ones had kitchen stoves and ovens attached to them. That is what this article is about, our wood burning kitchen stove.

off grid, living off grid, self sufficient, homestead, sustainableWe use our stove for cooking, canning, and heating our home. This stove was always intended as an alternative stove to our primary cooking source, the propane stove and oven.

Who knew at the time we built what the price of propane would be in a few years? It bounces up and down with the price of oil and I didn’t like the idea of being stuck and at the mercy of the big oil and propane companies so we decided to have a backup stove. I’ve never regretted that decision since.

When we aren’t using the stove its 42” cast iron cook top serves nicely as counter space. It sits right next to our propane stove. It has two top round plates that are designed to distribute the heat evenly in the entire round space but the whole top is obviously heated as well.

The wood burner is in the upper left corner with an ash cleanout directly underneath. You can burn any kind of wood from kindling size up to about 3” round. To the right of the burner is the 10” oven. We have cooked bread, roasted whole chicken, and even a few pies in the oven. The only trick we had to learn was to rotate the food dish occasionally in order to get it to cook evenly. Even with the masonry mass heated up from a long term fire before baking it is best in this design to rotate the oven dish.

Starting from zero in the morning you can have bacon frying in about 10 minutes and coffee boiling in twenty minutes.

off grid, living off grid, self sufficient, homestead, sustainableI’ve got a 6” fresh air PVC pipe that runs from outside the house, under the slab and up next to the firebox. That air is then taken out through the adjoining Masonry Heater mass via an air chamber built into it and then on up and out through a standard double wall stainless steel pipe and vented through the roof just like a wood stove.

We use this stove in the spring and fall (when the temperatures are only mildly cold) to heat the house because we don’t really need a lot of heat at that time of year. We also use it a few times during the winter to supplement or “add to” our masonry heater when the temperatures are nearing zero degrees Fahrenheit and our masonry heater struggles to keep up. We heat a little over 1400 square feet. It only takes two small armfuls of wood per day to heat the house or supplement the other Heater. Whenever that happens we automatically use it to cook with. In the fall when it gets cool it comes in handy to do pressure canning and heat the house and cook dinner all the same day!

The one drawback to this heater is that here in the mountains we have inversions frequently the year ‘round. If the temperature is over 40 degrees and we have an inversion this stove won’t draw. The inversion shoves all the smoke right back down the chimney and into the house. We’ve tried everything. The reason is that in this design the air flow is “indirect”. It goes by the fire and “pulls it up the chimney. In our Masonry Heater design the fresh air comes in directly under the fire and pushes it out the chimney. That design works every time. The indirect design works most of the time. It is unfortunately a design issue and there is nothing we can do about it without tearing things apart.

Laurie and I both highly recommend wood burning kitchen stoves to anyone that can burn wood where they live. It doesn’t matter whether it is a custom built masonry stove like ours or a manufactured stove. These appliances are very diverse and will give you a real sense of self sufficiency. How many people in your neighborhood wake up to the smell of bacon and coffee in a nice warm house when the power goes out?

If you are considering a custom built stove, check out the Masonry Heater Association Of North America on line. There are only a few masons qualified to design and build custom stoves and you will need to do your homework. This is a great place to start and to get ideas.

Ed and Laurie Essex live off grid in the Okanogan Highlands of Washington State where they operate their website  and Off Grid Works.

Published in Heating
Tuesday, 14 February 2012 00:00

Masonry Heaters

One of the big decisions we had to make when we were planning our new off grid home was what kind of heat we were going to have? We pretty much eliminated anything that would require electricity such as a heat pump or forced air furnace since we’re going to produce our own electricity with solar power. Ideally an underground home with passive solar design was the very best design concerning heating but Laurie may have put me underground about 6’ if I tried to put her in an underground house so we had to keep looking.

We considered geothermal but it wasn’t practical due to water availability concerns and again, the electricity required for the pump. We were trying to stay away from propane heat in the pursuit of sustainability.

We did have 40 acres of trees and wood heat was a consideration but what would be the best kind of apparatus to deliver the heat? I had heated for years with a wood stove and didn’t particularly like the unevenness of the heat circle. If you place them where you live (living room) it can get pretty hot up close. A wood furnace would once again have the need of electricity for the fan to circulate. Fireplaces are not efficient or effective with the possible exception of a Rumford.

off grid, living off grid, self sufficient, homestead, sustainableoff grid, living off grid, self sufficient, homestead, sustainableAt the time we were planning this new home I was fortunate enough to be self employed in the commercial masonry business. I was discussing the heating issue with a colleague one day and he asked me if I had considered a masonry heater for my primary heat source.  Well, I just told you I was the Owner but I never said I was a professional mason. He explained to me that there were other terms like Russian stove or Russian fireplace etc. I had heard of those before but didn’t know what they were. I started doing research as soon as he left my office.

The short of it is that we did indeed end up with a masonry heater as our primary heat source.  We also had a wood burning kitchen stove and oven built on one end of the heater. I can’t tell you how happy we are with our choice. These heaters are over 95% efficient. Some claim they are the cleanest heat source available in terms of emissions.

They burn so hot that all of the gases and toxins are burnt up before they go out the chimney. Once the fire is started they are virtually smokeless.

They work differently than a woodstove. When a woodstove gets too hot you have to damper it down and they don’t always burn as clean as you would like when that happens. You also have to keep a woodstove going 24/7 in the cold months.

off grid, living off grid, self sufficient, homestead, sustainableMasonry heaters are different. They are a solid mass of brick and/or stone with a unique course for the exhaust to travel from the firebox to the chimney. The exhaust chamber starts at the firebox and then winds through the mass of masonry before it exits out the chimney. This allows the masonry mass to be heated thoroughly in a short time. We burn our hot fire for about two hours and then shut it down completely. Fire out. The heated masonry mass then continues to emit passive heat for the next 10 hours. Passive heat is the most comfortable heat there is. It is the same type of heat the sun puts out. You can even touch the outer stone with your hand without getting burnt so they are much safer for children and pets to be around.

off grid, living off grid, self sufficient, homestead, sustainableBecause you only burn for two hours twice a day you save on wood. We are going to use about six cords of wood per year but we live in cold country. This heater has kept our house (1400 sf) at a comfortable temperature when it was down to -9 degrees F so far. We did have to close off two rooms that didn’t need to be heated. If we need more heat or if we don’t want to close those two doors we just light a fire in the kitchen stove. If I had this same heater in my old house I would only use about three cords per year. We have even learned to use our kitchen stove to heat the house in the milder temperatures like spring and fall. That takes about an armload of wood per day.

 off grid, living off grid, self sufficient, homestead, sustainableThese heaters have been around for hundreds of years. They were developed and are still quite popular in Europe. Mark Twain commented that they were the most comfortable heat he had ever experienced after a trip overseas. They were developed as Europe became more populated and wood became scarce. Short hot fires to heat the mass and then let the mass emit heat for hours afterward. Most of them had ovens and even platforms for sleeping attached.

There are six different types of masonry heaters. Ours is a Finnish Contraflow. Each type has unlimited design ability. They are all custom designed and built.

There is a downside to these heaters. They are expensive. I may not have had ours put in except I was in the business and was able to cut the costs considerably. You can’t imagine why they cost so much until you see one being built. They are complicated to build and require more material than you could ever imagine if you didn’t see it with your own eyes. There is a legitimate reason they are so expensive. I should also mention that you have to burn relatively small pieces of wood, not to exceed 4”. That means way more splitting than a wood stove or furnace.

You can build one yourself but I would caution you to do a lot of research on the design and size before you do. If you are going to hire it done like I did, make sure your designer/mason is qualified and experienced. This is too large of expenditure and too important to your well being and comfort to do otherwise. For references or research I would suggest you start at your local masonry supply store or visit the Masonry Heater Association Of North America on line. You might also look at Firecrest Fireplaces .

 off grid, living off grid, self sufficient, homestead, sustainable off grid, living off grid, self sufficient, homestead, sustainableAs an aside, we did put direct vent propane wall heaters in as backup if we have to leave the house for any length of time during the winter.

Ed and Laurie Essex live off grid in the Okanogan Highlands of Washington State where they operate their website  and Off Grid Works.


Published in Heating