Pros & Cons of a Mountain Hearth Ventless Gas Fireplace

Vents

• Most fireplaces need a system of pipes, ducts or a chimney through which they can draw in fresh air to fuel combustion and exhaust the byproducts of combustion. Installed pipes and vents add to the expense of installing a fireplace or stove and require cutting through the wall or roof, making vented systems impractical for rental properties or apartments. Mountain Hearth ventless gas fireplaces don't need venting or ductwork, so you can use them almost anywhere.

Moisture

• Combustion produces water vapor. In a vented gas fireplace, this water vapor goes up the chimney or out the vent pipe. A ventless gas fireplace, such as those produced by Mountain Hearth, releases this moisture into the room. If you live in a dry climate, the extra humidity in the house in the winter is a plus, adding to your comfort and reducing static electricity. However, in more humid climates, the humidity produced by a ventless fireplace can lead to wet windows and walls. To cut down on this problem, open a window slightly to allow the excess moisture to escape.

Efficiency

• White Mountain Hearth claims its ventless gas fireplaces operate at 99.9-percent efficiency, producing few pollutants and wasting very little energy. Because you can use these fireplaces in any room of your home, you can use them for zone heating, or heating only the room where the fireplace is located and turning down the heat in other rooms you aren't using, which can save you money since you don't have to keep your whole house warm to enjoy the one room where you spend most of your time.

Safety

• White Mountain Hearth ventless fireplaces include an oxygen depletion sensor to detect low levels of oxygen from the room. This can occur if the stove is drawing too much air from a tightly sealed room or if the stove releases carbon monoxide gas into the room. The Hearth, Patio & Barbecue Association recommends you have a professional inspect and service your stove every two years. In addition, use unvented gas fireplaces only as a source of supplemental heat, not your main heating source, and do not operate them for more than two hours at a time. A study published in the October 2010 issue of "Indoor Air" looked at indoor air quality in 30 homes where ventless gas fireplaces were used over a three- to four-day period. Researchers found that carbon monoxide levels in 20 percent of the homes exceeded recommended safe levels. Eighty percent of the homes also had levels of the pollutant nitrogen dioxide that exceeded World Health Organization standards.