Basic Components of a Commercial HVAC System

For most in the Hartford area and beyond, little thought is given to commercial HVAC systems commonly found in office buildings, malls, stores, and other buildings across the city until these systems fail and the building is sweltering hot or bitingly cold. Though a commercial HVAC system is similar to that of a residential one, due to the sheer size of the buildings that most systems have to accommodate, there are some variances in the components that make the commercial systems function. Today, we are going to discuss the elements that make up the system that cools the building during these hot summer days.

Air Conditioner

An air conditioner is one of the parts that both a commercial and home HVAC unit have in common. An air conditioner’s main purpose is to dehumidify the air and, of course, remove the heat from the building. The air conditioner alone does not cool the building, there are many parts and sub-elements that contribute to cooling the building.


For the building to cool, heat must be removed from the air and transferred somewhere else. The condenser is the unit responsible for transferring heat from the air and carrying it away. To summarize, the condenser is the hot side of the air conditioning unit: a heat exchanger.

Air Handler

The air handler of the system is used to circulate the air through the building and commercial HVAC system. Usually, this is the part of the system that is connected to the ductwork; it blows the cool or heated air into the building and then returns it to go through the system again via the air handler again. Other parts of the air handler includes a blower, heating and cooling elements, racks, chambers, sound attenuators, and dampers.

Terminal Units

The terminal units can also be called blower coils or fan coil units and are made up of an air filter, coil, and blower. The size of these varies with larger units conditioning 100 percent outside air and none of the circulated air. These larger units are known as MAU’s: make-up air unit. Units that are on the roof are called RTU’s or rooftop units.


A chiller does exactly what it sound like. It removes the heat from the liquid that will run through the pipes of the building and eventually pass through the coils of the air handlers, fan-coil units, or other systems. There are normally two types of chillers: air-cooled chillers and water-cooled chillers. An air-cooled chiller is condenser coils that are cooled by fan-driven air and is normally located outside. Water-cooled chillers are as they sound: chilled by water that is continuously recirculated when needed. The water is recirculated to carry heat away and deliver cool water from an outside cooling tower.

These are just the basic functions of the components that make up the cooling system of a commercial HVAC system. To learn more about commercial HVAC systems, energy efficiency, automation, Tradesmen of New England and our services, stay tuned for more on our blog!

Does Your HVAC Need Maintenance?

Is your building not cooling properly or are you experiencing exorbitant energy bills? Contact the commercial HVAC technicians of Tradesmen of New England. We offer services backed by experience and the knowledge to get your system running efficiently once again. We can retrofit older systems properly, install the latest automated systems, and also handle your electrical needs. Visit our website to learn more about us, our services we provide to the Hartford-area, and to schedule an appointment!