A lot goes on behind the scenes to ensure that a facility runs efficiently and keeps occupants comfortable and safe. For example, HVAC systems are a huge part of what keeps the inside of a building at the ideal temperature. Let’s break down everything about commercial HVAC basics to better understand how they function and keep our environment habitable.

What is HVAC?

Heating, ventilating, and air conditioning (HVAC) equipment regulates a building’s temperature and provides fresh outdoor air to dilute interior airborne contaminants, such as odors and dust. A properly designed and well-maintained system will keep the indoor environment comfortable year round.
One important thing to note is that, in New York City, water is mainly used for heat rejection during the cooling process (cooling towers and chilling) due to limited rooftop space. Here’s a list of other HVAC components found in NYC commercial buildings and how they work together to keep your building at the perfect temperature.

    Air Conditioner

    An air conditioner is designed to dehumidify and remove heat from the area. Cooling is done through a refrigeration cycle.

    Condensing Unit

    The condensing unit is connected to the evaporator coil. It’s installed by contractors outside of your building and filled with refrigerant gas. Once the refrigerant has been cooled into a liquid by the heat exchange, the condensing unit pumps the liquid to the evaporator coil to be evaporated into a gas.


    Refrigeration is the process that allows air conditioners to remove heat from inside a building and carry it outside, thereby lowering the indoor temperature. In an air conditioner, refrigerant absorbs heat from a room in the evaporator coil, causing it to change from a cold liquid refrigerant to a warm, low-pressure refrigerant gas. It’s the compressor’s job to squeeze the refrigerant gas, reducing its volume and turning it into a hot, high-pressure gas.

    Air Handler

    The air handler is used to condition or circulate the air. An air handler usually contains a blower motor as well as heating and cooling elements, filter racks or chambers, sound attenuators, and dampers. Air handlers are usually connected to ductwork that distributes the conditioned air throughout the building and returns it to the handler.


    A chiller removes heat from a liquid through a vapor compression or absorption refrigeration cycle. This cooled liquid flows through building pipes and passes through the coils in air handlers, fan coil units, or other systems, cooling and dehumidifying the air in the building. There are two types of chillers: air-cooled or water-cooled. Air-cooled chillers are usually outside and consist of condenser coils cooled by fan-driven air. Water-cooled chillers are inside a building and carry heat by recirculating water to a heat sink as an outdoor cooling tower.

    Evaporator Coil

    The evaporator coil has the opposite role of the heat exchanger; it cools air when the thermostat is set to lower temperatures.


    Ductwork refers to the system of ducts that transports air warmed or cooled by the system to the various areas of your building. Ducts are commonly made of lightweight aluminum.

    What Is an HVAC SEER Rating?

    A Seasonal Energy Efficiency Ratio (SEER) rating is a mathematical ratio for an air conditioner’s cooling output over a typical cooling season. Air conditioners with higher SEER ratings need less electricity to produce cool air than air conditioners with lower SEER ratings. The higher the SEER rating, the more efficient an air conditioner is.

    The Department of Energy regulates the minimum SEER rating for air conditioners, which is currently a rating of 13. An AC unit with a SEER rating lower than 13 does not meet current federal standards.

    What Does IAQ Stand For?

    IAQ stands for indoor air quality. It’s the measurement of how effectively your HVAC system produces and circulates healthy air throughout your facility. A system with good IAQ generates clean air that contains few pollutants (dust, dirt, and bacteria). A system with poor IAQ produces polluted air that can make building occupants uncomfortable and even sick.

    If your HVAC system consistently produces air with poor IAQ, have your HVAC contractor look at your system. They can determine what repairs it needs or whether you should replace your HVAC system.

    How Long Should My Commercial HVAC System Last?

    A commercial HVAC system requires an investment of several thousand dollars, so you’ll want the equipment to last a long time. You can expect an average lifetime of 10 to 15 years. By taking care of your system with regular HVAC maintenance, you can avoid costly repairs and ensure your system lasts for a long time.

    Professional Commercial HVAC Services

    Commercial HVAC companies can manage your HVAC so you don’t have to worry about keeping up with it. A professional HVAC and mechanical contractor like React Industries can make sure your commercial HVAC units are compatible with your building management systems. We provide repair and maintenance for your facility so you can focus on what’s important: running your business. Contact React Industries today for professional HVAC services.