Thread: Gas Log Set

A gas log set recently installed in an older masonry fireplace. There is no clip on the damper to hold it partially open. Owner tells me because the log set is less than 30,000 BTU, a clip is not needed. He also tells me that the damper doesn't have to be opened at all with a unit of this size.
I could not find any info on manufacturer on unit.

I doubt this is true, but has anyone heard of this?

Could be a "ventless" log set.

But those would not have doors on them ... would they? Otherwise, how do they get combustion air and vent to the interior?

Neal,
I’m afraid that it might be too late for the Owner. The carbon monoxide has already caused irreversible damage. He is delirious and incoherent. It is very strange that those exposed to C.O. seam to always be in denial. It must be the neurological area that is affected first.

All decorative gas appliances (gas logs) require a safety clamp to block the damper in a position that safely conveys all gasses to the exterior. This would be a minimum of 15 square inches (1 square inch for every 2000 BTUs). However, based on personal experience, I would recommend that the damper be placed in the full open position for safety. This requirement is to protect us when we fail to open the damper during operation. We know that the damper is closed when we burn wood (the house fills with smoke) however, this is not he case with a gas appliance. That’s why they call it the “silent killer”.

related question..... is the flue being held open strictly for exhaust gas or is it also in case there is a gas leak? Is gas heavier than air or lighter?

Originally Posted by Matt Fellman

Is gas heavier than air or lighter?

It depends on the kind of gas. Natural gas is lighter than air. Propane is heavier than air.

Originally Posted by Matt Fellman

related question..... is the flue being held open strictly for exhaust gas ... ?

Matt,

Strictly for combustion by products. Which is why some do not have the vent and are "ventless" gas log sets. They "vent" to the interior of the home, using up its oxygen.

The main difference between the unvented space gas heaters of years gone by (the ones which were outlawed because they killed people) and the newer "ventless: gas log sets is that there is a metal warning tag on the ventless ones stating 'YOU CAN DIE' if blah-blah-blah.

In other words, the main difference is that the attorneys for the manufacturers of the newer ventless ones beat the dead people to the punch by saying 'don't sue the manufacturer, they said you could die if you used this without blah-blah-blah, and you did'.

If you cannot locate a rating plate on a gas appliance you must treat it as an unlisted appliance. Since listed appliances are now required, I would recommend it be removed.

The issue of damper opening is addressed in the mfrs. listed instructions and is based on the input BTU rating. The State of Mass requires the damper be removed or welded wide open, which exceeds the requiremets of any of the model building codes.

That homeowner sounds like he used to own a stove shop. Many operate on heresay instead of facts. Tell him to produce the rating plate and manual if he's such an expert.

Originally Posted by neal lewis

A gas log set recently installed in an older masonry fireplace. There is no clip on the damper to hold it partially open. Owner tells me because the log set is less than 30,000 BTU, a clip is not needed. He also tells me that the damper doesn't have to be opened at all with a unit of this size.
I could not find any info on manufacturer on unit.

I doubt this is true, but has anyone heard of this?

I've been in the natural gas business for 34 years and I've never heard of this...Has he has it tested for CO?

I have a ventless gas insert and have been using it for about ten years, all I ever do is crack the dampeer a little and ive never the co2 alert go off in my house , so i guess its ok. Do they make some kind of stop that can be attached to the damper , thanks for any info.

Originally Posted by daniel nantell

I have a ventless gas insert and have been using it for about ten years, all I ever do is crack the dampeer a little and ive never the co2 alert go off in my house , so i guess its ok. Do they make some kind of stop that can be attached to the damper , thanks for any info.

It's not CO2, it is CO. During our use of oxygen, our bodies actually create CO2 and it is the build up of this in our lungs that cause us to breath. While CO2 in an abundance can cause issues and even death, it takes a large amount. CO on the other hand is easier to absorb into our blood and will actually be absorbed in the presence of oxygen instead of the oxygen. It is hazardous in as little as 50ppm (over an 8 hour period)

I have seen the small c-clamps used to hang conduit from beams installed on the damper.