When testing, remember this is only a laboratory rating and rarely equals actual installed equipment performance.

Two numbers in gas-fired equipment typically identifies its AFUE rating. One digit or number buried within the nomenclature can be trickier to spot than a sequence of numbers or letters. In this example, the equipment stages are typically identified by a number or symbol in the model number. Once you master the nomenclature of your favorite manufacturer, it becomes easy to find and learn others. With less than an hour’s study on your manufacturer’s website, you will begin to identify the characters used to classify the equipment types your company offers. Condensing units, heat pumps, cooling or heating coils, and package units also follow this pattern. These letters or numbers group equipment into categories such as furnaces or air handlers.

Consider the EL in this model number as a code name for a group of similar equipment. Most model numbers begin with the series or equipment type. Example is available as a download at the end of this article.Īlthough each manufacture’s nomenclature is a little different, here is a sample from a Lennox gas furnace that provides an example of what each of the numbers and letters represent. Let’s take a look at how to read and interpret equipment nomenclature. By learning to interpret the code, you can increase your ability to repair, test, diagnose, and sell upgrades. The problem is, this information is imbedded in the model number and must be interpreted to be useful. Each piece of HVAC equipment has a nameplate containing features and details.

Rheem serial numbers nomenclature hvac