See-through fireplaces boost design options

Versatile indoor/outdoor propane fireplaces capitalize on the outdoor living trend while sealing out fluctuating weather conditions.

By Sharon O'Malley

Homeowners who enjoy the flickering of propane flames on the outdoor patio as much as they do by the family room hearth can achieve both with just one fireplace.

See-through propane fireplaces installed on a home's exterior wall have two fronts: one that looks into an indoor room and another that faces the great outdoors.

"People absolutely love them," notes Harold Wagner, an installer and national sales manager of Internet retailer He worked with one homeowner who had hers installed mid-wall in the kitchen, like a window, so she could watch her children playing in the yard while she prepared dinner.

First to the market with the indoor/outdoor fireplace about a decade ago was Heat & Glo, whose revamped Twilight model still accounts for a small percentage of the manufacturer's sales. Becky Scribner, director of brand marketing for Hearth and Home Technologies, which makes Heat & Glo and Heatilator products, estimates that less than 1 percent of all fireplace sales industrywide are of indoor/outdoor models.

Heat & Glo's Twilight II indoor/outdoor fireplace, which operates on propane or natural gas, has a 36-inch viewing area on each side and requires no venting. The manufacturer says the fireplace is firmly sealed to the exterior side of the wall to help prevent condensation and stop cold air from leaking into the home.
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The Montebello ST is a double-sided, direct-vent fireplace by Innovative Hearth Products. It features a 40-inch glass panel on both its indoor and outdoor faces. With a high-definition, split-oak log set and a burner that provides 60,000 BTU per hour, the propane- or natural gas-fueled unit comes with the manufacturer's Total Comfort Control system, which features a full-function remote that controls flame, temperature and fan speed.
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But sales could increase. All of the major fireplace manufacturers have recently introduced their own versions of the two-sided fireplace, which retails for upwards of $5,000 and can be installed during construction of new homes or retrofit in existing homes.

Unlike an indoor-only, see-though fireplace, which has two fixed glass doors — one each in two adjoining, temperature-controlled rooms — the indoor/outdoor version is exposed on one side to fluctuating weather, which could include heavy rain, extreme heat or cold, or high winds. Innovative Hearth Products (formerly Lennox Hearth Products) addressed those fluctuating conditions with an additional layer of ceramic glass — behind a sturdy tempered-glass panel — that is gasketed and tested for water and wind intrusion on the outdoor side of its Montebello fireplace. Homeowners have the option to tint the glass for privacy.

Scribner says newer versions of Heat & Glo's Twilight fireplace are firmly sealed to the exterior building envelope to prevent condensation and stop cold air from leaking into the home. The Twilight model is also rated for extreme weather conditions and features a ceramic glass outer door and tempered glass on the interior door.

Most manufacturers have designed their indoor/outdoor models as direct vent fireplaces that use outdoor air for combustion and expel the exhaust through a center pipe that opens through a wall or chimney. Heat & Glo's model, however, is vented directly to the outdoors with no piping; the exhaust is expelled to the outdoors through a small hood at the top of the viewable area of the fireplace. Scribner says this feature makes the unit easier to install.

Wagner says most of the luxury fireplaces he sells go into high-end homes in California and New York, but manufacturers note that they have sold to owners of single-family homes, town homes, and office buildings all over the United States and Canada.

Don Kaufman, Innovative Hearth Products' product manager for fireplaces, says he expected the indoor/outdoor fireplace to sell best in the Southwest, where homeowners enjoy warm weather — and can use their patios and outdoor kitchens — nearly year-round. But because the fireplace can be used indoors or out, even homeowners in cold climates are making the investment.

"In smaller footprints, the outside space becomes a living space throughout much of the year, so versatility in the use of that space becomes important. Here's a device that lets you install a single fireplace that you can enjoy in two aspects."

Some builders and remodelers are having installers create decorative surrounds to dress up the stainless steel frame that most manufacturers supply with the firebox. Some homeowners also are remodeling their indoor rooms to accommodate the fireplace's chase. Because the fireplaces typically measure around 16 inches deep, Wagner says several of his clients have requested that he conceal the "bump" into the interior room by building a mantel over the fireplace and deep bookcases around it.

Kaufman predicts the market for indoor/outdoor fireplaces will grow as more homeowners opt for smaller houses.

"In smaller footprints, the outside space becomes a living space throughout much of the year," he says, "so versatility in the use of that space becomes important. Here's a device that lets you install a single fireplace that you can enjoy in two aspects."

And as more homeowners build outdoor kitchens, he notes, more are adding outdoor fireplaces of all kinds.

Scribner agrees. "The beautiful thing about a fireplace like this is it allows [the homeowner] to take advantage of the outdoor living trend while it provides the fireplace for the indoors."

To learn more about propane fireplaces and fire features, check out these articles from the Propane Energy Update:

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