Understanding Conventional HVAC systems

Know How it Works


The conventional HVAC unit, which is typically found in established homes, has three functions: heating, air conditioning/cooling, and ventilation.  Understanding how the cool or warm air is produced in the unit will help you to understand the importance of regular HVAC maintenance.


Conventional central air systems have an air compressor that uses refrigerants or coolants to cool down air in the house. The air is brought in from the outside and heated via coils. The units don’t make cold air like a furnace produces hot air. The coolant or refrigerant flows endlessly to remove the heat from the house. The air is passed through a condensing coil and an evaporator coil. The job of the condenser coil is to transfer heat. Air coils are a part of the heat exchangers and are in HVAC units. An evaporator coil absorbs the heat from the air in your house. That is where the cold air comes from. The evaporator coil is found inside the air handler or on the furnace. After the air passes through the coil a fan pushes the air into the house. The coils work together to produce the desired effect in your home. After the refrigerant works its magic on your air, it goes through a copper tube to the condenser unit, which is the actual box located outside your home. This box contains lots of different things, like fans, hoses, valves, etc. Once it makes it way to the outside unit the heated refrigerant gas enters a compressor that turns it into a high-pressure gas that is hot. When it cools it turns it into a liquid and then flows back into the system.


Conventional furnaces run on natural gas. A burner inside a combustion chamber mixes the gas with air. A pilot light ignites the gas. The flame heats up the heat exchanger, and this is where the air is heated and flows into the home. The air is controlled by a thermostat. The gas is vented outside via flue that goes through the wall or roof. Remember furnaces need servicing once a year to prevent carbon monoxide poisoning and to run efficiently.


Remember airflow is critical for condenser and evaporator coils. It is important to keep these clean of debris and dust. Proper ventilation keeps HVAC units running properly. Regular servicing by a professional is imperative to keep your family safe and your unit in good shape.

Schneider Heating & Air Conditioning, Inc., is the leader in heating, cooling, ventilation and air quality products and services in the La Crosse Area. We have been serving the Coulee Region for more than 80 years.  Our technicians are highly and continually trained utilizing the most sophisticated HVAC (Heating, Ventilation and Air Conditioning) technologies and equipment. All of the service technicians are NATE certified.  North American Technician Excellence is the largest non-profit certification organization that is governed, owned, operated, developed, and supported by the HVACR industry. And as an alliance of industry-recognized partners, you will have a greater peace of mind knowing we are sending out the right person for the job!  At Schneider Heating and Air Conditioning INC. we pride ourselves on amazing customer service!