Be sure to understand some basics of gas heating systems before you make that all-important purchase!
What’s the main difference between 80% and 90%-95% Efficiency Units? In an 80% efficient system, gasses are hot enough that they need to vent conventionally into the chimney stack. In a 90%-95% efficient system, the gasses are much cooler and vent to the outside via an exhaust vent, similar to a clothes dryer.
AFUE (Annual Fuel Utilization Efficiency): Indicated as a percentage, your furnace’s AFUE tells you how much energy is being converted to heat. For example, an AFUE of 90 means that 90% of the fuel is being used to warm your home, while the other 10% escapes as exhaust with the combustion gasses.
Combustion Air: Combustion air is the air used to properly burn the fuel for your unit.
Heat Exchanger: This is the part of a furnace that transfers heat to nearby air; the chamber where fossil fuel is burned. An improperly sized heater will cause expansion and contraction of the heat exchanger, which can lead to premature aging and cracks.
Venting Types: Your new gas unit will vent the combustible gasses in one of two ways – via a direct vent system or into an existing chimney. In many cases, the chimney will need to be relined in order to generate the correct draft and keep combustion elements, which are acidic, from eroding or corroding the inside of the chimney.
Single-Stage Gas Valve: A Single-Stage Gas Valves operate on a basic on/off principle. Each time your themostat calls for heat, your heating system comes on at 100% capacity.
Two-Stage Gas Valves: A Two-Stage Gas Valve is capable of two levels of operation — a low stage and a high stage. Properly sized equipment will operate 60-70% of the time in low stage, enhancing energy efficiency and comfort with perfect humidity levels and quieter operation. It’s almost like getting two heaters in one.
Standard Blower: A standard blower delivers a specified amount of air flow based on a tap setting.
Variable-Speed Blower: This high-efficiency blower is designed to deliver a varying amount of air flow based on the desired outcome. This type of blower increases the effectiveness of humidification, dehumidification, air filtration and balance of air flow.
Humidification: This is the process of adding moisture to the air by using an in-line whole house humidifier. During the winter months, heated air can make your house too dry. Adding moisture protects your furnishings, reduces static electricity, and helps people with respiratory sensitivities to dry air in the winter. Coupling a humidifier to a variable-speed blower gives you the ability to manage your humidity to a more precise level that you would like.
Indoor Air Quality (IAQ): This refers to the cleanliness and healthiness of the air in your home. Many factors affect air quality: smoking, pets, location of the property, age of the home, tightness of the house, etc. Perhaps the biggest enemies of indoor air quality are allergens – microscopic particulate matter, bioaerosols and volatile organic compounds that can produce allergic reactions, impede breathing or make you sick. Dust, pollen, germs, mold, and chemicals – all can be in the air. The wrong heating system can house, spread and recirculate these allergens.

