What kind of gas fireplace should you install in your home? Gas fireplaces can be direct vent, natural vent, or unvented/ventless/vent-free

Direct Vent

Direct vent fireplaces have sealed combustion systems that protect indoor air quality by drawing outside air for the fire (all fire needs oxygen, this “combustion air” is drawn from the outside) and expelling 100 percent of combustion exhaust and by-products outside the home. In Massachusetts, in a bedroom, the ONLY gas appliances permitted are direct-vent gas fireplaces, stoves, or inserts. Direct vent appliances have sealed glass in thr front.

Natural Vent

Natural vent gas stoves and fireplaces work much like traditional wood fireplaces. They draw the needed oxygen from the air in the home, and draft the exhaust up the chimney / vent pipe. Similarly, they are subject to the same challenges as wood-burning fireplaces. When the wind blows, or the home’s air flow challenges the stove’s ability to pull in the oxygen it needs, the stove always loses and the home experiences backdrafts/sooting/flame outages. Given the ability to prevent such issues with a direct vent appliance, these “natural vent” appliances are rapidly becoming obsolete. Natural vent appliances usually have sealed glass in the front.

Unvented / Ventless / Vent-Free / Room-Vented

In contrast, unvented (a.k.a. vent-free, ventless, or room-vented) fireplaces lack sealed combustion or venting systems. Instead, ventless appliances draw indoor air and oxygen for the fire. Then, they expel exhaust and byproducts, like carbon monoxide, nitrogen dioxide and moisture, into the home. Although these products are safe, the moisture and odors they emit can be irritants to people with respiratory sensitivities, allergies, or asthma. In addition, because of the heat they generate, ventless gas logs have tall mantel clearance requirements that often disqualify them as options for installation. Under pressure from gas appliance manufacturers, Massachusetts was one of the last states to make ventless products legal. So, while finally legal in Massachusetts, we at Enchanted Fireside remain reluctant to recommend ventless appliances. Why? Because so many owners of vent-free appliances have come to us to replace them with direct-vent appliances. They seek to replace their “vent-free” appliances because they cannot run them without irritation, annoying smells, or high moisture condensation issues that come from having the combustion byproducts exhausting into their home. Basically, they are just not “warm & happy.” In fact, most of the manufacturers carried by Enchanted Fireside have chosen not to manufacture any unvented fireplace products. In the industry, we are seeing the remaining manufacturers gradually phasing these products out. Vent-free/ventless appliances will have a screen in the front, not glass.