By Ryan Mayes
Basics of Preventative HVAC Maintenance
Most car owners understand how regular maintenance like oil changes, tire rotations and filter changes can go a long way towards maximizing performance. It’s a small price to pay to extend the life of the vehicle. The same goes with air conditioners. And, understanding the value of air conditioner maintenance means understanding a little more about how your air conditioning unit works.
In most cases, your central air conditioner is actually a system that includes an indoor unit and an outdoor unit connected by copper tubing and electrical wiring. The complete system often both heats and cools your home, depending on the types of equipment installed. Keeping all parts of the system in good operating condition can be vital to your comfort, your system’s efficiency and helping keep utility bills in check.
- Outdoor unit – Also called a condenser unit, the typical outdoor unit includes the large condensing coil that usually wraps around most of the unit, a compressor, a fan and motor and electronic controls.
- Indoor unit – Either a furnace or a fan coil, the typical indoor unit houses an evaporator coil, blower fan and fan motor, and an air filter.
Here's how it works
- With the help of the compressor in the outdoor unit, a chemical refrigerant circulates between the indoor and outdoor units, through copper tubing called “refrigerant lines.”
- Heat energy is pulled from indoor air though the evaporator coil and exits the system through the outdoor condensing coil.
- Cooler air is blown back into the home through ductwork, and heat energy escapes outside.
During normal air conditioner operation, dust, dirt, moisture from humidity or condensation, and microbial growths can build up on internal components. Left unchecked, these issues can corrode components like the evaporator coil and condenser coil. Over time, those components can become less effective and lead to a loss of efficiency or worse, a shorter air conditioner lifespan.
Regular AC maintenance and tune-ups can minimize many of the issues caused by build-up of dirt and debris. If they are performed by an HVAC technician, these inspections allow your contractor to check for longer-term issues and in some cases take proactive steps to prevent premature failure or inconvenient breakdowns during the cooling season.
Annual air conditioner preventative maintenance may also be a requirement to keep your warranty valid as well. Many manufacturers state on warranty documentation that installation and maintenance by a licensed HVAC service provider are a part of the warranty conditions.
Figure 1: Sample Diagram of Air Conditioner
Clean the Air Conditioner
One simple way to potentially save money and prolong the life of an AC system is to make sure the outdoor unit stays clean. During normal operation, a fan in the outdoor unit pulls air through the condenser coil. Airborne dust and dirt particles and debris from nearby foliage can get lodged in the coil fins, restricting airflow and affecting performance. Four air conditioner preventative maintenance tasks that can keep the outdoor unit clean:
- Removing debris/foliage: Trim back or clear the area of shrubs or flowers that can restrict airflow to the unit. Physically remove any leaves or other debris that has accumulated near the base of the unit or is clinging to the side of the unit.
- Vacuum the coil fins: Your dealer will turn off the system either at the thermostat, the power cutoff near the outdoor unit, or the breaker box. Once they have ensured the system is disconnected from power, they will vacuum the coil, which wraps around most of the outside of the unit using a soft bristle brush attachment. Most AC coils are composed of refrigerant tubing and thin metal “fins” that bend easily. Your dealer will be careful not to bend the fins as this can also restrict airflow and affect performance.
- Cleaning the coil fins: Your dealer will turn off the system either at the thermostat, the power cutoff near the outdoor unit, or the breaker box. Once they have ensured the system is disconnected from power, they will clean the coil fins with heavy-duty coil-cleaning chemicals and using a garden hose (NOT use a power washer – too much pressure can bend or damage the fins), they will gently rinse dirt and debris from the coil starting at the top and moving down.
- Cleaning the evaporator coil: The indoor evaporator coil also requires airflow for proper operation, but because it is typically difficult to access, we recommend leaving cleaning AC coils to a licensed Carrier indoor comfort expert.
Replace the Filter
One of the easiest air conditioner preventative maintenance tasks you can perform yourself is to clean or replace your system’s air filter. The air filter for your AC system will be located in or near your indoor unit. Whether it is a basic 1-inch filter, a larger, 4-inch media filter or a more sophisticated electronic air cleaner or purifier, the filter should be cleaned or replaced periodically. These air conditioner filters can help with indoor air quality by removing airborne particles and pollutants from your home. They can also help keep your system operating at its peak performance by reducing the buildup of dust, dirt and other particles from accumulating on internal components like the blower motor.
How often to change air filters depends on a number of factors:
- The quality and type of filter
- Environmental issues such as pets and smoke from a fireplace, tobacco or cooking
- If you or family members suffer from allergies or asthma
- How often the system runs due to thermostat settings/personal preferences
- Use of constant fan for air circulation
It’s a good idea to check and inspect your filter at least once every 2-3 months. Some filters, such as the wider 4-inch media filters can last up to 1 year before replacing. Whenever possible, follow your manufacturer’s recommendations for filter maintenance. In general, to clean or replace your AC system filter, follow these steps:
- Turn off system power at the thermostat, the breaker box, or the power shutoff switch located on/near the indoor unit.
- The exact location of the filter can vary depending on the indoor unit. Look for the filter along the sides, top or bottom of the blower cabinet. The filter may be positioned horizontally or vertically, depending on the model. Or in some cases, especially on older models, the filter may be found inside the blower cabinet.
- Once you have ensured the system is disconnected from power, remove and inspect the filter for excessive dust buildup or debris. Clean the filter with a vacuum attachment or replace with a new filter.
- Make sure the filter is positioned properly and that the airflow arrows are pointing in the correct direction.
- Replace the cabinet cover and restore power.
Know When to Call a Professional For Air Conditioner Maintenance
While it’s true that regular air conditioner maintenance can help prolong the life expectancy of your air conditioning system... and there a handful of DIY maintenance tasks that can be performed by an average homeowner... there are times when it’s just best to call a certified HVAC technician. Some signs that it’s time to make the call might include:
- System is not cooling adequately or not running at all
- System is constantly running for long periods of time
- System turns on and off frequently
- Copper refrigerant tubing or outdoor coil showing signs of icing up or freezing
If you are experiencing any of the above issues, a trained technician can further evaluate your cooling system during their air conditioner maintenance visit. If you don’t have trusted contractor in mind, follow the link to our dealer locator to find a Carrier HVAC dealer in your area.
You may also visit our Air Conditioner Repair page, Air Conditioner Maintenance page for more information or our mini split ac repair and troubleshooting guide or our mini split ac repair and troubleshooting guide