Few things are as frustrating as turning on the air conditioning in your home only to be greeted with warm or, in some cases, downright hot air. Unfortunately, this phenomenon is one that many homeowners encounter when they turn down the thermostat setting on their home’s air conditioning (AC) unit in hopes of cooling off. That’s because nearly all homes have AC. According to the U.S. Energy Information Administration, over 90% of homes in the U.S. have AC, mostly central AC systems.
With so many components having to work collectively to cool a home, AC failures sometimes happen. And those failures can result in the AC system blowing warm or hot air when turned on. That’s according to HVAC experts in Alabama, including those with One Hour Air Conditioning & Heating in Pelham.
How Do Air Conditioning Systems Keep Homes Cool?
To better understand why an AC system might blow warm or hot air, we should probably take a moment to familiarize ourselves with how they work. When an AC system is on, warm air inside a home passes through an expansion valve and then over evaporator coils filled with refrigerant. The evaporator coils absorb heat from the air before turning it into a gas and sending it to a compressor, which acts as a pump, decreasing the volume of the gas and raising its pressure and temperature before finally passing it on to a condenser. The condenser fan then removes the gas, now in vapor form, out of the home to cool it off. Many things can go wrong in this complex process. And when they do, it can lead to an AC system blowing warm air instead of cold air.
Common Reasons Why an Air Conditioning System Might Blow Warm or Hot Air
Sometimes, an AC system might blow warm or hot air if there is a problem with the thermostat in the home. For example, some homeowners might inadvertently set their thermostats to heat instead of cool. That alone can cause warm or hot air to come out of the air vents in the home. Having the fan on the thermostat set to “on” instead of “auto” can cause the same issue. The same applies to not setting a cool enough temperature on the thermostat. Fortunately, these are minor problems that most homeowners can resolve themselves. Aside from thermostat problems, the following can also cause an AC system to blow warm or hot air:
- A Tripped Breaker – If a home experiences an electricity surge due to a lightning strike, electrical overload, faulting wiring, or another electrical problem, it can trigger a tripped breaker. When this happens, the compressor, condenser, and other components that help send cool air into the home may stop working. In most cases, returning the tripped breaker to the “on” position is enough to resolve such an issue.
- A Dirty or Clogged Air Filter – Although often overlooked, a dirty or clogged air filter can cause warm or hot air to blow when an AC system is running. According to most air conditioning manufacturers, homeowners should replace the filter in their AC systems every 30 days. Dirty or clogged air filters can cause critical AC system components, such as the motor, fan, or compressor, to break down and stop working, which could lead to the system blowing warm or hot air.
- A Clogged Condensate Line – All AC systems produce water as a byproduct of keeping a home cool. To get rid of the water, they have a condensate line that consists of a pipe or tubing that removes excess moisture. If the condensate line becomes clogged, the compressor in most AC systems will shut down, causing the system to blow warm or hot air. Scheduling annual air conditioning maintenance with a licensed HVAC technician can prevent this from happening.
- Low Refrigerant Levels – Because refrigerant is a cooling agent responsible for absorbing heat and leaving cool air behind when it passes through an evaporator and compressor, it can cause problems if levels fall too low. One of those problems is an inability to cool the home. Low refrigerant causes the air blowing from the vents in your home to feel noticeably warmer. Resolving this problem will require contacting an HVAC technician who can identify and fix the cause of the low refrigerant levels and add more refrigerant to the system.
- A Malfunctioning Compressor – Since the role of an AC compressor is to compress the refrigerant that keeps the cooling evaporator coil cold, a malfunctioning compressor would make it difficult for an AC system to cool a home. Refrigerant leaks, electrical problems, blocked condenser coils, and overheating are some of the things that can cause a compressor to malfunction. Along with warm or hot air, telltale signs of a malfunctioning compressor include frequent tripping of circuit breakers in the home, loud banging noises, and higher-than-usual utility bills. Fixing or repairing a malfunctioning AC compressor will require the expertise of a licensed and experienced HVAC technician.
In summary, from the very minor to the large and complex, multiple things, including forgoing regular maintenance, can cause an AC system to blow warm or hot air. To learn more or to schedule an AC repair, consider contacting One Hour Air Conditioning & Heating today.