How Modulating Furnaces Provides These Benefits

May 19, 2017

How Modulating Furnaces Provides Benefits

If your old furnace gave you fits this past winter, either because of breakdowns, poor efficiency/high utility bills, or old age, it's probably time to consider an upgrade.

Two-stage or modulating furnaces should be your focus if you decide to proceed with replacing your old furnace. A modulating furnace provides energy-efficient heating with better whole-house performance than an old-school single-stage furnace.

Your Old Furnace

You likely are still using a single-stage, mid-efficiency model that only operates at one level, 100 percent. With these furnaces, the gas valve has only two settings, closed and totally open, and the furnace's blower motor only operates at two speeds, off and 100 percent. The result of this limited type of operation is short cycling during days when it's not extremely cold outside. The furnace, receiving the thermostat's signal to turn on the furnace, kicks into full-go operation, quickly warms the house to the thermostat setting, then shuts down till it turns on again. This process – also called short cycling – repeats itself over and over with short intervals between on and off.

Short cycling wastes energy because furnaces generally consume the most electricity at start-up, so lots of starts means lots of energy wasted. Not to mention, the 100 percent operation when the furnace is running uses up more fuel and electricity. The start-and-stop operation also can result in uneven heating, with noticeable temperature swings.

A New Modulating Furnace

Modulating furnaces feature variable settings. The gas valve can open at intermediate levels, responding to the home's real-time heating needs. The blower motor, meanwhile, comes with variable-speed operation. Typically, a modulating furnace will begin operating at full capacity till the thermostat temperature is met, then will back off to a slower, lower-stage operation. It will continue running, nearly continuously, which uses less energy than short cycling and provides more consistent heating throughout the house. Indoor air quality is also improved, since household air cycles through the filtration system many more times a day.

Is It Time to Discuss a New Furnace?

To discuss a new modulating furnace for your Des Moines area home, please contact us at Lozier Heating & Cooling.