MASONRY HEATERS AND
A MASONRY HEATER ALLOWS YOU TO HEAT YOUR HOME WITH WOOD
IN A UNIQUE WAY.
The main thing that distinguishes a masonry heater is the ability
to store a large amount of heat. This means that you can rapidly
burn a large charge of wood without overheating your house. The
heat is stored in the masonry thermal mass, and then slowly radiates
into your house for the next 18 to 24 hours.
If you burn wood fairly rapidly, it is a clean fuel. If you try
to burn it too slowly, the fire will change from flaming to smoldering
combustion. The burning process is incomplete and produces tars.
Atmospheric pollution increases dramatically. This is important
if you are planning an energy-efficient house. The average energy
demand of your house will be quite low. For most of the time, it
may require only 1 to 2 kW of heat. For most conventional woodstoves,
this is below their “critical burn rate”, or the point
where they start to smolder.
Masonry heaters fill the bill perfectly. If you need even a very
small amount of heat, such as between seasons when you simply want
to take off the chill, you simply burn a smaller fuel charge–yet
you still burn it quickly. The large surface is never too hot to
touch. You have a premium radiant heating system with a comfort
level that simply cannot be equaled by convection or forced air
Common Questions About Mansonry Heaters:
Do Masonry Heaters have fans to circulate the heat?
No - Masonry Heaters are radiant heaters. As in floor radiant
heat or as in an older building that had hot water radiant heaters
spaced around the home or office - no fans needed. Actually, a fan
would cool the area as a fan would cool you on a hot sunny day.
What makes a Masonry Heater work?
The Masonry Heater consists of a firebox and a lambrith of flue(heat
exchange) channels. The flue gasses serpentine through these channels
giving off heat to the masonry before reaching the exit flue. After
the fire is out and the damper is closed, the masonry mass gives
off this captured and stored heat to the living space needing heat.
What if it gets too hot?
No problem. A heater cools slower in a warm environment and
faster when it is cool. So if the heated space reaches 75 degrees
or more, the heater does not cool as fast as if the space was 65
degrees. If that happens, you would skip the next one or two scheduled
firings. Also, you could open windows for some nice fresh air or
turn a fan on to chill the air. This is not a problem.
Do Masonry Heaters have a catalytic converter?
No - catalytic converters work on wood stoves where there is
no mass. The catalytic converter is actually a miniature masonry
mass that increases the flue temperatures for more complete combustion.
In Masonry Heaters the entire structure is a heat storing masonry
mass, so the temperature is high enough for a complete burn. Tested
Masonry Heaters on an average burn cleaner than all wood stoves
- even those equipped with catalytic converters and second only
to pellet stoves.
What kind of wood do you burn in Masonry Heaters ?
You can burn any wood properly dried to less than 20 percent
moisture and split to proper size in your Masonry Heater. Size depends
upon the heater design - ask your heater designer. Usually two to
three inches in diameter minimum to five to six inches maximum.
How much wood does a Masonry Heater burn?
That depends on the model. Smaller heaters can heat 1000 sq.
ft. with 15 pounds of wood two times daily for a total of one cord
per season in Western WA. A medium heater could heat 1500 to 1800
sq. ft. with a 30 pound load two times daily for a total of two
cords per season. A heavy duty heater could heat 2200 to 2800 sq.
ft. using 45 pounds two times a day for a total of three cords per
season. The first year, most people use 30 to 50 percent more wood
than is needed and with time learn how much fuel to use for their
needs. New heaters for the first season use more fuel because moisture
in the heater uses some of the heat energy. Also, new homes have
a higher moisture content and need more heat to feel comfortable.
Why do Masonry Heater cost so much?
Consider a Masonry Heater an investment compared to a masonry
fireplace. True, they cost $4,000 to $5,000 more than a fireplace.
However, a masonry fireplace is at best 10 percent efficient, where
a Masonry Heater exceeds 60 percent efficiency and up to 80 percent.
Part of the cost assures performance. Masonry Heaters are complex
and we use more materials, higher quality materials and more than
twice as much labor to construct as a comparable size fireplace.
The original cost is greater, but the added value and heating convenience
and resale value is always greater than the original cost.
What are the drawbacks to a Masonry Heater?
1. To some people it is the cost.
2. To others, it is the delay in heat output versus fueling
cycle. Masonry Heaters unlike other heat sources need to be recharged
(fired) on a 12 or 24 hour cycle. Today's fire is tomorrow's heat.
The fire lasts about 2 hours every 12 hours.
3. To most, it is the short fires - not enough time to enjoy
What are the benefits?
1. Easy to use, convenient, low tech and it works.
2.Clean heat for people with allergies or asthma etc. - no indoor
3. Low cost quality heat and efficient.
4. No power needed to maximize heat output.
5. Safe, never too hot to touch, except the metal or glass doors
when the fire is burning.
6. Can be custom designed to your needs.
7. Can be custom designed to any decor.
8. Value added for resale and aesthetics.
9. No utility bill - uses renewable fuel.
10. Good for the environment. Does not add to the greenhouse effect.
11. Exempt from EPA, Certified in WA, CO, MN and other controlled
12. Reliable old technology proven in Europe over 300 years ago.
(Not an unproved theory.)
13. Standard model core kits can be installed by any quality mason.
14. Low maintenance. Yearly inspection minimum, but if properly
used the cleaning cycle may be needed only every two or three years.
15. Unlike other heater sources, bakeovens and heated benches (hearth)
are common in Masonry Heaters.