Installing a gas fireplace

Startup Decisions

How the burners ignite when you flick the switch affects efficiency, but Fuegler suggests this might be one decision, depending on your situation, where safety might outweigh efficiency. A traditional pilot is reliable in a blackout, but burns constantly-not very energy efficient. A two-stage pilot is better. It burns at a very low level most of the time, and flares up when you turn the fireplace insert on. When you’re not using the insert regularly, extinguish the pilot to save gas.

Electronic ignition systems don’t burn any gas, so they are the most energy efficient, but require a battery backup to ignite if the power is out.

Comfort Levels

Without any heat control, a fireplace is just a decorative blast furnace. Heat output can be controlled in three ways: by cycling the flames on and off, by adjusting the flame height, and by adjusting the fan speed. In some models, these adjustments are manual. There’s a switch for a low or high flame, or there’s a switch to control the fan speed. Other models come with a thermostat that adjusts automatically as the room temperature changes.

The range between minimum and maximum gas inputs (see BTUs In and Out, right) is a good indication of how much heat control an insert offers. If you plan to use your fireplace year-round, a fireplace that can be turned way down is a useful feature.

Steve Haagmans has a final tip on getting more comfort out of your fireplace, something he says people often forget: “Read the instructions, or get the installer to show you how to use your insert. Your fireplace can probably do a lot more than you realize.”

BTUs In and Out

On the backs of those glossy insert brochures, you’ll find numbers that will tell you how well each fireplace works as a room heater.

First, mind your BTUs. A BTU (British thermal unit) is a measure of the heat needed to raise the temperature of one pound of water by one degree Fahrenheit. For example, lighting a wood match generates about one BTU. The amount of gas a fireplace consumes can also be expressed in BTUs per hour. (With a flame that can be adjusted, you’ll see a range of numbers-from minimum to maximum input.)

Even the most efficient inserts lose some heat or unburnt gas out the vent. How much? Look for efficiency ratings. An efficiency of 76 per cent, for example, means the insert turns 76 per cent of the gas into heat in the room.

Exactly how this efficiency is tested is an important “apples-to-apples” consideration if you’re comparing brands. “Steady-state” means efficiency when the fireplace is burning at a constant rate. Since you’re not likely to leave your fireplace on 24 hours a day, fireplaces are also tested for AFUE, or Annual Fuel Utilization Efficiency, which measures the efficiency with all the usual stopping and starting, heating up and cooling down. Steady-state ratings can be significantly higher than AFUE numbers, so be sure you know what you’re looking at.

The third measure is the newer Annual Fireplace Efficiency (AFE) rating, which uses a made-in-Canada fireplace test, similar to AFUE. Ask the fireplace retailer for these numbers, as they haven’t made it into many brochures yet.