Submitted by Birgit McCall on Wed, 12/21/2016 – 5:49pm
So, you’ve decided you want a masonry heater? I can’t say I blame you, because we LOVE ours. The masonry heater is far superior to any kind of fireplace I’ve ever been near in my life — and I’ve been near a lot of different types as I tend to cozy up to any available fireplace in the winter. I’ve put together this handy FAQ for you to answer some of your burning (ha ha ha) questions.
What are the benefits of a masonry heater?
- You make 1-2 fires per day (you want to burn as fast and hot as possible) … no adding logs to an existing fire and smoking up your house (see short video below).
- Load it, light it, let it burn (with the grate fully open), close the grate when you’re down to little blue flames, and you’re done (it takes between 45-90 minutes depending on the wood and log size).
- The heater will stay warm for 12-24 hours after a burn. If you’ve been burning every day, it can take 24-48 hours to fully cool down.
- It’s warm … ALL the time (as long as you’re making fires every day or two, that is). In the summer, we call it the masonry chiller, and it’s great to sit on when you’re overheated from being outside.
- It doesn’t need power, so it’s excellent for extended power outages.
- It can heat your whole house (really), except for maybe that bathroom on the exterior wall of your master bedroom at the far end of the house.
- If your significant other moves the firewood and makes the fires, it’s no work at all (I am in charge of cleaning the window glass, and all in all, I think it is a fair trade … am I right??).
- The heater doesn’t care what kind of wood you burn (hedge, poplar, pine, oak, etc.) — it’s all about the weight of the firewood for that particular fire. Smaller logs are better so they will burn faster … where is my beer can?
- The heater is 90% efficient (meaning that 90% of the heat energy of the wood comes into the house) … the remaining 10% is necessary to keep a draft going up the flue.
- There is very little (if any) creosote built up, as the combustion process is extremely effective.
So how does it work?
In a dramatically oversimplified nutshell, the heater is made up of a series of channels made out of refractory brick. When the fire is lit, the door grate is left fully open, thereby creating a “flow” of hot air that moves through the channels of brick (which absorb the heat from the air), back and forth throughout the heater, and finally out the flue (see construction photos above). Note in the video below how strong the draft is as the fire “leans” into the first channel. Our heater has thick soapstone slabs on the (heated!!!!) benches and the top, and is coated with a white stucco-like material. The benches can heat up to the point that you cannot sit on them directly, so I have cushions made of armaflex insulation sheets (steam pipe wrap) covered with 100% wool upholstery fabric.
How much wood do you burn?
Oh boy, thanks for asking. I love this sort of stuff! We can burn a maximum of 114 pounds of wood a day, or 57 pounds (see photo above of firewood bags … that’s 52 pounds) every 12 hours (if it’s super cold, we can sneak in another small fire, but we’ve never needed to). I purchased a scale so that we can weigh the firewood as we bring it into the house. We’ve had the heater since 2012, and we burn around 8,000 pounds of wood a year (almost 2,000 pounds so far this year)!
What are possible downsides?
- If you want to add one to your existing home, it might be easier to just build a new house (or hope that an asteroid hits your house so you are required to re-build).
- Here are some things that you might run into as you begin your retro-fit project:
- There might be a few walls where you want to put the heater. (see photos above)
- Your geothermal heat pump might be immediately under where you want to put the heater.
- You might need to hire a structural engineer to figure out how to support 14,000 pounds on the ground floor over your basement.
- You might need to hire commercial builders to cut holes in your basement slab, install new footers, posts, and I-beams, cut a hole through your living room floor, notch down your joists, put on a steel corrugated platform, and pour concrete on the platform. Thanks Bruce Bolliger and the team from Commercial Builders who did an amazing job! (This is all necessary so the heater can “float” independent of the rest of the flooring). (see photos above)
- You might not be able to find anybody local who knows how to design and build one. We had the great good luck to have Ken Matesz
(author of Masonry Heaters: Living with a Piece of the Sun)
design and build our heater for us (and live in our guest bedroom for a few months — he’s an awesome houseguest).
- Your house WILL be a dust-filled disaster construction zone for what seems like forever (or approximately 4 months — see photos above).
- It might be a wee bit expensive, but we live by the motto “do it right the first time, only cry once.”
Nope. Love it!