What is the difference between a traditional furnace and a variable speed furnace?
Technology has increased greatly in the heating and cooling industry over the last 10, even 5 years. For example, let’s compare a traditional furnace to a variable speed furnace. The difference is like comparing a regular light switch to a dimmer switch. With a traditional furnace the heat switches on until your home reaches a certain temperature and then switches off. A variable speed furnace operates like a dimmer switch, it can be turned down (“dimmed”) when your heating needs are less demanding and then turned up when your comfort needs increase.
“Variable speed” actually refers to the furnace’s indoor air blower motor. The blower motor is the component that determines the amount of air the blower is required to deliver to your home. A variable speed blower motor moves at different speeds to precisely control the flow of heated and cooled air throughout your home.
A variable speed furnace works by using sensors to control the flow rate of the flue through the burner. On chilly – but not cold – days, the furnace runs at the low setting, but for a longer period of time. This allows it to operate at the most efficient temperatures without the many stops and starts that create inefficient burning. Conversely, on cold days it burns at full capacity to accommodate the more demanding workload. Most variable speed furnaces run at low setting approximately 90 percent of the time.
In addition to saving money, running the burner and blower longer at a lower setting distributes air in rooms more evenly and pushes more air through the furnace filter, resulting in cleaner air. Saving money and better indoor air quality, this technological improvement sounds like a winning combination!