All boilers and furnaces come with an efficiency rating that greatly influences your purchasing choices, but what exactly goes into that rating? For starters, there are a few types of ratings.’

Types of Boiler Efficiency Ratings

Commercial boilers typically use thermal efficiency ratings. Thermal efficiency measures the efficacy of the heat exchangers to transfer heat from the combustion process to the water or steam in the boiler. This figure is exclusive of radiation and convection energy losses. In short, the higher the percentage, the more efficient the water heater.?’

Other types of efficiency include:

  • Combustion efficiency is the burner’s ability to burn fuel, and it is measured by unburned fuel and excess air in the exhaust. Make sure your combustion chambers are filled with extra air; this will ensure the combustion of all fuel.’
  • Fuel to steam efficiency refers to the boiler’s overall efficiency, including the thermal efficiency of the heat exchanger, radiation and convection losses.

Furnace Efficiency Ratings

Furnace efficiency ratings are measured by The Annualized Fuel Utilization Efficiency (AFUE). AFUE is a fuel rating for warm-air, gas or oil-fired furnaces less than 150,000 BTUh. The most efficient units have higher AFUE ratings, while less efficient furnaces have a lower rating. According to the Department of Energy, the minimum AFUE percentage must be 78%.

Maintaining Efficiency of Your Boiler or Furnace

To ensure that your boiler or furnace is running at its most efficient rate, look out for red flags. A commercial boiler may need to be repaired or replaced if any of the following occur:

  • Leaking. If water is pooling around the water connections or under the unit, it could be leaking.
  • Boiling noises. The tank may make bubbling noises when the water heats up.
  • Slow recovery time. When it takes longer for the water to become hot, or does not attain the temperature that it used to, the unit may need repairing or replacing.

A commercial furnace may require maintenance or replacement if any of the following occur:

  • Inaccurate temperature. If the thermostat reads a certain temperature but the air is noticeably cooler, it may be time to look into the need for system maintenance, repair or replacement.
  • Age of the unit. Heaters can last anywhere from 15 to 25 years, and the age of the unit can be a factor in its efficiency and overall ability to function.

Efficiency ratings, as well as the cost of continued maintenance’play huge roles in deciding whether to repair or replace your unit . To improve the functionality and efficiency of your existing boiler or furnace, contact’American Boiler Company. Our knowledgeable, experienced technicians can help you get the most out of your boiler or furnace.