When cooling effectively, your air conditioning system should usually never run for more than 15 to 20 minutes at a time even when the outdoor temperature is in the 100s. The only time the system should really ever run for much longer at a time is when the temperature in your home is far above what you have the thermostat set at. If you find that your AC is running for much longer each time, it means that there is some issue that’s preventing the system from cooling effectively. With that in mind, here are some of the most common issues that can cause a central air conditioning system to cool much more slowly than usual.
1. Age
The effectiveness of your air conditioning system will always decrease with age. The older the unit gets, the more slowly it will cool, the longer it will need to run and the higher your energy bills will be. The average lifespan of a new central AC unit or heat pump is usually around 12 to 15 years, but it isn’t uncommon for units in Las Vegas to start failing after only eight to 10 years because of the extreme heat. If your AC is nearing the end of its life and struggles to keep your home cool, it is definitely time to start considering a replacement.
2. Lack of Maintenance
Regular maintenance is absolutely essential for keeping your air conditioning system functioning effectively. If you don’t have your AC fully inspected and professionally maintained every year, it will quickly start cooling far less effectively and running longer. Inspection is obviously important for ensuring that the system doesn’t have any major issues and doesn’t need any repairs. When maintaining the system, the AC technician will always clean, check and calibrate all of the components to ensure everything functions effectively and the system is working as energy efficiently as possible. Annual inspections and maintenance are also important for protecting the life of all of the components.
3. Dirty Air Filter
The first thing we would always recommend any time your AC starts cooling more slowly is to replace the air filter. The general recommendation is that the AC air filter should always be replaced every one to three months. In places like Vegas where your AC will get far more use and run for many more hours each day, you typically won’t want to go more than six to eight weeks without replacing the filter since it will get dirty and clog up more quickly.
Air filters are designed so that air can easily flow through them, but most dust and debris will get trapped. As the filter gets dirtier, it will start to greatly restrict how much air can flow through it. This will force the blower to work harder and also result in much less warm air coming into the air handler where your AC evaporator coil is located. This reduction in airflow means that the system won’t remove nearly as much heat from your home at one time and cause your AC to cool much more slowly.
4. Dirty Evaporator Coil or Condenser Coil
The evaporator coil inside your home works to remove heat from the air, and the condenser coil in the outdoor AC unit then releases all of that heat back outside. If the condenser coil is dirty and covered in a layer of dust, it can essentially become insulated to where the warm air flowing through the system can’t come into direct contact with it and the system removes heat much more slowly. This issue can also cause the evaporator coil to start freezing because the refrigerant isn’t absorbing enough heat and thus stays cold enough that the condensation that forms on it begins freezing.
A dirty condenser coil can also cause your AC to cool much more slowly. What happens in this situation is that dirt and dust again insulate the coil so that all of the heat in the refrigerant can’t be properly released into the surrounding air. In turn, this causes the refrigerant to be warmer when it flows back inside, which means it won’t be able to absorb as much heat and the system will cool more slowly. Luckily, both of these problems can easily be prevented with annual maintenance as this includes fully cleaning both the evaporator coil and condenser coil.
5. Debris Clogging the AC Condenser
Most AC units have removable perforated panels on all four sides, and underneath these panels is a wire grille. The panels ensure that air can easily flow through the unit, which is important for ensuring that the unit can release all of the heat it removed from inside your home. The grille underneath the panels acts as a barrier to help prevent lots of leaves and other debris from getting drawn inside the unit.
Over time, this grille can become almost completely clogged by debris. This problem is especially common in areas with lots of poplar trees and cottonwoods as all of the cotton or fluff produced by these trees can easily get sucked inside and start to clog the sides of the unit. When the sides are clogged, the fan won’t be able to circulate air through the unit properly. This can then create the same issue as a dirty condenser coil as the refrigerant won’t be able to release all of the stored heat and will remain warmer, causing the system to cool more slowly.
6. Malfunctioning or Worn-Out Blower
If the AC blower isn’t working effectively or is starting to wear out, it will also reduce how much warm air comes into the system just as when the air filter is too dirty. Again, this will greatly reduce the system’s cooling rate and can potentially lead to the evaporator coil freezing. If the blower motor is the culprit, it will either need to be repaired or replaced.
7. Air Leaks in Your Ductwork
All central HVAC systems have two separate duct systems. There is the return air duct where warm air flows in and to the air handler and the supply ducts where the cold air is then circulated to every room. Small leaks in the return air duct typically won’t have a major effect, but leaks in the supply ducts can definitely cause your AC to cool more slowly. This is especially the case if the ducts in the unconditioned spaces of your home like your attic or crawl space are leaking since this will result in much of the cold air escaping instead of flowing out into your home.
Leaky ductwork can also greatly increase your energy bills as it can result in anywhere from 20-30% of the energy used by your AC system being wasted. Most leaks can easily be fixed by repairing, resealing or potentially replacing the affected areas. However, if your ductwork is more than 20 to 25 years old, you’re probably best to replace all of it since it will typically have many leaks and not last much longer anyway.
8. Poorly Insulated Attic Ducts
Any ducts that run through your attic should always be fully wrapped in insulation. Attics always absorb lots of heat from the sunlight beaming down on your roof. When the temperature outside is around 100 degrees, the temperature in your attic can easily reach 170 degrees or more. If your attic ducts aren’t insulated, all of that heat can make the sheet metal extremely hot and cause the air flowing through the ducts to also become much warmer. This can greatly reduce the effectiveness of your AC and potentially cause those rooms supplied by your attic ducts to receive no cooling at all.
At BEST Air Conditioning Plumbing Repair, our technicians can take care of any issues your AC has and get it working properly and cooling effectively again. We offer professional repair and maintenance services for all models, brands and types of central air conditioners, heat pumps and ductless mini-splits, and we can also help with all of your home’s heating and plumbing needs. Contact us today if you need to schedule an AC inspection or any other service.
