- Published: 05 March 2007 05 March 2007
By K. Schipper
Client/Designer/Contractor: Cold Climate Housing Research Center. Fairbanks, Alaska
Masonry Heater Designer: Solutions to Healthy Breathing, Fairbanks, Alaska
Masonry Heater Installer: Stone Castle Masonry, Fairbanks, Alaska
Stone Fabricator/Installer: Alaskan Granite, Fairbanks, Alaska
FAIRBANKS, Alaska – Most of the time when a building client talks about serving as designer and contractor, people in the trades shake their heads and walk away.
The Cold Climate Housing Research Center (CCHRC) and its Research and Testing Facility (RTF), though, is anything but a normal project.
However, use of other natural stone, including granite and slate, in the facility adds to the structure’s good looks, as well as its energy-efficiency at it seeks LEED (Leadership in Energy and Environmental Design) gold certification from the Washington-based U.S. Green Building Council.
MAKING AN INVESTMENT
Certainly the client for this project is a little out of the ordinary. The CCHRC is a private, non-profit organization founded by the Alaska State Home Builders Association.
“Our original founders were all contractors in this state, and our primary support is from the Alaska Housing Finance Corp., a state-owned housing finance corporation,” explains Jack Hebert, CCHRC president and CEO, and the owner of locally based Hebert Homes/Taiga Woodcraft. “They invest back into the state, and this is one of the things they’ve chosen to support.”
Until the RTF opened, the CCHRC operated out of a small office in downtown Fairbanks. However, early on, the need for a building became evident. Hebert says the CCHRC is anxious to look at building products and processes now on the market, determine what’s working and what’s not, and even develop new products.
“We needed room for our field research,” he says. “There’s a tremendous variety of extreme climates here in Alaska.
“We have everything from places with temperatures similar to northern Minnesota that get 200” of rain a year, to those that have less than 6” of precipitation and take five times the heating degrees that northern Minnesota does – and everything in between. In all those climates, there are people living with challenges related to shelter.”
While Hebert stresses the organization’s focus on real-world solutions, the new building is located on two-and-a-half acres of leased land on the University of Alaska-Fairbanks campus, which provides its own benefits.
“The proximity to the university provides us with a valuable resource in people who can do the applied research we identify,” he says.
Because of its membership, Hebert says designing and building the 15,000 ft(2), two-story building was considerably easier than raising the $5.2 million it ultimately cost. A number of financial options were considered, but the organization didn’t want to carry a mortgage.
Along with the Alaska Housing Finance Corp., other contributors to the building include several foundations, companies such as Siemens Building Technologies, Inc., Dow/Corning, DuPont and Johns Manville, as well as the University of Alaska-Fairbanks, the U.S. Department of Agriculture’s Rural and Community Development Division, and the state of Alaska.
“Designing the building was not something unusual for our design team,” says Hebert. “For instance, the chairman of our board is a licensed architect in Anchorage, and we utilized the input of a number of people from the design community around here through a charette (design exercise).”
DESIGNING FROM EXPERIENCE
The end result is a building that incorporates both what Hebert calls, “the cutting edge of Alaska,” and tried-and-true processes that, from its earlier research, proved to be best for the Fairbanks climate.
The masonry heater that serves as the focal point of the building’s ground- floor entry and lobby area definitely falls in the latter category, improving on technology that dates back centuries.
“We’re fascinated with the masonry heaters and the possibility of using that kind of a unit for heating homes,” says Hebert. “The burn is very clean, they’re very safe, and they provide a nice, even, steady heat.”
While ultimately CCHRC would like to develop templates for refractory core heaters that can be taken into the smallest Alaskan villages, and even offer the possibility of cogeneration of heat and electricity, the challenge with the RTF unit was mainly one of size.
“The amount of BTUs (British thermal units) the unit is capable of putting out had to be sized with the amount of energy use that’s modeled for the structure,” Hebert explains. “We also put a water jacket in the heater to provide warm water to supplement the hot water for our radiant-heat system.”
To translate the organization’s goals into reality, Hebert – as project superintendent – chose two local subs, Solutions to Healthy Breathing, owned by Bill Reynolds, and Stonecastle Masonry Ltd., owned by Dan Givens.
“Both are members of the (Randolph, Vt.-based) Masonry Heater Association of North America,” he says. “Dan is a master stone mason who did the finish work and Bill is an innovative guy. He was also involved in our ventilation strategy for the building in terms of circulating and filtering the air.”
Reynolds explains that he first became interested in masonry heaters when his wife’s asthma required him to find an alternative to the common wood stove. He installed his first design in his own home three years ago.
“I go to Austria every year and I designed mine with the help of a mason over there,” he says. “We then sampled it for a year and found it was very efficient and very clean.”
Reynolds adds that no requirements were specified going into the RTF project, other than that the interior be capable of being copied. For that reason, that part of the heater is based on a design created by Tom Stroud, now senior manager of codes and standards for the Hearth, Patio and Barbecue Association (HPBA), in 1988.
The interior design was built from 135 pieces of cast refractory cement and the same fire clay that’s used in fireplaces, which is rated to 2,600°F. The firebox generally reaches temperatures of 1,800°F -2,100°F, literally gasifying the wood.
“It never really hardens because the internal works of a heater are constantly in motion so when it’s very, very hot it won’t crack,” Reynolds says. “Inside the veneer there’s a space of probably a quarter-of-an-inch because the inside expands that much.”
To enhance the efficiency of the masonry heater, Reynolds also incorporated a German design that features nine different chambers. As the air passes from one chamber to the next around the heater, more heat is given up to the veneer and more gases are burned, rather than going up the chimney. Testing by the federal Environmental Protection Agency (EPA) in the mid-1990s showed it to be the best available technology.
“The real objective is to burn all the gases completely,” he says. “We knew this design worked, but we changed the air differently, so it can come from either outside the building or inside the building. And, we can direct the air within the fire chamber itself using a valve system I designed.”
Although Reynolds makes the design process sound fairly simple, Givens says the end result was what he describes as extra-heavy, from several standpoints. Not only does the masonry heater weigh 12,000 lbs., but it can burn 90-100 lbs. of wood at one time, and it’s supported by 3” X 12” beams in the building’s basement.
Givens adds that the masonry heaters are really the latest trend he’s seen in supplemental home heating as his customers have gone from fireplaces to wood stoves to the heaters.
“The pendulum is swinging back toward centering a masonry heater in the house,” he says. “The hearth is now called the heart, and it’s the focal point. You come in and get warm and people like that ambiance.”
The technology has also been helped by the fact that some countries, such as Finland and Canada, are giving tax credits to people who put them in their homes.
Because masonry heaters work by radiating heat, an exterior that can hold the heat generated on the interior is very important, Givens and Reynolds agreed that the exterior should be an Alaskan river rock.
“We wanted a high-density rock that would hold the heat as much as possible,” says Reynolds. “It required some research, because you don’t want to get the wrong rocks and heat them too quickly or they’ll explode. We brought the finished heater up to temperature over about two weeks to slowly drive the water out of the mass.”
Givens says he had attended a masonry-heating seminar where various stone and masonry products were baked, then had their temperatures checked over a couple hours. While using a local rock helped with the LEED certification, and was considerably less expensive than importing soapstone from Finland, he says using it on the exterior of the header did not compromise heat retention, either.
“We know soapstone is the best, but it just happens that quartzite sandstones are within a degree or two of the soapstone, and most of these local river rocks are quartzite and dunite and gabbros,” Givens says. “The exterior walls of the masonry heater are about 6” thick and incorporate stones from 2”-22” set in Portland cement.”
To take the efficiency of the heater a step further still, Givens also assisted mason Mike Buberge in installing slate tile flooring in the entire lobby area.
“If you stay on a regular schedule of firing a masonry heater, everything in the room will come up to a stasis point,” Givens explains. “Everything, top to bottom, will be within two or three degrees. The slate flooring helps ensure there’s little temperature fluctuation.”
KIND OF SECURITY
While the CCHRC was certainly interested in the practicality of its masonry heater, the use of natural stone also provides great aesthetics for the lobby, and helps enhance the look of the rest of the building.
Givens says he worked hard to make the heater, which measures approximately 6’ X 3’ X 6’6” with an attached wood box, as attractive as possible.
“I’ve been working with river rocks for quite a few years, and it’s almost like putting a puzzle together,” he says. “You develop an eye for color; you have to blend the color so it flows together. And, with this, a lot of the stones have intrusives, so each is unique, and many people find they have a favorite rock.”
To help finish the heater, Hebert turned to Alaskan Granite. He says owner Alec Turner has worked with him in many of the homes he has built over the years, and the design called for black granite hearths on the front and back of the heater, and a black granite cap on top.
“There are 6” risers of black granite on both sides,” says Turner. “I took a blank headstone and ripped it down and polished it on all sides by hand.”
Both they and the cap feature beaver-chiseled edges, and Givens says the granite offers a nice transition from the river rock.
Turner was also responsible for seeing that a commemorative plaque with the organization’s mission statement was sandblasted and installed on the back of the heater, and he cut and installed the 17’ workstation in granite for the building’s library.
While he isn’t sure of the reason behind the Absolute Black for the workstation, Turner does know the practical reason behind using the stone for the building’s windowsills, which he also fabricated and installed.
“That’s mainly because our UV (ultraviolet) is so intense,” he says. “If you do a conventional painted windowsill, you’ll have to repaint it every couple years.”
Turner adds that the remainders of the windows are trimmed in kiln-dried natural birch from the area. “It’s quite a nice contrast,” he says.
Hebert says the use of the stone trim is more than just for contrast. It doesn’t hurt that it’s a green material, but he says it also gives the offices more of a homelike feel.
“Natural materials have what we call a soul,” says the organization’s president. “They have something that touches us psychologically; there’s a warmth to them that’s important in an environment like this that’s cold and dark in the winter. When you have warm rock, there’s a kind of security that may go back to when we lived in caves.”
Still, there’s also a lot of science to be learned from the masonry heater, Reynolds, the stove’s designer, says. Because of the extensive monitoring throughout the building, he’ll be researching its performance even more closely than he did the one in his own home.
“It’s so closely monitored that we’ll know how many BTUs we’re getting from a pound of wood, based on the moisture,” he says. “Because our furnaces are monitored, we’ll be able to determine how much heat we’ve contributed by reading the decrease in energy used compared to the outside temperature. Over a year’s time we can figure quite closely how much wood we needed and how efficient it was.”
Judging for the response it generated at the building’s opening, Givens says it’s already gone a long way in acquainting people with masonry heaters.
“I ended up standing at it for five hours answering questions,” he says. “It was amazing the questions people asked. There’s a lot of interest in it because of that.”
Alaska Granite’s Turner’s excited by what he sees as the building’s potential for improving home construction throughout his state.
“Maybe some of these guys will start understanding they can be doing more,” he says. “This should bring them information to help them put out better-quality projects.”
This article first appeared in the February 2007 print edition of Stone Business. ©2007 Western Business Media Inc.