High Efficiency Natural Gas Furnaces

If your furnace is more than 15 years old, it is probably a standard-efficiency furnace that has an Annual Fuel Utilization Efficiency (AFUE) of about 60 per cent. An AFUE rating of 60 per cent, means that 40 per cent of energy used will be lost up your chimney. AFUE ratings for mid-efficiency furnaces range from 78 to 82 per cent and a high efficiency furnace is 90 per cent and above.

A high efficiency natural gas furnace, also known as a condensing furnace, is the most efficient furnace available on the market today:

• They use a secondary heat exchanger to capture latent heat from flue gases by condensing water vapour that normally goes up the chimney; the main difference when compared to a mid-efficient model.
• A high-efficiency furnace can provide annual energy savings of up to 30 per cent, significantly lowering overall heating costs.

As of December 31, 2009, all natural gas and propane furnaces smaller than 225,001 British Thermal Units (BTU) per hour must have a minimum AFUE of 92 per cent, as regulated by the Province of Manitoba.

In addition to your natural gas savings:

• The installation of a high efficiency furnace can create a more uniform temperature and reduce building operating costs.
• These high efficiency units also promote cleaner air by reducing greenhouse gas emissions.

Any new heating system should always be sized correctly. Needlessly over-sizing a furnace to ensure adequate heating capacity will cause it to cycle on and off more frequently, reducing the life of the unit. Properly sized equipment should:

• improve operating efficiency;
• reduce capital costs;
• improve occupant comfort.

It is important to discuss optimal sizing requirements with your contractor.