Best Gas Furnace Service in Indianapolis

A gas furnace’s energy efficiency is expressed as AFUE, which stands for Annual Fuel Utilization Efficiency. Shown as a percentage, AFUE indicates how efficiently a gas furnace uses the natural gas it consumes. Lower AFUE furnaces produce less heat per unit of energy consumed, while higher AFUE furnaces produce more heat per unit of energy consumed.

New gas furnaces cannot have an AFUE lower than 80%. High-efficiency gas furnaces offer an AFUE of 95% or higher. How efficient a gas furnace uses its fuel impacts a homeowner’s operating costs over the furnace’s years of service. Lower AFUE furnaces are more expensive to operate than higher AFUE furnaces because they consume more natural gas which results in higher energy costs.

In Indiana, ENERGY STAR® gas furnaces have a 95% AFUE or more. Purchasing a new gas furnace that is ENERGY STAR®-rated provides up to 15% higher energy efficiency compared to base model furnaces, generating energy savings up to $85 per year.

The range of gas furnaces on the market today include single-stage, two-stage, and variable-speed operation. The stages of operation refer to the capacity at which the blower motor is able to operate and distribute warmed air through the home.

• Single-stage furnaces only have one operating stage, which means they run at full capacity at all times. Because this type of furnace always works at its maximum capacity, it is the least energy-efficient option for homeowners with lower AFUE ratings.
  
  
• Two-stage furnaces offer two different operating capacities – high output and low output. Typically, the furnace runs on low and switches to high output during very cold periods, as the home can require assistance reaching a comfortable state when the temperature differential between indoor and outdoor air is high. With the ability to operate at a lower setting, a two-stage furnace runs quieter than a single-stage furnace and also uses less electricity to operate the blower motor.
  
  
• Variable speed furnaces utilize an electronically commutated motor (ECM) for the blower, which is able to run at different speeds to achieve precision control over the home’s airflow. An advanced variable speed gas furnace technology results in reduced energy use and higher AFUE ratings, quieter operation, and improved comfort inside the home, as variable speed operation creates a finer balance between air temperature and relative humidity.

The stage may also refer to the heating system’s gas valve and burner operation. These stages also affect how much energy is used by the furnace during operation.

• A single-stage gas furnace has a gas valve that flows at a single high rate, so the unit always operates at full capacity. This burns the most fuel, so single-stage gas furnaces typically have lower AFUE ratings.
  
  
• A two-stage gas furnace offers adjustable gas flow between high and low rates, between 70% and 100%. Lower capacity is utilized most often to conserve fuel, with the option for higher capacity operation when needed.
  
  
• A multi-stage or modulating gas furnace has a burner that adjusts electronically in order to deliver the precise amount of heat needed to achieve the temperatures set by the home’s thermostat. This variable speed model operates at the lowest capacity most of the time to conserve natural gas, and such units have higher AFUE ratings.

The heat exchanger is the component of a gas furnace which gives off heat to air that passes over the component before the warmed air is circulated into the home. It keeps combustion gasses from the furnace’s combustion chamber separate from the home’s air supply to prevent dangerous carbon monoxide exposure.

All gas furnaces have one heat exchanger inside the model cabinet. Many high-efficiency gas furnaces now include a secondary heat exchanger. In a furnace with two heat exchangers, when the byproducts of combustion exit the primary heat exchanger, they enter the secondary heat exchanger, which provides the opportunity for more heat to be released from combustion byproducts for use heating the home’s air. In the secondary heat exchanger, water vapor starts to form from the byproducts, which produces latent heat and further improves the high efficiency of the unit.

Additional features you may encounter while shopping for gas furnaces benefit the model’s energy efficiency, environmental friendliness, and user-friendliness. These may include:

• Low NOx, which releases fewer nitrogen oxide emissions.

• Capacity, the furnace must be properly sized for the home to operate efficiently and produce ideal comfort levels.

• Hot surface ignition or silicon carbide ignition, which eliminate the pilot light found in older gas furnace models for better energy efficiency.

• Advanced filtration for better indoor air quality.

• On-board diagnostics and maintenance reminders.

• Communicating technology.