As electric fireplaces don’t produce any real flames, they can be considered to be 100% efficient.

All of the electricity used by an electric fireplace goes to producing either the flames and/or the heat (in which in-built space heaters or infrared heaters are used). They also don’t need venting because there are no wasteful by-products produced.

Gas fireplaces are typically less efficient compared to electric fireplaces because much of the heat can be lost outside as a result of the venting requirements, but again this can differ depending on the type of gas fireplace.

Gas logs and gas inserts for use in existing masonry fireplaces are typically the least efficient.

Direct vent gas fireplaces can be pretty good in terms of efficiency but ventless gas fireplaces can be very efficient.

We’ve covered electric fireplace efficiency and gas fireplace efficiency in more detail in their respective articles.

As a result, electric fireplaces don’t release any pollutants into the atmosphere and so can be considered to be extremely clean burning, while gas fireplace can be good or bad in terms of pollution depending on the type.

Gas fireplaces will still be far less polluting than burning wet firewood, however.