An HVAC system keeps the inside of our homes comfortable. But how do residential HVAC systems really work?
What is an HVAC System?
An HVAC system is what keeps your home cool during the summer, and warm during the winter. HVAC systems are what help us stay comfortable all year-round in our own homes. An HVAC system (or Heating, Ventilation, and Air Conditioning) system is made up of several different parts and often uses electricity or gas to operate.
Depending on the kind of HVAC system you have, your system may be made up of equipment like:
The furnace: A big part that is designed to heat air
An evaporator coil: Cools down air when the thermostat is set low
Condensing unit: The unit outside your home that’s filled with refrigerant gas
Refrigerant lines: Carries refrigerant gas to the condensing unit
Vents: Distributes heated or cool air throughout your home
All HVAC units will have a thermostat of some kind for you to set the indoor temperature.
How do Residential HVAC Systems Work?
The best way to describe how an HVAC system works, is that an HVAC system moves air. An HVAC unit is meant to carry warm air either from one part of your home to another, or from the inside of your home to the outside. And vice versa!
Each part of an HVAC system is connected to one another, and most parts rely on the other parts to work correctly. If one part of an HVAC system fails, it’s not just that one part that will stop working – it will likely impact your whole unit.
That’s why an HVAC system is described as “system.”
How an HVAC Heats The Air
First, the furnace of an HVAC system will generate heat, either through electricity or gas. Then, a heat pump will push the warm air that’s generated through your vents and into your home.
A heat pump does not actually generate heat itself. Instead, it absorbs and moves heat from one place (like your outdoor unit) to somewhere else, like inside of your home.
How an HVAC Cools The Air
Believe it or not, an HVAC system doesn’t cool air. The heat pump will absorb the warm air from the inside and vent it back outside.
The refrigerant in an HVAC system is a key part of this process. Refrigerants can change its forms depending on air pressure. It can either be a liquid or a gas. An HVAC system will modulate the refrigerant so that the system can then take in, and remove, the heat inside a home.
So, instead of cooling a home, an HVAC system is actually removing hot air from the inside and then circulating the cooler air that’s left.
How Should You Maintain an HVAC System?
Regular maintenance of your HVAC system will keep it performing at its best, save you from costly repairs and high energy bills, and keep the air you breath clean. Routine servicing of your system is far less expensive than having to repair individual parts or even a whole system.
Here are a few signs your HVAC system could use servicing:
High energy bills (your HVAC system may not be running efficiently)
Loud noises from the system (most noises beyond its typical start and stop sounds are not a good sign. If you hear loud banging or clanks from your system, it’s time to call in an HVAC professional.)
No heat or cool air (this is the most obvious sign your HVAC system has an issue. Regular maintenance will help you avoid this during the hottest parts of summer or the coldest parts of winter.)