How an HVAC System works


Modern central air conditioning systems are described in industry terms as HVAC systems or Heating, Ventilation and Air conditioning.

In South Florida, heating is of such little concern in our daily lives that we normally just call them ac or air conditioning systems.  It is all really the same thing.

The main goal of our HVAC systems is to make our indoor air spaces comfortable and provide clean air. We never think about them until they break and we are trying to understand what all of the parts mean.


Air Conditioning: How your HVAC system cools your house

Most air conditioners installed in residential homes in Florida are split air conditioning systems.  That just means that part of the system is outside, and part of it is inside.  The split air conditioning system helps to provide ventilation, humidity control and keep the noise down inside.

HVAC air compressor
Air Compressor

The split system is made up of a compressor outside and an air handler inside.  A coil sits on top of the inside air handler with an air return and a series of duct work throughout your house.


Your air conditioner starts its work when the thermostat signals to the air return that it is time to come on.  The air return brings in the warm air with the power of the fan that is powered by the air handler or furnace.  The air passes through the filter, which removes small particles and cleans the air.  The main purpose of the filter is to protect the air conditioning unit. Partials can damage the air handler if they pass through.  The filter removes harmful allergens and dust from the air.


The outside compressor unit pumps a chemical refrigerant from a gas to a liquid. The liquid refrigerant goes through the inside coils to cool them.  The warm air passes over the cold coils and the air is cooled. The moisture is removed through condensation and sent back outside.  This is how your air conditioner helps to reduce the indoor humidity.   The heat from the air transfers into the refrigerant in the coils and goes back to the outside unit to cool again.


HVAC: Heating


The heating function works much in the same way.  The colder air passes over a heating element in the air handler or furnace.  Warm air returns through the ducts work and back through the vents in your house.  The air is cleaned through the filtration system.  Heating air doesn’t produce the same condensation and humidity control as cooling it.  In the winter your air conditioner isn’t providing the same humidity control as it does in the summer.  Many Floridians find that a separate dehumidifier helps to keep homes comfortable in the winter.

HVAC systems provide essential indoor air quality and comfort in Florida homes and businesses.  They provide heat, ventilation and air conditioning so that we can live in comfort.



HVAC Repair Service40 Degrees Air and Refrigeration is a family owned air conditioning repair company with over 20 years of experience serving the greater Miami-Dade County and Broward areas.  Call us at (305) 733-2501 for any of your HVAC or air conditioning repair need.