"Art" wrote in message
...
If you want efficiency buy zero clearance logs with ceramic glass front.
Some are as efficient as a furnace.

As "efficient" as a very inefficient furnace.

Even the best gas fireplaces (those that preheat outside combustion air with
the exhaust) are hardly models of efficiency. They are first and foremost
designed to "look good."

Ventless gas inserts are quite safe. In some respects they are safer than
vented models which do produce some CO. They add a VERY small amount of
moisture to your home (the equivalent of a few quarts of water). Unless
your home is VERY tight, the moisture will be a benefit.

Some folks are "sensitive" to the combustion products of ventless units. We
have a ventless unit. The flue has been sealed off and 100% of the heat
goes into the room. We are quite happy with it.

When the electric service goes out we use a portable LPG heater (ventless
type) to keep the family room comfortable.

The ventless units burn with grossly excess O2 and thus don't produce any
CO. They might produce very small amound of nitrogen oxides.

For "belt and suspenders" purposes you should have a CO detector (or 2 or 3)
if you bus gas (natural or LPG) in your home.