Why You Should Consider Upgrading to a High-Efficiency Furnace

Posted: 2019-01-08

A Spotlight on the Lennox ML193

If you’re using an older, low or mid-efficiency furnace, you have been spending too much to heat your home. Not only does an inefficient heating system burn more fuel, but it also fails to give you the comfort you need.

While it may still seem to work today, it might be time to consider replacing it with a more efficient unit, which can save you money in the long run and give you greater comfort now.

Four Seasons Air Specialists is your trusted heating company in Hugo MN that offers an array of high-efficiency furnaces designed by Lennox, one of the best names in home heating.

What is a High-Efficiency Furnace?

Since 1987, the U.S. Department of Energy has been setting Annual Fuel Utilization Efficiency (AFUE) ratings. AFUE is a measure of how efficient the appliance is in converting energy in its fuel to heat over the course of a typical year. Particularly, AFUE is the ratio of annual heat output of the furnace compared to the total annual fossil fuel energy it consumed.

As of May 1, 2013, the Department of Energy demands that all furnaces sold on the market should meet or exceed a minimum AFUE rating of 80 percent.

High-efficiency furnaces are those that are at least 90 percent efficient, which means 90 percent of the fuel you use is converted to heat and the remaining 10 percent goes up the chimney or elsewhere.


Because of the many features they offer, high-efficiency furnaces are recommended not only by professionals, but the U.S. government itself, which particularly presents a federal tax credit of up to 30 percent, or up to $1500 if you invest in a high-efficiency furnace for your home.

A high-efficiency furnace uses a second heat exchanger to capture much of the heat that would normally float up the chimney.

Blower compartments on high-efficiency furnaces are usually wrapped to maintain heat. Older heating systems normally are not insulated.

Certain high-efficiency furnaces also help you save money by allowing you to pair an advanced, programmable thermostat to a variable speed motor. This equips the system to run the blower for longer periods of time at lower speeds. It provides quieter and uniform, comfortable heat and doesn’t unnecessarily consume electricity.

Features of the Lennox ML193 Gas Furnace

Standard Features

With product registration, the ML193 may be eligible for a 10-year Limited Extended Warranty. Lennox also offers a 5-year Limited Warranty on covered parts and 20-Year Warranty on the Heat Exchanger.

Every component of the ML193 has proven itself through extensive testing in our research labs. So you can take comfort knowing the furnace will deliver reliable performance, season after season.

The ML193 offers continuous comfort at a smart price.  But value doesn’t mean compromise. It’s still built to exacting Lennox® standards, with the Lennox commitment to your comfort.

When the ML193 is paired with a Lennox® heat pump, it creates a system that can automatically alternate between electricity and gas to keep you warm. So you’re always using the most energy-efficient way to keep comfortable.

Energy Efficiency

Compared to older, low-efficiency models, the ML193 has an efficiency rating of 93 percent AFUE that can save you hundreds of dollars in heating costs per year.

When paired with a Lennox® heat pump, the ML193 creates a system that can automatically alternate between electricity and gas fuel to keep you warm. So you’re always using the most energy-efficient way to keep comfortable.

The blower compartment of the ML193 is tightly sealed, permitting less than 1% air leakage. This means more of your air and energy go toward keeping you comfortable.


The ML193 has a Duralok Plus heat exchanger that is constructed from patented ArmorTuf steel that captures waste heat, and a stainless steel secondary heat exchanger that allows the unit to achieve industry-leading efficiency levels. This solid component exceeds industry requirements and extends the furnace’s life.

Its SureLight® ignitor is designed with silicon nitride construction for long product life and reliable operation.

Its SureLight® integrated control board ensures full control of furnace operation.

To further lessen heat loss, Lennox designed the ML193 with an elegantly-styled, durable steel cabinet with high-quality paint finish.

Ask the Heating Maestros

For more information about high-efficiency furnaces, call Four Seasons Air Specialists. Since 1974, we have been your dependable Forest Lake furnace installation contractor serving you with passion and commitment to excellence.