The case of the foggy fireplace glass

What causes the glass on my gas fireplace to get foggy?

If you are looking for a gas fireplace, you have some choices.  If you have a wood burning fireplace, you can install a gas insert. Regular gas fireplaces are what you’d find in new construction.

There are gas also gas logs, but they have some major problems. They cost a lot, because they draw so much conditioned air into and up the chimney. Gas logs can actually be quite dangerous, because of the risk of CO poisoning.

You can learn more by clicking here.

The fog is created by the moisture in the exhaust, condensing on the cool glass. The fog goes away when the window warms up, so you only see it when you first turn on the fireplace, and only for a while. Over time, however, the foggy appearance doesn’t go away. Why? The foggy look is no longer condensation, but etched glass that looks like condensation.

The process of burning natural gas produces moisture that has a high level of sulfuric acid. That acid etches the glass, making the foggy appearance permanent.

The glass can (probably) be polished.

You can learn how to do it yourself . Look up the model number and get a manual from the manufacture. A lot depends on how badly the acid has damaged the glass. Ace hardware makes a glass polish that seems to work pretty well.

If the glass is too badly etched, it will need to be replaced, at a cost of $200 to $400.