Not all gas furnaces are created equal. When looking for a gas heating system for your home, it is important to be familiar with the various types of gas furnaces along with their corresponding efficiency ratings and ignition systems. Read on to learn about the different types of gas furnaces offered and find the one that’s right for your home.
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How Does a Gas Furnace Work?
In order for a gas furnace to work properly, it needs to receive instructions from a programmable thermostat in your home. Next, an internal gas valve is unlatched to allow natural gas into the internal combustion area. The gas is sent to a set of burners in the ignition compartment of the furnace. Depending on the type of gas furnace you have, a standing pilot light or electronic ignition system will be utilized to light the gas burners.
Standing Pilot Lights
Older gas furnaces utilize a miniature gas valve and standing flame to work and provide heat to your home. To ensure the pilot light is activated at all times, this small valve is designed to provide gas to the pilot light throughout the day. This type of gas furnace also includes a thermocouple that is engineered to continuously check the pilot light to ensure it’s lit.
Once the gas furnace receives data from the central thermostat, the thermocouple will confirm the pilot light is operating correctly. If the pilot light is in a good condition, the thermocouple will open the main gas valve of the furnace and allow the standing flame to ignite the burners. A Standing pilot light is wasteful since it relies on a continuous supply of natural gas. This is why this type of ignition system is no longer used in the latest types of gas furnaces on the market.
Electronic Ignition Systems
Modern gas furnaces are engineered with two types of electronic ignition systems, intermittent pilot lights and hot surface ignition. The types of furnaces that utilize an intermittent pilot light include a small flame that is designed to ignite the incoming supply of natural gas. Unlike a standing pilot light, an intermittent pilot is only lit when it receives a command from the central thermostat. An electrical spark is utilized to ignite the natural gas within the gas burners.
Other types of gas furnaces include a hot surface ignition system. This system includes a miniature metal component that is heated with electricity. Once this part reaches a sufficient temperature, it lights the gas within the burner of the furnace.
Regardless of the type of ignition system in your furnace, a combination of heat and gas is utilized to supply energy to the heat exchanger. This is a component that is surrounded by moving air in the furnace. Once the air is warmed by the heat exchanger, the air is pushed to the warm-air plenum. Lastly, the conditioned air is pushed out to each area of your home through air ducts.
AFUE Rating: What You Need To Know
The Annual Fuel Utilization Efficiency, or AFUE, is a rating system designed to measure the efficiency of different types of gas furnaces. The AFUE rating of a furnace indicates the percentage of fuel a furnace converts into usable heat. The scale ranges from 30-100, and the higher the number, the more efficient the furnace.
As an example, a furnace with an AFUE rating of 80 indicates that 80% of the fuel is turned into usable energy – the remaining 20% is lost through the furnace’s exhaust. Gas furnace types with higher AFUE ratings are more energy-efficient and can help you save on your monthly utility bill.
Single-Stage Gas Furnaces
Single-stage systems are the most common type of furnace used today, and the least expensive furnace option. Single-stage means these furnaces are either on or off, with no in-between. No matter what the temperature is outside, the furnace will run at its full capacity to heat your home.
While a single-stage system is the least expensive type of furnace to purchase, they are not the most efficient. Since a single-stage furnace only runs at one capacity, high, the furnace can often run on short-cycles, turning on and off frequently to heat the home.
Two-Stage Gas Furnaces
Two-stage furnace systems run at two settings, high or low. When this type of furnace notices a change in temperature, it adjusts accordingly and uses smaller amounts of energy to heat the home. This additional setting allows the furnace to provide more even heat to the home while using less fuel.
Two-stage systems cost more to purchase but end up saving homeowners money in the long run due to their more efficient fuel use. They also prevent hot and cold spots in the home, by providing consistent heat at lower fuel outputs.
Tips & Insights: Top Signs of Furnace Short Cycling Issues & Troubleshooting Steps
Modulating Gas Furnaces
Modulating systems are the latest in furnace technology. This furnace type uses computer-controlled thermostats and variable-speed blowers to provide consistent heat throughout the home. They operate at only the capacity needed to provide the heat the home needs, virtually eliminating fuel waste.
Modulating systems only use energy when needed and use only the amount of energy necessary to get the job done. Because of this modulating heat approach, they use the least amount of energy and are the most efficient of the furnace systems.
Let Team Electric Install Your New Gas Furnace
Having trouble deciding which type of gas furnace is right for you? We can help! Team Electric’s HVAC technicians are here to help you choose the perfect heating solution for your home. Our team of experts will provide a customized recommendation based on your preferences and the specific needs of your home. Our team provides dependable furnace repair, tune-up, and installation services to homes in areas of New jersey such as Middletown, Tom’s River, Elizabeth, Brick, and Trenton. Give us a call by phone at (732) 201-3305 or schedule an appointment online to receive help.