Green Right Now

Fireplace Alternatives: Masonry Heaters and Pellet Stoves Give More Heat, Less Smoke

By Barbara Kessler

Ah, winter. Time to curl up with a book, sip hot cocoa, snuggle before a toasty fire — and watch it suck the warm air out of the house faster than a Blue Norther blasting through an open window.

It’s true, unfortunately. That wood fire crackling away in your typical open fireplace – the sort that’s been built into the majority of suburban and urban American houses — is mostly decorative. Its heating properties are nearly illusory. Sure it is warm standing right next to it, but while it burns and smolders down it operates mainly as an energy drain, fueling itself from the air inside the house and sending it up the chimney in smoke.

The heat gain from the fire might be 10 percent as some of the warmth pushes into the surrounding room. But if you leave the damper open for the evening to assure that the fumes from the embers escape, you’ll lose that gain and then some.

It’s no secret, this abysmal heat performance by fireplaces. The Department of Energy (DOE) calls fireplaces “energy losers” unless they have been specially equipped with high-efficiency energy inserts, house an EPA-rated wood stove or pellet stove or have been replaced by an energy-producing masonry heater.

“Traditional fireplaces draw in as much as 300 cubic feet per minute of heated room air for combustion and then sent it straight up the chimney,’’ reports the DOE’s consumer energy website. describes this phenomenon as a “clash of technologies ” between modern homebuilding and traditional fireplaces: “In a house that is to be tightly-constructed and well-insulated so it will be cozy and easy to heat, the home buyers want to have a traditional open fireplace, a device whose design was state-of-the-art a couple of centuries ago.”

People working in home heating and building trades know this sooty little truth about fireplaces quite well. A family would be “10 percent better off if they built their fire in the front yard and looked at it from the window inside,’’ says Jerry Frisch, owner of Lopez Quarries in Everett, Wash., a longtime builder of masonry heaters, which burn wood like fireplaces but do so much more efficiently.

So what’s the alternative for people who like the ambiance of a fire, but perhaps more importantly want to heat their home? Short of foregoing the drama of the fire and relying only on your forced air furnace, experts point to these three solid, environmentally sound choices:

The DOE gives the masonry heaters — sometimes known as Finnish fireplaces — the highest marks because they produce “more heat and less pollution” than any other wood- or pellet-burning device. (So we’re saving them for last. If you can’t wait, check out our slide show of masonry heaters.)

A gas-log fireplace, which can be fitted with fans to circulate the heat, might have made the list, but the fuel is not renewable. It emits greenhouse gases and still loses much of its heat to the simple dynamics of the fire, which gulps room air to burn. While some heat may be forced back into the room, much of it still goes up in smoke. If you have a gas-burning, faux log system, add glass doors to cover the face and minimize heat loss.

Pellet stoves, on the other hand, win good reviews from government people studying and assessing heating systems. They are compact little animals that burn compressed pellets manufactured from sawdust or other natural products, even hemp grass for those who don’t want to compromise on sustainability.

Pellet stoves are tightly closed systems so they can burn their fuel at high temperatures, thereby burning cleanly and emitting few, if any, greenhouse gases. In this way, they produce a lot of heat for the amount of fuel used. Newer models of pellet stoves can heat at 85 percent efficiency. And for people who may view a pellet stove as an imperfect addition to their home décor, they can be installed to use an existing fireplace chimney.

“Pellet stoves are still very popular and are the cleanest and most efficient means of heating with wood. They can either be free standing or inserted into an existing fireplace,” says Scott Haase of the DOE’s National Renewable Energy Laboratory in Golden, Colo.

Pellet stoves became a popular option a few years ago for homeowners wanting to escape total reliance on gas and electric heating systems, but ran into some difficulty when sudden demand outstripped supply causing difficulties in obtaining either the stove or its necessary compressed pellet fuel. Some people complained about being dependent on the manufacturers of pellet fuels, who didn’t have a lot of price competition.

Still, the DOE estimates there are about 500,000 pellet stoves in use in the United States today. Pellet stoves have some downsides: Their fuel costs more than cord wood, it’s not always readily available and the stove requires electricity to operate its continuous feeding system, so a power outage can knock it out of commission.

Wood stoves also can use wood effectively. Newer stoves certified by the Environmental Protection Agency (EPA) can be “extremely efficient, on the order of 70-75 percent, maybe even higher in some cases,’’ says Haase. They produce smoke with particulate emissions vastly reduced from their heavily polluting ancestral cousins, and because they are closed systems like pellet stoves, they generate much more heat than an open fireplace.

Another way to go is to have an installer retrofit your fireplace with an EPA-certified fireplace insert. An insert effectively turns your fireplace into a modified wood-burning stove that’s efficient and far less polluting than the standard fireplace.

The EPA recommends that you hire an expert to install an insert, which can cost between $1000 and $2000. They will seal up the facing of the fireplace, add glass doors between the firebox and the room and add a narrower, more directed escape vent for the smoke within the existing chimney.

That approach should be fairly affordable, but for efficient heating and lowering emissions, it can’t hold a candle to the masonry heater, a type of heating and wood burning system that’s long been used in Europe, but is just now becoming more popular in the United States.

A masonry heater is built to burn wood efficiently and capture the heat and it can do so at 90 percent efficiency, according to the DOE. The heart of the structure is a diminutive, closed firebox where a small amount of wood is burned. The rising warm air travels through a labyrinth of embedded flues or piping so that it can heat the “mass” of brick and stone surrounding the heater box. This captured heat then radiates into the house over time.

Built correctly, a masonry heater can heat a house for 12 to 24 hours on one two-hour “burn” of a few pieces of wood. It doesn’t blow dust around the house like a furnace; it doesn’t pollute the inside air like an open fireplace and its emissions are low, like a pellet stove, because it operates at such high temperatures and achieves a “complete burn.” There’s no creosote build up and no heavy particulate emissions.

“The key word of a masonry heater is heater. It is very energy efficient and very eco-friendly,’’ said Richard Smith, executive director of The Masonry Heater Association of North America (MHA).

Masonry heaters are green on at least two counts, Smith explained, because they’re efficient and have cleaner emissions. “It’s very green. Because of the uncontrolled (fast) combustion in the fireplace you’re burning up all those gases.”

Emissions from masonry heaters are in the same range as for pellet stoves, though they were last tested in 1992. The masonry group hopes that new tighter EPA rules emissions on particulates will prompt new testing that could increase awareness of this type of heating. (To find out more about this issue, start with this EPA FAQ on particulate matter rated 2.5 to 10 micrometers in diameter, which comes from dust, dirt, soot and smoke).

Already some states have experienced fireplace burn bans, as local communities try to keep within federal standards.

“We embrace the EPA looking at the whole emissions issues because our testing has shown we’ll come out with a shining star….We have very little if any emissions going into the air,” Smith said.

Comparing the masonry heater to fireplaces is easy: Masonry heaters are far more efficient, though they do not produce the large blazing hunting party-type fire that some homeowners may desire aesthetically. But comparing the masonry heaters and pellet stoves is trickier. There are many differences – the pellet stove burns continuously, but uses recycled material; the masonry heater fireplace burns quickly, radiates heat for many hours afterward, but uses regular cut wood, a renewable fuel source, but potentially problematic depending on how it’s sourced.

Masonry heaters are custom or semi-custom projects and are more expensive, but they can heat larger areas, even the entire house; whereas a pellet stove heats a room or two, so it serves more as an ancillary heating system.

However, it appears that both these methods produce the most heat per fuel used, have the cleanest emissions and are environmentally defensible if not laudable, especially in our present day in which typical household heating systems are using either natural gas or electricity still largely produced by fossil fuels.

Masonry heaters have not achieved the public attention of other wood-burning devices, Smith says, because they require specialized builders and each must be designed for a specific house and climate. The Masonry Association’s 130 or so members built just about 1,000 of them annually in the United States, and the uniqueness of each model is part of what’s kept the EPA from being able to rate or say much about this type of heating, which depends on so many variables, he said.

A masonry heater is best built with the house in mind because to be effective, the heater must be placed where air circulates around it so it can radiate heat to the largest possible area. (Though the units can be incorporated into an existing house; Frisch has used existing fireplaces as a starting point.) It’s also bulky and requires a large concrete foundation to support its multi-ton weight, though models designed to heat a room or two are smaller in scale.

Such heating has long been used in Scandinavia and other parts of Europe, dating back several hundred years, but failed to become a norm in the U.S. where pioneers built simple, straight chimney fireplaces and fed them with abundant wood, Frisch said. Nothing changed over time as the United States moved onward to rely on heating using oil and gas, also historically inexpensive and plentiful.

“We’re a spoiled society. Gas and oil were cheap. In Europe they’re more practical. They have a history of having them (masonry heaters),’’ said Frisch, a Missouri native who has spent a lifetime building, designing and improving masonry heaters from his longtime home in Washington state . He has built four masonry heaters for himself, two in his house and two in his cabin, including one made of top-notch soapstone, a good heat conductor.

Lately, Frisch, 75, has noticed a renewed interest in masonry heaters, which can incorporate many elegant and popular modern features, such as heated benches and brick ovens.

A custom-built masonry heater can cost $10,000 to upwards of $50,000, but it can cover 60 to 90 percent of a given home’s heating needs, and that appeals to a lot of people, he said. “I think we’re beginning to see North American endorse the masonry concept.”

Paul Richardson, a retired electrician who lives in the Cascades nearing Redding, California, hired Mr. Frisch to install a masonry heater (see picture, right) after exhaustive research on the topic. “I wanted to do something that was economical and good for the environment. This was the best solution,” Richardson said. He’s been quite satisfied with the river stone and slate-top heater, which manages to heat his new 2,300 square foot home.

“It’s not a blaring heat when you get it going, it just stays a constant heat and you only burn two fires every 24 hours. I burn one in the morning and one in the evening and that’s it,” he said.

Richardson and his wife Karen did install extra insulation and a forced air furnace as a back up system — for times when they don’t want to load wood and also to help blow some of the heat to other parts of the house.

But they haven’t had to use the back-up for heat production, despite some icy evenings in the 20s and 30s. In addition to handling the heating, the masonry structure also provides a cuddling spot, the built-in bench, that remains warm throughout the day.

“It’s performing to my expectations,” Richardson said. “In fact, it’s better, I didn’t realize the core of it would stay so warm.”

The warming bench is just “awesome,” says John Richardson (no relation to Paul), another of Frisch’s customers, who recently installed a white tiled masonry heater that heats 1,600 square feet of his house near Twisp, Wash.

“Anyone who puts one of these in should put in a heated bench. It’s the first place people sit down, winter or summer, they sit on the stove….that bench is warm. My wife takes naps on it.”

The Richardsons identify only one downside to a masonry heater, it doesn’t heat up quickly, so it’s best kept on a regular schedule of burning to maintain its warmth.
They fuel their heater with prunings from their apple and pear orchards and also from cedar scraps unsuitable for regular fireplaces. They build two fires a day in winter and each produces only about 15 minutes of smoke, which makes their household heating about as green as it gets.

“It’s (the wood) a renewable resource,” said Richardson, a CPA. “And this carbon (from felled trees), eventually it’s going to go out there, so you might as well get some heat out of it.”

Copyright © 2007 | Distributed by Noofangle Media