Improving your fireplace’s energy efficiency

1. Chimney sweeping

Your chimney needs an annual cleaning. An experienced chimney sweep (ideally, a member of the Association des professionnels du chauffage, or APC) should also alert you to any irregularities and, if need be, offer to provide a more thorough visual inspection.

That inspection, of course, must be done after a thorough cleaning, to ensure a clear view. If a design problem is detected or parts of the chimney are excessively deteriorated, the situation will need to be corrected in short order.

Don’t rely on a verbal opinion. A good chimney sweep should provide you with a written inspection report—ideally accompanied by supporting photos or a video.

Other times when a full chimney inspection is recommended:

• The chimney was last swept quite some time ago;

• You’ve noticed an issue with fireplace combustion or drafting, or deterioration of the chimney;

• You’ve recently bought your house, or are planning to sell it;

• The bylaw governing heating appliances in your area has been amended;

• Changes have been made to the fireplace setup, or you are planning such changes (e.g., installation of a fireplace insert).

2. Repairs to damaged masonry

A broken chimney crown. Missing, cracked or loose bricks. An unstable or inadequate chimney cap. Insufficient clearance above the roof. All of these are factors preventing optimum energy efficiency—not to mention that they can be outright fire hazards in certain cases. Fortunately, a competent specialist can correct these problems and ensure that all aspects of your fireplace and chimney are compliant with National Building Code requirements.

3. Insertion of an insulating chimney liner

This operation consists of installing a stainless steel “sleeve” inside an existing chimney; e.g., to compensate for eroded clay flue blocks that are no longer airtight. The liner is designed to resist high temperatures and may be rigid or flexible.

Depending on the chimney configuration, one or other type of liner, or a combination of the two, will be installed. The type and diameter of liner must be determined by a certified technician who is a member of the APC. Whether of the rigid or “flex” type, the liner must meet the Underwriters’ Laboratories of Canada ULC-S635 standard.

When the work is complete, you should receive a certificate of compliance to meet insurance as well as municipal requirements. Many liners come with a lifetime parts and labour warranty.

4. Converting a traditional fireplace to a fireplace insert

A fireplace can also be made more energy-efficient by mounting a prefabricated metal unit called a fireplace insert into the existing hearth. Certain installation precautions must be taken, and the unit must meet the requirements of the ULC-S628 standard.

Fireplace inserts currently on the market include models that emit a maximum of 2.5 g of fine particles per hour (certified by the United States Environmental Protection Agency, or EPA). This complies with the strictest requirements so far enacted in North America: those of the Montreal standard, slated to take effect in October 2018. By installing a fireplace insert as well as a liner, owners of stone chimneys in Montreal can continue to regularly heat their homes using wood.

It should be noted that this emission standard is even lower than the current Quebec government limit of 4.5 g/h (EPA-certified) for acquisition of any new wood-burning residential heating appliance. To learn more, read our article Choosing the right fuel wood.

One final note: if the improvements you make to your fireplace change how you use it (e.g., you burn four cords of wood instead of one), notify your home-insurance provider. They will add this information to your file and, if necessary, adjust your policy.