There are several options available when it comes to the blower assembly in a new furnace. Choosing the most efficient option for your replacement furnace is good for both your wallet and for your home's comfort.
A standard blower was the industry standard until fairly recently, and it is still the type of blower used on many furnace models. Standard blowers are fixed speed, which means the fan only blows on a single high setting. This means quick heating when the furnace pops on due the drastic blast of warm air, but it can also mean higher energy costs due to the extra energy pull to run constantly at a high speed.
Another concern is the evenness of the heat. Since the blower only runs at high speed, the temperature typically swings between the low when the furnace pops on and the high as the drastic blast of heat is sent out.
Variable Speed Blower
Just as the name implies, a variable speed blower operates at different fan speeds. These blowers use a thermostat that more closely monitors temperature changes throughout the house. Not only is the temperature monitored, but the rate of temperature change is also tracked. This way the blower can respond at a speed that meets the actual conditions. If cooling is slow, the blower will run at a lower speed and provide gentle warmth. During times of rapid cooling, the blower responds at a higher speed so it can quickly counteract the drop.
Not only does this save on energy costs, but it also can prolong the life of the blower. A blower that is constantly running at full speed is more likely to suffer wear and tear, which means more maintenance visits. Variable speed blowers may not need as frequent of repairs.
Multi-speed blowers are not quite variable speed blowers, but they are still a step up from standard one-speed blowers. Multi-speed blowers typically have two speed settings — high and low.
In some designs it is up to the user to determine which speed to adjust the blower to, so the thermostat will be equipped with a fan setting option. Other furnaces switch between two speeds automatically. Multi-speed blowers aren't quite as efficient as variable speed blowers, but they are a good compromise if you can find a variable speed option that fits your needs or budget.
Contact a furnace installation service to learn more about the blower types available for your furnace replacement.