Check the AFUE rating.

Not all so-called energy-efficient furnaces are created equal. Energy efficiency is best determined by the furnace's Annual Fuel Utilization Efficiency (AFUE). The AFUE rating measures how efficiently a furnace turns fuel into energy. The higher the rating, the more efficient the furnace.

ENERGY STAR®-certified furnaces have an AFUE rate of 95% or higher. So, if you see that ENERGY STAR label, you know it will save you energy and money.

Check the fan motor.

The fan motor in a furnace is critical to its efficiency! An inefficient fan motor will sap unnecessary electricity. Even if the furnace is a highly efficient model, it must have the fan motor to match. Look for models that run on direct current (DC) or feature an electronically commutated motor. Avoid an alternating current (AC) motor.

Make sure it’s the right size.

Sizing your furnace to match your home’s space and heating needs is vital. An oversized furnace will cycle on and off too often, causing uneven heating and wasted energy. A furnace that is too small will struggle to keep your home comfortable, which defeats the purpose of investing in a new one! A trusted HVAC professional will measure your home so you can buy a furnace that fits perfectly for your space and needs.  

Look for a two or multi-stage furnace.

Your furnace doesn’t always need to run at full power. A two-stage furnace allows it to run at a lower speed in milder temperatures, gradually increasing to meet your desired temperature. It runs at a higher setting when it's colder to ensure you’re toasty and warm. Single-stage furnaces are a little cheaper initially because they have fewer parts. But two- or multi-stage furnaces will use less energy and save in the long term, which is worth the upfront cost.  

Upgrade your thermostat.

While you’re at it, upgrade your thermostat! Adding a programmable or smart thermostat can help you manage and maintain your energy use. You can program the thermostat to lower the temperature when you’re out for the day or sleeping at night. Plus, smart thermostats take that to the next level. They can learn from your daily habits and preferences and automatically adjust the temperature for maximum energy savings.