A boiler is a type of central heating unit that uses hot water or steam to heat a space instead of forced air. Depending on your existing heat system and your climate, a boiler may be an effective and economical method of heating your home. Like all central heating systems, a boiler represents a substantial investment. To maximise your investment, consider factors such as sizing, total cost and energy efficiency to find the best boiler to meet your needs.
Determine the correct size for your boiler. According to Air Conditioning, Heating and Refrigeration News, the old "rule-of-thumb" sizes don't apply anymore. For example, boiler sizing used to be based on the square footage of the home, which often resulted in boilers being grossly oversized. Today, boilers are sized according to the total heat loss in the home. Heat loss calculations are based on insulation levels, climate and home design. Refer to the Resources section for a free online sizing calculator.
Compare efficiency levels. Boiler efficiency is listed as the annual fuel utilisation efficiency (AFUE). AFUE represents the percentage of energy consumed that is converted to heat, with higher values associated with more efficient boilers. The American Council for an Energy Efficient Economy recommends choosing a boiler with an AFUE of 85 per cent or higher. Those in very cold climates may benefit from even higher efficiency levels.
Consider the fuel source for each unit. A boiler can be powered using electricity, oil or gas. The cost to operate each of these units can vary widely, depending on the price of these energy sources in a specific region. To decide on the most economical fuel source, obtain unit pricing from energy suppliers in your area, then choose a boiler that runs at the lowest possible cost.
Think about whether you need a boiler for heating only or a combination unit that can also provide hot water. Combination units can replace a water heater entirely and may be more cost effective, depending on energy prices in your area.
Check for tax rebates and other incentives. Many state and federal programs offer financial incentives for taxpayers who invest in energy-efficient technologies. While the most efficient boilers may cost more than standard units, the added cost might be offset by credits or rebates. Refer to the energy efficiency incentive database in Resources to find information relevant to your location.
Evaluate the total cost of each unit, including materials and equipment, labour, installation, service and any other applicable expenses. Once you've determined your total cost, divide this by the capacity of the boiler in BTUs. This will give you a cost per unit of heat provided, which can help you make an "apples-to-apples" comparison.