Glossary of Terms

At Durastar, we aim to help our customers better understand which heating and cooling equipment will help them achieve maximum comfort year-round. One way we accomplish this is by breaking down common HVAC acronyms and terms. Be sure to check out our other resources like How To Talk To Your Contractor and Things To Consider When Replacing Your HVAC System.

HVAC acronyms and terms - technical glossary

AC Float Switch

An AC float switch is a great accessory for preventing condensation overflows and potential leaks. Imagine if you were on vacation and your AC drip pan began overflowing without detection. It could cause some serious water damage. However, if you have installed a float switch, also known as a condensate overflow switch, then it would shut down the air conditioner as soon as it detected extra water in the drip pan or drain pipe. As a result, these small safety switches prevent big (and costly) disasters.

AFUE

Annual Fuel Utilization Efficiency (AFUE), is a standardized measure of efficiency for how furnaces and boilers convert energy to useable heat.

Air Conditioner

An air conditioner, or AC unit, cools your home by removing heat and humidity. This is accomplished using an evaporator coil, which collects the warm air, and a condenser coil which releases the collected air outside.

Air Handler

An air handler, also known as a fan coil, is generally paired with a heat pump. Together they create a heating and cooling system. Air handlers are the indoor component and they move air over a coil which then heats or cools the air. After that, it distributes the air throughout your home via ductwork.

Amp Draw

Amp draw measures the amount of effort or energy it takes to run a piece of equipment.

BTU

BTU, also known as the British Thermal Unit, is a measure of both heat loss and gain. Specifically, it measures the heat given off when fuel is combusted; or when cooling, it measures the heat that is extracted from a space. Talk with your contractor to determine how many BTUs are ideal for your home. Too many or too few BTUs will cause excess energy costs, unnecessary wear and tear, inconsistent temperatures throughout your space, and other adverse results.

Capacity

In terms of HVAC systems, capacity refers to the maximum output of a unit. In other words, a system’s ability to heat or cool a specific amount of space. The larger the unit is, generally, the greater the output. For cooling, capacity is measured in tons; and for heating it is measured in BTUs.

CFM

CFM stands for cubic feet per minute. In regards to HVAC systems, CFM is measuring airflow. Specifically, how many cubic feet of air passes over a single point in the span of one minute. When a system has a high CFM rating, it means a greater amount of air is being forced through it.

Coil

Coils are a key component of air conditioning and heat pump systems. In fact, evaporator coils and condenser coils are responsible for continuously circulating refrigerant between indoor and outdoor components.

Decibel Rating

Decibels are a measurement of sound. The lower the decibel rating (dB) the quieter your equipment will operate.

ECM

ECM is short for electronically commutated motor and uses less wattage than a standard motor. This type of motor is also referred to as a variable-speed motor. It enhances the efficiency of your HVAC system by lowering the amount of energy required to maintain consistent airflow in your home. Due to the motor’s microprocessor, it is able to regulate the airflow based on the demands of the environment. As a result, it will operate at the lowest power output in order to maintain the designated temperature.

EER2

EER2 is an energy efficiency rating specific to air conditioners and cooling systems. The higher the EER2 rating, the more energy-efficient your air conditioner operates.

ENERGY STAR®

HVAC equipment with the ENERGY STAR symbol has met strict energy efficiency criteria set by the US Environmental Protection Agency. The ENERGY STAR rating was established to help reduce greenhouse gas emissions caused by inefficient energy consumption. These products can often help reduce your monthly utility bills.

Furnace

A furnace heats air which is then distributed throughout your home via ductwork.

Global Warming Potential (GWP)

This is a standard method of measurement and comparison for global warming impacts of different gases. The lower the GWP, the lesser the impact on the atmosphere. For more information, reference Understanding Global Warming Potentials. Regarding HVAC equipment and its GWP, we generally refer to the impact of the relevant refrigerant. For example, Packaged Terminal Heat Pumps with R32 offer customers a more efficient product with fewer global warming impacts.

Heater Kit

A heater kit, also known as a heat kit or auxiliary heat strip, is an accessory for your air handler. Generally, air handlers do not heat or cool, but rather move air. However, if you install a heat kit, then it will supplement your heat when outdoor temperatures are extremely low.

Heat Pump

A heat pump is an outdoor unit that uses electricity to both heat and cool your home. They operate by extracting heat from a nearby space and then transferring it to another space. Because the unit transfers heat, rather than generating it, it can be more energy efficient when compared to other equipment such as air conditioners or furnaces. However, discuss all options with your contractor because there are many factors to consider when deliberating energy efficiency, such as your climate and home’s specifications. These units are generally paired with an air handler.

HSPF2

Heating seasonal performance factor, or HSPF2, measures the efficiency of a heat pump. The higher the HSPF2 rating, the greater the likelihood of generating monthly energy savings.

Inflation Reduction Act

The Inflation Reduction Act is a legislative package that incentivizes energy efficiency improvements, such as new or updated heating and cooling systems. To review the 2023 updates, download this helpful PDF and learn about your potential tax incentives.

Mini-Splits

A mini-split is a ductless and discrete heating and cooling system. Each system has an outdoor compressor that is connected to one or more indoor units. Mini-splits are an ideal solution for individualized, zone-specific temperature control. Build with Ferguson offers a vast selection of mini-split units available for direct purchase, however, we recommend working with an HVAC professional to both determine the best combination of equipment and to ensure proper installation. Please note that warranties may be voided if the product is not installed by a licensed HVAC contractor.

SEER2

SEER2 stands for Seasonal Energy Efficiency Ratio 2. It is an efficiency measurement used to compare air conditioners and heat pumps. The higher the SEER2 rating, the more efficient the equipment operates.

Stages

In HVAC, stages represent the available operating capacities. For example, a single-stage system is either on, using full power, or off. Whereas a two-stage system can operate at two capacities; generally using either 60-65% power or 100% power. Likewise, three-stage systems often have LOW, MEDIUM, or HIGH settings. Units with multiple stages are likely to generate energy savings and can better adjust to varying outdoor conditions to maintain consistent performance and evenly distributed indoor temperatures.

Ton

Ton or tonnage is a unit of measurement that measures how much heat an AC unit removes in one hour. When selecting a new air conditioner, it is important to determine the optimal tonnage for consistent, reliable temperature control. In order to do so, you will need to know the square footage of your space. Discuss these details and more with your contractor to ensure you invest in the best HVAC system for year-round comfort.

M1 Equipment Transition


In 2023, the US Department of Energy (DOE) updated energy efficiency testing standards. It now uses M1 testing with the intention of reducing energy consumption in the US. In compliance with the new testing standards, we now have M1 equipment available. Please see below for more details about each product category.

Durastar A2L Refrigerant Transition


In compliance with the 2020 American Innovation & Manufacturing (AIM) Act, Durastar products will begin transitioning to A2L refrigerants in 2024. Continue reading for more information about the transition and how it will impact Durastar products.

Let’s Talk About Types Of Air Conditioners


AC units come in all different shapes and sizes, with features that range from humidity control and quiet operation to compact design. In this article, we help you determine the best air conditioner for your space.

Lower Your Air Conditioning Bill This Summer


Summer is all about having fun in the sun. Unfortunately, between family trips and backyard barbecues, expenses can add up quickly - but, don’t let your utility bill be one of them! Durastar is swooping in with some insights regarding ways to lower your air conditioning bill this summer.

Do I Need A New Air Conditioner?


Unexpected air conditioner breakdowns usually deliver more than a few hot nights - they can be expensive, too. Asses the dependability of your AC Unit with a few tips from our experts.

Get a complete HVAC system from Durastar and optimize energy savings


When installing a new heating and cooling system in your home, opt for ultimate performance and convenience. Rely on Durastar, your one-stop brand for energy-saving HVAC products.

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