How An AC Unit Works

Published on: August 30, 2012

Heating, ventilation and air conditioning, or HVAC, systems are intricate devices as they heat and cool your home. With all three operating elements in one unit, you’ll have a system that will warm, cool and dehumidify your home.

The air from your HVAC system moves to each room of your house through ducts. When you install an HVAC unit, you’ll have a handy and quiet way to provide comfortable temperatures throughout your home year-round.

How Your AC Operates During the Summer

When you have a central air conditioner or heat pump unit, you have a split system as the device includes an outside element, which is the condenser, along with an indoor mechanism called the evaporator coil.

During the operation of your system, the unit will transfer air from one section to another. For instance, when you use the AC unit, the system will remove warmth from your home’s inside air and shift it outdoors. After it removes the heat from your home, it will circulate the remaining cool air with a fan.

Your system also contains a substance called refrigerant, which transports heat within the unit. The compressor in your HVAC system has the job of altering the unit’s vaporous refrigerant into a gas that contains high temperatures and pressure. When the gas moves through the condenser coil, the vapor will lose heat. During the condenser’s processing of the gas, the substance increases in temperature and pressure while it becomes a liquid. The liquid will then move through your unit’s copper tubing and into the evaporator coil.

Once the refrigerant reaches the evaporator coil, it expands, which reduces the liquid’s temperature and pressure. After the gas becomes a low temperature, reduced pressure gas, it will soak up the warmth from the air that is moving in your home’s ducts. At the same time, the gas is shifting back to your HVAC system’s compressor.

During the air cooling process, your AC unit will also remove the moisture from your home’s air. While the warm air moves over your system’s evaporator coil, it is unable to contain the water. Therefore, the moisture shifts towards the exterior of your system’s coils and through the drain. You can compare the process to the condensation that occurs on the outside of a glass of ice water.

Your HVAC Unit’s Winter Operations

When your HVAC system heats your home during cold weather, it will take warmth from the outdoor air. If you have a geothermal unit, then it will remove heat from the ground. Once the unit extracts the heat, it will shift the warm air indoors to the evaporator coil, which will distribute the heat throughout your home.

Heated Air from Winter Temperatures

Your HVAC system will pull the heat for your home from cold exterior air. Even if the winter air temperature is 30 degrees, it will contain heat. Keep in mind that air without any amount of heat will be colder than -200 degree Fahrenheit. Therefore, your system can pull a lot of heat from the winter air in your climate. Once the unit draws cold air into the heat exchanger, it will alter the cold temperature air into warm air. Your system’s fan will then send the air into your home.

If you live in a cold weather environment, then your system may have a back-up heating device, which will help your system heat the cold air.

The HVAC Ducts in Your Home

When you have an HVAC system installed in your home, the device will need ductwork to distribute the air within your residence. Your ductwork will contain bendable tubes that include insulation. When your home contractor installed your ducts, he or she placed them across the floor of your attic and underneath your home.

If you live in an older home, then you may consider contacting our service experts to complete a leak test. Keep in mind that you spend approximately 44 percent of your home’s energy on heating and cooling. Therefore, you’ll want to ensure that your ducts are not leaking. When we complete an assessment of your ducts, we’ll review your system’s design as improper duct planning can cost you energy dollars.

In some cases, ducts can be too small for the space they must heat and cool. Additionally, ducts can be too large, which can cause air intended for one room to be sent to the room with larger ducts.

System Options

Depending on your area’s climate, you may choose to install a packaged AC unit, which unites the condensing system and the evaporator coil. We would install your packaged unit outside. Once we evaluate your residence, we can recommend the best system for your climate and home.

When you contact our company for AC maintenance, we can show you the different elements of your HVAC system.