What is HVAC?

HVAC stands for Heating, Ventilation, and Air Conditioning.

Whether it’s the dead of winter and the elements are as harsh as your mother-in-law’s criticism or you’re a walking puddle in the middle of August, a home’s HVAC system is what ensures your family is provided with a temperate, pleasant refuge from the great outdoors. Your HVAC system is critical to the comfort your home provides. HVAC stands for heating, ventilation, and air conditioning, and it simply refers to the system that heats, cools, and ventilates your home. HVAC systems vary and there are various manufacturers, styles, and types. The HVAC (generally) includes the heating and cooling unit itself, lots of ductwork through the home, air returns, and air filters.

Types of HVAC systems

There are three main types of HVAC systems: split and window AC, packaged heating and air conditioning systems, and central AC systems.

Split and window air conditioning systems

Split ACs are used in larger areas than window ACs. The split AC focuses on splitting the cold from the hot side of the system. The cold side has the cold coil and the expansion valve. This is usually placed inside a furnace or any other form of air handler. The handler blows air over the coil and the cooled air is distributed to various rooms in the building through the air ducts.

Window air conditioners work by fans blowing air through the coils, improving how they separate the heat and cold. Heat gets lost the outside air and is replaced with cool air for the room.

Packaged heating and air conditioning systems

Hence the name, this type of system is the total package, they possess both heating and cooling equipment in a single unit. Users can place them in mechanical rooms, on the rooftop or at a grade close to the conditioning space. The package AC has all the components in one unit, unlike split systems in which the cold and hot units are separate. These elements have a centrifugal fan or blower that helps distribute the air throughout the elements of the structure.

Central air conditioning

Most of the air conditioners in residential buildings are in the form of split systems. The compressor and condenser are combined as a single condensing unit mounted outdoors. The evaporator, a finned coil, is mounted in a section of ductwork within the furnace blower. Two flexible refrigerant lines, one for gas and one for liquid, connect the components. When the furnace is electric, a blower is included in the system. The compressor uses electricity as its source of power to pump the refrigerant across the system collecting indoor heat and removing it from the home. The heat dissipates outdoors by the coil in the condensing unit.

Warm air indoors gets blown through the indoor coil (cold) to remove moisture and heat. The heat in the air transfers to the coil and thus the air cools. The water vapor condenses on the coil and collects inside a drain pan. It goes outside through the condensate drain. The heat, after flowing to the evaporator coil, pumps outdoors while the now cooled air inside the room circulates through the fan on the air handler. Thus, the indoor temperature is maintained.

Give your HVAC system a big thank you

When all is working as it should with an HVAC system, it is a silent soldier for the home's comfort. However, if your HVAC system has ever malfunctioned or broken in the middle of the winter or summer, it’s likely you have developed a deep love and appreciation for the essential service your HVAC system provides. So, take care of your system; baby it, even. Be sure to change your filters frequently and on a regular schedule, as well as get your system cleaned, inspected, and serviced annually!

Alec Lower

Content Writer

Alec is a third-year member of the team at Second Nature. He brings expert knowledge of a myriad of home air filtration topics including HVAC filters, filtration efficiency, and indoor air quality.