heating & ventilation
UNDERSTANDING HEAT MANAGEMENT IN MODERN HEARTH DESIGN With their timeless appeal and dancing flames, fireplaces have the potential to transform a space, regardless of design aesthetic. But that remarkable design dexterity comes with another, sometimes unwelcome, sensory effect: heat.
Fortunately, architects and interior designers can modulate heat in a project. John Shimek, a researchand-development team leader for the Lakeville, Minn.–based fireplace manufacturer Heat & Glo, is an expert in heat science. Over the years, Shimek and his team have made advances in the form and function of gas and electric fireplaces, including developments in heat mitigation.
passive. Both approaches can be engineered to create an abovehearth wall environment that is friendly to heat-sensitive electronics or furnishings: •
Weighing Electric or Gas LED f lames from an elec tric fireplace virtually eliminate heat issues. “Think of the heat from an electric fireplace as roughly equivalent to a small space heater,” Shimek says. Elec tric hear ths play especially well in net-zero energy projects and all-electric communities. The on-demand control of an LED flame is a logical extension of the digital lifestyle, and its non-structural design affords designers and installers wide latitude to confidently create hearth effects anywhere in a residential or commercial structure. For gas-fueled hearth applications, Shimek says heat management takes one of two forms: active and
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Active. This mechanical, fanassisted technology actively draws heat from the fireplace, transferring it through ducts to another room or out of the building. “Removing up to 70% of the heat is comparatively easy,” Shimek advises. Some gas hearths are capable of extracting close to 90% of the heat. “You can put your hand on the glass and it’s just slightly warm to the touch, even after it ’s been operational for an hour,” he says. Passive. This increasingly common approach disperses hea t w i t hou t me chanic al intervention and cost. Instead, passive applies thermodynamic principles to heat transfer through pre-planned ducts that efficiently channel heat above or to the side of the hearth. “Passive is definitely gaining marketplace traction,” Shimek says.
A corollar y to both strategies is right-sizing the hearth to the space. “Most of our appliances, for example, can be throttled back roughly 50% of their maximum BTU output,” Shimek says. “A calculation using room height and square feet can determine the optimum BTUs per cubic feet. That’s why we offer two or three versions of each fireplace model. Each represents the same footprint and design. The only difference is BTU output.” Plan Early Shimek hints more heat control innovation is on the way, uniting “the best of active and passive systems for an even better user experience.” Today, modern hearth technology frees architects and designers from constraints that once limited specification, including the question of unwanted or excessive heat. The key to any heat mitigation strateg y is early engagement with the manufac turer or a fireplace distributor. “Heat is easily managed,” Shimek says. “It’s just a question of anticipating it early in the design.”
