Posted by Karen Duke on 10/5/2019 to Tech
What are gas logs really good for?
Vented gas logs are designed to mimic a wood burning fire in an open fireplace, offering the same realism in both looks and performance; they're best chosen simply for convenience, decoration and ambiance. There's no wood to tote, no fighting to light a fire and you get instant flames at the touch of a button. In most areas it's less expensive to burn gas in your fireplace than to buy firewood.
Vented gas logs are not meant to heat your home - they are designed as a substitute for an open burning wood fire. Vent-free gas logs - or vent-free appliances of any kind - are designed to be used for short periods of time as a supplemental source of heat. Since vent-free appliances (also known as ventless or unvented) actually "vent" into your room, side effects of long-term use can include excessive mold, mildew and poor indoor air quality. Again, not an appliance that's really designed for regular, day-to-day heating use. See this in-depth explanation of unvented gas appliances.
Just like you wouldn't try to heat your house with wood in your open fireplace, gas logs are not meant for this job, either. Gas logs are intended as a means of having a beautiful fire at the touch of a button, and to save you the trouble of toting wood and cleaning up ashes. Vented gas logs use a lot of gas to give you this pleasure at little to no efficiency. If you require or expect a substantial amount of heat, then please consider retrofitting your fireplace with a gas fireplace insert. A gas fireplace insert can heat just like a woodstove but with all the convenience of gas, and use FAR less fuel than gas logs to do the job. (We use a gas insert as a primary source of heat in our own home.)
If you have multiple fireplaces consider gas logs in smaller rooms or rooms that are used less frequently. On a really cold night a gas insert will keep you toasty warm, while gas logs may actually remove heat from the house while the fire burns with the damper open. A gas insert is also an excellent source of emergency backup heat as they can be used without electricity.
Can I put gas logs in my wood stove?
Wood stoves are meant to burn "airtight" or with controlled combustion. Gas appliances actually need excessive amounts of air in order to burn the gas properly. Failure to provide adequate combustion air can result in an explosion. And these explosions have happened when people tried this. Please do not ever install gas logs into a wood stove!
Can I put gas logs in my prefabricated metal fireplace?
If there is a gas line knockout, commonly noted as a dimpled depression in the refractory "firebrick" then you can install gas logs and perhaps even a gas insert. Check manufacturer's instructions for both the fireplace and the gas logs or insert before installation. Never drill holes through the firebox in an unspecified area to run a gas line - use only the knockout access provided. If there's no knockout then don't install gas logs into a prefab fireplace!
Prefabricated wood burning fireplaces were designed to be used to burn wood and with the damper open, which dissipates the heat. Closing the damper and keeping all that continuous heat in the box may cause excessive heat transfer to the walls behind your fireplace, so installing vent-free gas logs into prefab wood burning fireplaces is not generally allowed unless the fireplace has been safety listed for this use.
My chimney sweep says my chimney is unsafe to burn a wood fire in. Can I install gas logs?
Vented gas logs require an operational chimney and fireplace that are suitable for burning wood. Vented gas logs can produce tremendous amounts of soot and fumes and with a faulty chimney they may not exit your home properly. Soot is the least of your worries with a faulty chimney; soot makes a mess but fumes (including carbon monoxide) can kill you. Don't take this lightly! The chimney is very important in the functionality and safety of your gas appliance.
The chimney in my old house was knocked down and only the firebox remains. Can I install vent-free gas logs?
Technically, the answer is no. Even vent-free gas logs require a chimney to be present on an existing fireplace, except in specially made vent-free zero clearance boxes. Occasionally you may find a building inspector who will specify construction of a masonry firebox and allow this, but do so only with his careful supervision; this installation won't be advised by the appliance manufacturer.
My new home was built with a gas fireplace in it, but I like the looks of an open fire. Can I remove the glass?
No. If your system has a fixed glass pane on it then it will definitely malfunction if you remove the glass. Most gas fireplaces with a glass window present are DIRECT VENT models that use a double wall venting system; the outer chamber brings combustion air to the fireplace and fumes exhaust through the inner chamber. Removing the glass would allow the fireplace to draw air from the room and cause a dangerous malfunction.
Can I change the logs that came with it my prefab fireplace?
No. A different set of logs may perform differently and adversely affect the performance of the fireplace and/or the way the burner is designed to operate.
Can I convert my prefabricated gas fireplace to wood?
No. The construction design of the firebox and the heat rating of the chimney are quite different. The chimney requirements are much different! A house fire or explosion can occur if you attempt this conversion.
Can I add a blower grate to my gas logs so that I get more heat?
Not a good idea. Air movement within the firebox chamber may adversely affect the operation of your logs, putting soot and fumes into your house, and most gas log manufacturers specifically state in the installation manual NOT to do this. If you need more heat, consider installing a vented gas insert. These units are specially designed with a glass front to keep heated air from escaping up your chimney; convective chambers and blowers combined with a smaller venting system means most of the gas is used to provide usable heat back into the room.
My fireplace is very small. Are there gas logs that will fit?
Our specialty is finding the right products for very small fireplaces so we do offer some very small gas log sets. However, a very small fireplace - under 30" wide or less than 15" deep - indicates the fireplace was likely a coal burning fireplace. What really looks best for these tiny fireplaces is a gas COAL burner, which uses ceramic coals instead of logs. The burners are much more versatile; they can be installed into fireplaces as small as 6" deep and 12" wide. They're also more historically appropriate since coal fireplaces are only found in old houses.