Masonry Heaters: Hot and Green

   The heaters, a staple in European homes for centuries, developed a presence in North America in the past few decades. They allow people to burn a renewable resource – wood – so efficiently that one or two small fires a day can heat an entire home, and even provide somel cooking and hot-water needs.
   The ecological benefits caught the attention of the U.S. Green Building Council (USGBC). The nation’s arbiter of sustainable design lists masonry heaters as about the only acceptable wood-burning devices for those seeking LEED® (Leadership in Energy and Environmental Design) certification.
   And, because they’re masonry heaters, they offer an opportunity for those knowledgeable in fireplace installation to add a product line that’s attractive, functional and taps into the green building market.

PUSHING FORWARD
   Masonry heaters are a centuries-old technology in search of a market. Although archeologists believe the basic heater design dates back to at least the Dark Ages in Europe, standards for today’s heaters are quite rigorous.
   Norbert Senf, owner of Shawville, Que.-based Masonry Stove Builders, explains that, more than 20 years ago, the first people to build masonry heaters on this side of the Atlantic ran into a problem getting building permits.
   “There was simply no building code coverage at that point,” says Senf, who’s also the current president of the Masonry Heater Association of North America (MHA). “We started a task force with ASTM (the American Society for Testing and Material Standards) and we started writing a masonry-heater standard. The heater association grew out of that.”
   A volunteer association of heater builders, manufacturers, and suppliers, the MHA’s main provides information to members and the public. Along with maintaining an extensive Website, the association provides informal training during its annual meeting in North Carolina, and also offers a certification program.
   Despite that, Senf admits that the idea of the heater – a masonry inner core and outer skin, separated by a small air space/expansion joint – has been slow to capture the imagination of the building public.
   “When a lot of the old timers got started with this in the late 1970s and early 1980s, there was basically no information about these heaters,” he says. “It’s been growing slowly and it’s still not very big – but there’s been a lot more interest in it over the least few years.”
   Some of that awareness he attributes to simple longevity, but Senf says the combination of rising oil prices, increased awareness of environmental issues and the push toward more green building has also given the technology a boost.
   Many of his fellow MHA members agree.
   “I’d say in the last six months interest has gone up 100 percent,” says Eric Moshier, owner of Duluth, Minn.-based Solid Rock Masonry. “I’ve been doing around 10 a year, but I’ve already got 10 booked for this year, and it’s only just starting.”
   “It’s still a pretty small share of the fireplace market, but last year we built the most heaters we’ve ever built in a year,” says Mark Klein, a partner at Gimme Shelter Construction in Amherst, Wis. “It’s also a business that builds on success.”
   “Interest is growing,” agrees Steve Cohan, owner of the Eastbound, Wash.-based Hot Rock Masonry. “Certainly the Pacific Northwest is an ideal environment for masonry heaters, and in the years I’ve been involved I’ve seen continued growth.”

NO COMPARISON
   Comparing a masonry heater to other wood-burning devices is a bit like comparing a sports car and a pickup truck; one’s for show and the other’s a bit more practical. When it comes to heating, there’s little contest.
   “You’re just going to get a lot more efficiency and a lot more heat from the masonry burner,” says Michael Thronson, owner of Montpelier, Vt.-based Michael Thronson Masonry. “With a fireplace, a lot of the heat goes up the chimney. With a masonry heater you’re only having a fire once or twice a day.
   “You load the firebox with wood, light it, and let it burn until it goes out completely, so you’re burning less wood.”
   How much less wood varies, of course, but Moshier says when he made the switch from a wood-burning stove to a masonry heater, his consumption fell from 10 cords of wood a winter down to three.
   The other advantage is that a masonry heater provides a place to store the heat that’s generated. And, Cohan says a good masonry heater will burn at more than 1,100°F – a temperature that gasifies the wood inside and would melt a cast-iron stove.
   “With these other methods, there’s no method for storing the heat,” Cohan says. “Even if you have a catalytic-combustion stove or a pellet stove, which have high combustion efficiencies, there’s no way of storing that heat.”
   However, not only does that super-hot fire burn cleanly and completely, but the heat radiates out from the core and into the skin of the unit, which provides a way to hold the heat and let it go gradually.
   It’s the ability to release that heat steadily over several hours that also adds to the attractiveness of masonry heaters, says Doug Hargrave, owner of Mid-Atlantic Masonry Heat Inc. in Charlottesville, Va., and a regional distributor for Tulikivi, the Juuka, Finland-based manufacturer of soapstone masonry heaters.
   “Radiant heat is much-more-comfortable than forced air,” he says. “It’s like sunshine. The baby-boom generation is looking for more comfort, and that’s driving the interest in all types of radiant heating, including masonry heaters and radiant floor heating.”
   Still, masonry heaters aren’t for every person and every application. For instance, they’re seldom used in commercial buildings. Hot Rock’s Cohan suggests there are several reasons for that, from the fact that many businesses don’t need to be heated 24 hours a day to the ambiance a fireplace will provide to firms such as restaurants and coffee bars.
   However, there are exceptions. Gimme Shelter has a unit in its shop, and Bruce Alkire, owner of Horseshoe Bend, Idaho-based Bruce Alkire Masonry Heaters, says he thinks the heaters would offer more than a heating option with certain businesses.
   “If you had a business where you had a byproduct like cardboard or wood – something you could burn – you could put a masonry heater in and cut down on your heat bill and on your trash bill,” he says. “It would be the ultimate recycling system.”

A CERTAIN OUTLOOK
   The vast majority of masonry heaters, however, go in single-family residences, and most commonly in new construction.
   One reason for that is the need to incorporate the heater into the surrounding structure.
   “It really depends on the floor plan of the house,” says Michael Thronson. “Ideally, it’s designed around the heater. It really calls for an open floor plan where all the rooms are not very far away from the heater, which is centrally located.”
   However, just about all these masonry-heater builders say often times the people installing these devices have a green outlook, and are using the heaters as just one part of their overall push toward energy efficiency.
   Mid-Atlantic’s Hargrave says many people who are buying Tulikivi heaters are building custom homes and they’ve done plenty of research on what products and features they want to incorporate into them.
   “They’re really hands-on people in terms of the fact that they’re not turning over their building project to an architect or builder,” Hargrave says. “They’re not going into McMansions, but these are custom homes and they’re making the decisions on what goes into them.”
   Klein says Gimme Shelter began installing masonry heaters because he and partner James McKnight wanted to put them in the homes they were building.
   “We’re really focused on energy efficiency,” says Klein. “We incorporate a lot of passive-solar design features and renewable systems, but we needed to offer a bio-fuel choice because it’s essentially impossible for solar to carry our heating load through the middle of our winter.”
   Of course, most of these heater builders also retrofit some existing homes.
   “A retrofit can be done to heat part of a home,” says Thronson. “Or, if the home has a good, open floor plan it can be done. However, the heaters are fairly large structures and you’re taking up quite a bit of space, so with a retrofit it’s a little trickier to find a place where it works.”
   Hargrave says he’s seen the market for retrofits pick up some as the new housing market has declined, and Masonry Stove Builders’ Senf says Tulikivi masonry heaters work well going into existing spaces. Even with a retrofit, Hargrave says installing a masonry heater is a major project.
   “The only thing we retrofit is putting something in front on an existing fireplace,” says Hargrave. “Sometimes we have to beef up the floor system, or we have to run a liner up the chimney. Because of the foundation requirements and the chimney requirements, you’re very quickly doing major remodeling.”
   Because of the scope of these projects – whether a new installation or a retrofit – there’s a strong perception that masonry heaters are expensive … and they can be.
   “They’re more-expensive than other wood burning devices,” says Klein. “It’s an incremental cost over a conventional fireplace of $3,000-$5,000 if you’re comparing a similar level of finish.”
   However, he adds that even with some of his less-affluent clients there’s a willingness to invest in the better technology.
   “One of the drawbacks is that you’re looking at $15,000-$25,000 fairly easily,” says Michael Thronson. “But, if you look at central air or a radiant floor system, it’s pretty comparable. I’ve also heard people say you pay it back in about 10 years with your fuel savings.”
   Nor do the heaters have to be that expensive. Bruce Alkire, for one, is looking at ways to make the devices more-affordable.
   “I’ve got a 2’ X 2’ I’ve designed that I could put in somebody’s home for around $3,000,” Alkire says. “I’d like to build them for people who need cost-savings with their efficiency.”
 
THRIVING
   A contributing factor to the cost of these masonry heaters is the materials used for the exterior finish. Although stucco and brick are also common finishes, natural stone is an attractive option for many buyers.
   Some installers only recommend natural stone. Hot Rock’s Cohan is one of them.
   “I don’t recommend brick to my clients because of heat-transfer issues,” he says. “The density of brick isn’t as great as most stones. We use quartzite, sandstone and granite – anything that might fit into the overall design of the house.”
“I use a lot of granite,” says Solid Rock’s Moshier. “I also use a lot of taconite-based products from northern Minnesota. And, I’ve just started using thin-veneer stones on heaters also.”
   Senf notes that river rock and tile are also popular masonry heater finishes, although, as with Moshier, he’s starting to look more to thin veneer for this market, for a number of reasons. A key one is that 5” is about the maximum thickness recommended for the heater’s veneer, and many full-veneer stones are a full 6”. There’s also the added weight that needs to be supported – and the cost.
   “I think thin veneer is an ideal application,” says Masonry Stove Builders’ Senf. “You can put up a backing and add some strength with a tensile stucco.”
   Then, of course, there’s soapstone, a traditional material for these units. Heater builders such as Cohan say it remains their favorite stone, and with good reason: It has unique thermal properties that give it more heat conductivity than other stones.
   Mid-Atlantic’s Hargrave says it’s rare for people to contact him about a masonry heater and ask for an exterior that’s something other than Tulikivi’s soapstone, although some of that has to do less with appearance and more with other practicalities.
   The Tulikivi heaters are sold as complete kits approved by Underwriters Laboratories Inc. (UL) and come with a warranty. To use another stone would void the warranty, Hargrave explains.
   Those concerns aside, for stone shops looking to get into offering masonry heaters, either because the technology appeals or a client asks for one, the path doesn’t have to be too difficult. The MHA’s Website includes a membership list.
   “The first one I did, I didn’t do myself,” says Hargrave. “I hired a couple masons who’d done one before.”
   Another option is to purchase a kit. For instance, Senf builds and sells core kits, and companies such as Gimme Shelter license them from him. However, Senf’s help goes beyond that.
   “I’ve got a page of construction documents and if a consumer contacts me, I suggest they download the assembly and finishing instructions from the Website and have the mason evaluate them,” he says. “If the mason needs help on a bid, he can call me and I can give advice.”
   And, many of these builders will put in the core and leave it for the client’s local mason to finish.
   “There are a number of people who do that – put in the core in a day or two, and then let the local guy have at it,” says Solid Rock’s Moshier. “A mason shouldn’t have any problem laying up the brick or stone to finish it out.”
Is it worth the effort to take on a job building a masonry heater? Those who build them now believe the market will only get stronger in the future.
   “The world we’re in, in terms of energy supplies, is changing radically quite quickly,” says Klein. “In parts of the country that have forest resources, wood-fired heating systems that are low-emission, fun, easy-to-use and easy-to-live-with are going to thrive.”
   Senf puts it much more simply.
   “Whenever there’s a recession, we do really well,” he says. “Whenever the price of oil goes up, our phone really starts to ring.”

This article first appeared in the March 2008 print edition of Stone Business. ©2008 Western Business Media Inc.