Give Us A Call: 919-480-2727

Back to Blog

Furnace Buying Guide – How to Pick the Perfect Furnace for Your Raleigh, NC Home

When it’s time to replace your furnace, you’ll have to pick out a brand-new furnace for your home. But how do you know what furnace is best for your home’s heating needs? Furnaces come in a variety of sizes, types, and efficiencies. It’s easy to become overwhelmed by all your options. That’s why we’ve provided a furnace buyer’s guide to help you understand your different options and what you should consider when picking out your new furnace.

Basic Furnace Design Options

Furnaces consist of two or three main components depending on their fuel source. Oil, propane, and gas furnaces use a burner to combine fuel and air and then burn the mixture to produce heat. This heat is transferred to the air via a heat exchanger. In electric furnaces, the heat exchanger converts the electricity into heat. Lastly, a blower then distributes the warmed air throughout your house.

Burner Options

Furnace burners are usually designed to operate in one of three ways.


The most common burner is a single-stage burner. A furnace with a single-stage burner has two operating modes, on and off. Single-stage furnaces will always operate at the rated capacity, regardless of conditions inside or outside of your home. This can lead to inefficiency when conditions are mild.


Two-stage burners are designed to address the inefficiency of single-stage burners. A furnace with a two-stage burner has three operating modes, off, low-fire, and high-fire. The high-fire mode produces its full rated capacity. The low-fire mode allows your furnace to operate at some factory-set level that’s less than the maximum capacity. This allows your furnace to better match your home’s heating requirements when the weather is mild, leading to a more comfortable home and lower utility bills.


Modulating burners can operate at almost any output. They have a minimum and maximum heating capacity but can operate at almost any point within this range. Modulating furnaces are able to eliminate large temperature swings by constantly monitoring conditions and adjusting output to account for any changes. They also maximize efficiency by using the minimum amount of fuel to satisfy heating demands.

Blower Options

Furnace blowers come in two main options: multi-speed and variable-speed. A multi-speed blower allows our technicians to select a speed for each type of operation at the time of installation. This blower then operates at the designated speed when the associated operation is required.

Our technicians also set the operating conditions for variable-speed blowers at the time of installation. However, instead of picking a speed that provides the approximate amount of air flow rate desired, the speeds on variable-speed often correspond to a specific air flow rate. Your furnace will then monitor flow rates, temperatures, and other information and adjust the blower operation to maintain ideal conditions.

Venting Options

Furnaces have two primary venting configurations. This first is chimney venting. These furnaces have large vent connections and rely on the natural buoyancy of hot air to exhaust combustion gases and draw fresh air into the furnace. These vents require large chimneys to work correctly.

Higher-efficiency furnaces have built-in inducer blowers to assist with exhaust spent gases and pull fresh air through the furnace. These are called direct vents and can be used either vertically through a ceiling or horizontally through a side wall. Direct vented furnaces use smaller venting than chimney vented furnaces do and pull fresh air directly from outside.

Factors to Consider When Buying a New Furnace

Buying a new furnace is a big financial investment that shouldn’t be taken lightly. When you’re in the market for a new furnace, consider the following factors before making a decision:

  • What kind of furnace should you get? Consider if an oil, gas, or electric furnace will work best based on your needs. Talk to one of our HVAC technicians to learn more about the advantages and disadvantages of each furnace type.
  • What size furnace do you need? This is usually measured up in energy units called BTU. Our HVAC installers will be able to determine what BTU or heating capacity your home needs based on its size, the number of people living in it, and the temperature you’d like the maintain.
  • What level of efficiency are you looking for? The more efficient your furnace is, the less energy it will use to heat your home. Efficiency is measured in AFUE. New furnaces typically have an AFUE rating of 95% or higher.

Call Air Experts for Furnace Replacement Services in the Raleigh-Durham Area

You don’t have to go through the furnace buying process alone. Our knowledgeable team is ready to help you choose the right furnace for your home’s heating needs. Once we’ve determined the best furnace for you, we’ll handle all your installation, repair, and maintenance needs during the lifetime of your new furnace.

Contact us today at 919-480-2727 to schedule a service or speak with an HVAC technician about your furnace needs. We’ll be happy to answer any of your questions.

$25 Off Any HVAC or Plumbing Repair
Expires 05/31/24 Call for details. Must present coupon at time of service. Normal business hours only. Cannot be combined with other offers.
Enjoy Stress-Free Comfort At Home for as little as $129 per month EASE Comfort® Program
Expires 05/31/24 *Available with approved credit.