Wood Burning Insert Installaiton - Chicago IL - Aelite Chimney SpecialtiesThe new EPA-certified wood-burning fireplace inserts can convert your old masonry fireplace into a clean burning, energy-efficient, and effective fireplace. However, Aelite Chimney Specialties would like to stress how important it is for these inserts to be professionally installed. Some people believe they can install their wood-burning fireplace inserts themselves; however, many times we have had to go and properly reinstall inserts because of problems that occur from do-it-yourself installations. An insert is basically a wood-burning stove designed to fit into an existing fireplace, so it seems simple to install on your own. The problem lies with the size of your chimney flue as it is typically too large for the fireplace insert, and this can cause hazardous problems. We would like to share with you some information from The Wood Heat Organization to explain these problems and why it is so important for your wood-burning fireplace insert to be professionally installed.


In the early 1980’s, when fireplace inserts first hit the market, they quickly received a bad reputation for not being very efficient and being unsafe and expensive to maintain. People were just putting these in their old fireplaces with no connection to the chimney. The exhaust gases would exit through the flue collar and eventually work their way out through the chimney. To solve this problem, a short length of stainless steel liner, or a “direct connect,” was added to go directly through the chimney, but there was no connection to the base of the chimney. These inserts were difficult to light, smoky to use, and difficult to clean as the insert had to be removed to clean the chimney. An outbreak of chimney fires caused national fire safety organizations to investigate this issue.


The main problem lies with the chimney’s flue being too large for the wood-burning fireplace insert. An insert is typically designed to vent through a six-inch (or 28 square inches) exhaust. Most fireplaces have a 121 square inch flue, which is four times larger than what an insert is designed for venting. This sizing difference leads to a couple of problems:

1. differences in temperatures

When the flue is disproportionately larger than the insert, your chimney stays colder than it would with a properly sized flue. When your chimney is cold, the hot smoke and gases condense and form creosote, a hazardous and combustible residue, which sticks to the walls of your chimney. If you use your wood-burning fireplace insert regularly, this can lead to a possible chimney fire in about five weeks.

2. smoke residence time

The amount of time smoke remains in the flue, smoke residence time needs to be as short as possible. The only way to accomplish short smoke residence time is by using a correctly sized and insulated flue for your insert.


When Aelite Chimney Specialties installs wood-burning fireplace inserts, we also install a stainless steel chimney liner that properly fits the insert. This will solve the temperature differential and smoke residence time problems and make your insert safe to use without a risk of major creosote buildups and a possible chimney fire.

Have more questions about wood-burning fireplace inserts? Contact  Aelite Chimney Specialties to ask us anything you would like to know.