What is the efficiency rating of a gas insert versus my open Calgary fireplace?

A gas insert will increase your fireplace efficiency from roughly 10-15% to 70-85% — transforming your existing masonry fireplace from an energy-wasting decorative feature into a genuine heating appliance that can meaningfully warm your Calgary home during our brutal winters.

Your current open masonry fireplace operates at dismal efficiency because most of the heat goes straight up the chimney along with the heated air from your home. In Calgary's extreme cold, an open fireplace actually creates a net heat loss — it pulls warm air from your living space and sends it outside while drawing cold outdoor air into your home through gaps and cracks. During a -25°C January cold snap, running an open fireplace can actually make your furnace work harder.

A gas insert completely changes this equation. Modern gas inserts use sealed combustion with a glass front, so they don't pull heated air from your room. Instead, they draw combustion air from outside through a flexible liner system installed in your existing chimney. The sealed firebox captures and radiates heat into your living space rather than sending it up the flue. A quality gas insert producing 25,000-35,000 BTU can effectively heat 800-1,200 square feet in a well-insulated Calgary home — enough to reduce your furnace load and provide comfortable zone heating in your main living areas.

The efficiency difference becomes especially meaningful during Calgary's six-month heating season. At current ATCO Gas rates of approximately $3.50-$5.00 per GJ, running a gas insert costs roughly $0.75-$1.25 per hour of operation. While your open fireplace burns the same amount of gas or uses seasoned firewood, virtually none of that energy heats your home effectively. The gas insert captures 70-85% of the combustion energy as usable heat.

Installation involves sliding the insert into your existing firebox and connecting it to a flexible aluminum or stainless steel liner that runs up your existing chimney. This requires a gas permit from the City of Calgary, gas line connection by a licensed gas fitter, and Safety Codes Officer inspection. Total project cost typically runs $2,500-$5,500 including the insert, liner system, gas line work, and installation labor.

Before installing any insert, have your chimney inspected for structural integrity, proper draft, and liner condition. Calgary's freeze-thaw cycles and chinook temperature swings can crack chimney crowns and deteriorate mortar joints, which must be repaired before liner installation.

The efficiency upgrade pays for itself through reduced heating costs and transforms your fireplace from a decorative liability into a functional heating asset that provides real value during Calgary's long, cold winters.

Need help finding a fireplace installer? Calgary Fireplaces can match you with local contractors who specialize in gas insert installations and chimney liner systems.