A sweeps view of Gas Logs

There are a few other professionals out there speaking their mind about the gas invasion of the purehearted woodman's land. The following is a clip from CPM... Chimney Professionals Magazine....

From: [email protected] (Bill Kline) Subject: Re: gas

I have written a brochure titled "The Case Against Gas Logs" which I hand out to people, and I copied from April 95 SNEWS an article reviewing Dave Pomeroy's view of unvented logs on one side, and my letter to the editor in response to that article on the other side. Between the two, I have been able to persuade several people to stay with wood.

The Case Against Gas Logs


For the last year or two, the hottest thing on the market for your fireplace has been gas logs. Gas log manufacturers have been having a heyday, with claims of convenience, economy, and cleanliness topping the ad strategy. And homeowners have been flocking to dealers' showrooms and taking some home. I'd like to help sort out some of the facts from the fiction about gas logs, and suggest some better options for your consideration.

One claim that is typical is "Deluxe"(brand name) Gas Logs burn clean eliminating pollutants produced from wood fires, and eliminates unnecessary chimney cleaning. The facts are that the pollution produced by gas logs may be more serious than that of wood fires. Most of the pollution from wood fires is temporary it settles out, or the rain washes it out of the air. The pollution from gas logs is mostly carbon dioxide (CO2), which seems harmless enough. But when you consider that our atmosphere has an estimated 9 billion tons too much CO2 in it (ever hear of the greenhouse effect?), then you can begin to be concerned about excess CO2 pollution. The other pollutants include trace amounts of Sulfur and Chlorine and whatever else is in the air in your house. And the part about unnecessary chimney cleanings? No ethical chimney sweep will sell you an unnecessary chimney cleaning. But no competent chimney sweep will tell you that if you have gas logs, your chimney won't ever need cleaning. If your logs have a realistic yellow flame as a result of a pan burner, they burn dirty, and make a nasty, sooty mess of your chimney (and produce lots of Carbon MONoxide (CO)). And remember those trace amounts of Sulfur and Chlorine? They condense in the soot, and the summer moisture mixes with them to form acids in your chimney which can eat away your mortar and flue tiles.

So, one main objection to gas logs is their significant contribution of CO2 to the already overloaded atmosphere. The EPA has recently stated that our best hope of reversing the greenhouse effect is to convert 15 million old wood stoves to new EPA Certified clean burning stoves, and switch another 15 million homes from heating with gas and oil to new tech wood stoves, and then plant the trees to fuel 30 million wood stoves every year. This would reduce CO2 by 1/2 billion tons annually.

Another ad claim is, (brand name) gas logs eliminate the high cost of wood. This is true, to be sure. But what they didn't mention was the higher cost of gas. A typical leading brand's 24 inch gas log set consumes 90,000 BTUs per hour. (A 2,000 sq. ft. home in the Greenville, SC area can be heated by a 90,000 BTU gas furnace running a few minutes each hour!) The 18 inch set burns 75,000 BTU/H. Some of the "high efficiency" units are as low as 45,000 BTU/H. Some of these have heat extractors that blow a little heat out. But basically all you get for your gas money is a realistic fire. According to a study by the University of Wyoming, as the temperature outside approaches 40¡, the efficiency of an open fireplace approaches 0%. As the temperature drops below 40¡, the efficiency drops below 0%. While you may feel warm in the room with the fire because of radiant heat, the fireplace is taking more heat up the chimney than it produces. The main thing your gas logs heat is the greenhouse effect. This constitutes a tragic waste of a limited natural resource for no benefit except the joy of watching it burn. And one more thing, included with gas logs is a little clamp that the law requires be installed on your damper to prevent it from closing all the way. So, not only is it wasting your fuel dollars when the logs are burning, but also when they are NOT burning!

If you want the convenience and aesthetics of gas logs, but don't want to waste all that fuel, consider one of the new vented gas log inserts now on the market. Most of these burn a maximum of 20,000 to 30,000 BTU/H, and are from 75 to 80% efficient. So you can have your nice gas fire, burn a fraction of the gas, and contribute significantly to heating your house. The initial investment is more than gas logs, but the gas bills are forever much less, as is the resulting CO2 and CO pollution.

There are some unvented gas appliances on the market. Some are very efficient, claiming efficiencies as high as 99%. However, there are some downsides to unvented gas appliances. The main thing is that "unvented" is a misnomer, they are just vented into your living space instead of directly to the outside. This requires that you always keep a window open in the room with the heater. The safety instructions with each such unit generally call for 1 sq. in. window opening per 1,000 BTU input (so much for 99% efficiency!) Because burning gas produces large quantities of water vapor, unvented gas heaters also tend to darken ceilings, curtains, etc. with mildew. The Oxygen Depletion Sensor shuts the burner off before it starts producing CO, but what becomes of the 1%? What other pollutants are being dumped into your living space?

Unvented gas appliances are not recommended for people over 65 years old, or people with respiratory problems. If they are not good for those people, what makes them desirable for younger, healthier people? With all the bad news we've been hearing about indoor air quality and Sick Building Syndrome, do we really want to add gas combustion by-products to the mix? I suspect that 15 or 20 years from now we'll learn that people who breathe that stuff will have a higher incidence of some serious disease than people who don't.

My advice: stay away from the unvented gas appliances unless you want to keep a window open when burning, and repaint your ceilings every spring. And stay away from them if anyone in your house tends to have respiratory difficulties. And stay away from them if you don't want to be a medical science guinea pig!

In closing, let me suggest you consider this question: Perhaps our generation of Americans is affluent enough that we can afford to waste gas, a limited fossil fuel. But can our grandchildren afford for us to waste it??
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