Ventless? Don't Even Think About It

What we've been saying the last few weeks is: energy and indoor air quality are equally important to your fiscal and physical health. If your house is not "net zero" for energy, if your energy budget is a large chunk of your income, if you'd like to join in the fun and enjoy some alternative energy, you're looking for low-cost ways to play.

Enter the ventless gas or gel-fuel fireplace. Costing hundreds not thousands of dollars, able to be attached to a wall or set up in the middle of a room, and capable of burning liquid petroleum gas as well as natural (city) gas, the ventless fireplace sells itself as a near-advent level blessing for us regular folks who want to go green.

Hold on, though. The fuel, whether natural gas, LP or fuel gel, is the same petroleum-based fuel you're burning in your basement boiler or furnace. Costs the same, burns at the same efficiency with the same gross environmental impact (carbon footprint, CO2 emissions, Sulfur derivatives, stuff like that). The good news is that the entire combustion process takes place in your living space, so no heat is lost up the chimney. Very efficient. The bad news is that the entire combustion process takes place in your living space and you breathe everything the fireplace emits. CO2, CO, sulfur derivatives, carbon particles, all that stuff.

And is that bad? Some experts say no. The best manufacturers include, as a safety device, an "oxygen depletion sensor" which shuts down the fireplace if the oxygen in the room drops to dangerous levels. Dangerous levels? DANGEROUS LEVELS? Advertised combustion efficiency varies from 92% to 99%. The rest of the unburned or partially burned fuel goes into your lungs (carbon, sulfur, carbon monoxide, etc.). Or on the floor, or on the leaves of your houseplants, or on your furniture.

Do you cook with natural gas or LP? Well, one argument maintains that many people use gas ranges and ovens and come to no harm. Fair enough. But even cooking with gas releases the same combustion gases into your home. And, building codes require that vent hoods be installed over cooking devices. For a reason. Cooking vapors and combustion by-products are harmful to indoor air quality and should be vented outdoors.

Vented gas fireplaces don't always require a conventional chimney. They cost 25% or so more than unvented fireplaces, require expert installation, and require a penetration through an outside wall for the vent. They operate at efficiencies of 75% or so, and generate both convective and radiant heat for the comfort of the living space. That's about the same efficiency as the central heating unit in the basement. So, no impressive savings, just a lovely flame effect and a snug feeling from the radiant warmth.

If you're impervious to combustion fumes, you're a better man(woman) than I. If you want to install a low cost alternative heating source in your home, the unvented gas fireplace will do. But please, don't neglect to purchase the oxygen-depletion safety feature. And crack a window, and don't go to bed and leave the fireplace burning. Take care of yourself. I can't afford to lose loyal readers.