Why Is My AC Blowing Hot Air?
Learn about HVAC & Home Performance in Houston.
Texas gets hot in the spring, summer, and fall. If your air conditioning goes out or starts blowing warm air, it can be very uncomfortable. When you need air conditioning repair, get the expert heating and cooling specialists at House Pro to help.
If your AC goes out during the summer months, you may have to wait for a while to get an appointment. It is always best to get regular maintenance.
If your AC is blowing hot, there are a few things that might be at the root of the problem. To understand any of these problems, it is important to understand how an air conditioner works.
How Air Conditioners Work
There are several different models of air conditioners but some things make them all the same. All air conditioners cool a room by removing heat from the air. They have two coils that are connected. The coils have refrigerant flowing between them. There is a coil inside the room that is being cooled called the evaporator (because it evaporates heat.) There is a coil on the outside of the building called the condenser. The evaporator must be colder than the room temperature and the condenser must be hot for the air conditioner to work properly.
The refrigerant’s job is to absorb the heat from the room and push it outside to the outdoor unit. For this to happen, you must have a compressor and an expansion valve located inside the air conditioning unit. When all the components work together, they will convert the refrigerant from gas to liquid and back again in a continuous cycle.
A compressor’s job is to increase pressure and in this case, it increases the pressure on the refrigerant. The compressor receives the refrigerant when it is in its gaseous state. As the gas is compressed, it will become hotter and it will pass through the heat exchanger easily. The compressor coil will convert the gas into a liquid state. When the liquid refrigerant reenters the room and enters the evaporator coil, it will evaporate and cool the indoor coil.
At this point, a fan inside the air conditioning unit will blow air from the room across the evaporator coil. The refrigerant will absorb the heat and the process will begin again. This will go on until the room reaches the temperature that is set on the thermostat and you will feel the cool air.
When your air conditioner will not cool your home, it is normally because there has been an interruption in the flow of refrigerant and the heating and cooling system.
5 Most Common Causes of an Air Conditioner Blowing Hot Air
There are several different reasons that an air conditioning unit will blow hot air into your home. The trained professionals at House Pro can help you with every one of them.
- Unmaintained Condenser Unit
The outside condenser needs to be in an area that is free of clutter. If something is obstructing it such as bushes or an object, it cannot do its job properly. Hence you should always trim any weeds or grass that are outside of the condenser.
If you live in a rental unit or condominium, and you notice weeds are grass around the condenser area, you should ask your maintenance crew to get rid of the vegetation going around it.
In some cases, a condenser may simply become dirty. Debris from trees may fall into the condenser’s casing. The condenser’s casing should be cleaned regularly. We will always clean it as part of the maintenance package. We clean each coil and straighten any bent coils with a coil fin. We use the very best cleaners and have a great technique for getting condenser coils spotless.
- Insufficient Airflow
In some cases, the air conditioner might not have proper airflow. You can hold your hand up to the vent to see if you feel anything. However, a better way to gauge the airflow is to hold a match-up to each vent in your home and see if the airflow is strong enough to make the flame move. It should move no matter where you are in the room.
- Thermostat Problems
In some cases, you may think that you are having airflow problems with your air conditioner when it is the thermostat that is not working properly. Your thermostat may simply have died of old-age or you may need to replace its electrical board.
A thermostat may not work simply because the battery has died. If you have a thermostat that uses batteries, you should check to make sure that they are still functional. The AC may simply have blown a fuse, in which case all you will have to do is reset your fuse box.
- Low Refrigerant
Low refrigerant is one of the most common reasons that an air conditioner will blow hot air. Refrigerant simply flows from the inside to the outside of a home. It does not evaporate and you should not have to replace it. If your refrigerant is low, you probably leak a hose. House Pro can find the leak and replace the hose. We will send out a competent HVAC service provider who will work quickly and efficiently.
- Dirty Air Filter
One of the main things that can cause insufficient airflow is if the air conditioner’s filter is dirty. You should change your air conditioner’s filter at regular intervals. The exact frequency of your air filter changes will be determined by the type of air filter you have and your personal needs,
In some cases, the ducts in your home may be dirty. When we come to do or repair, House Pro can clean ducts if they are impeding the airflow in your home.
If you find yourself replacing your air conditioning filter very often, you may be using the wrong kind of filter for your circumstances.
You want to use the highest quality filter you can without putting too much strain on your air conditioning system.
The quality of an air conditioning filter is determined by its ability to capture small particles in the air. The smaller the particles in the air conditioning filter can capture, the higher its rating will be.
MERV stands for Minimum Efficiency Reporting Value. MERV standards are set by the environmental protection agency. They are rated on a scale from 1 to 20.
MERV Rating of 1 to 4
Filters with a MERV rating of below four can only capture particles of 10.0 microns or higher. These filters will capture things such as dust from construction projects, pollen, and carpet fiber. They are used mostly in commercial buildings or furnaces. It is not recommended for a person’s home.
MERV Rating of 5 to 8
Filters with a MERV rating from 5 to 8 will usually be used in commercial buildings and some apartment buildings. You can stop those that are 3.0 to 10.0 microns in size. It can capture mold spores, standing dust, and pollen.
MERV Rating of 8 to 12
A filter with A MERV rating from 8 to 12 is recommended for residential homes. These kinds of filters are often used in hospital laboratories. It can capture microns that are 1.0 to 3.0 in size. It can capture many particles including:
- Cement dust
- Coal dust
- Lead dust
- Humidifier dust
- Nebulizer dust
MERV Rating of 12 to 16
Filters with a rating of 12 to 16 are used in some operating rooms. People with superior air conditioning systems in their homes might be able to use these filters. They can capture particles from 0.3–1.0 microns. This includes auto fumes and d nuclei.
There are filters with ratings of 16 to 20 that are used in sterile operating rooms and pharmaceutical laboratories.
It may seem as though higher is better. However, if you get a filter with a MERV rating that is too high, It may end up weakening the airflow. A top-quality filter needs extra small pores to trap the tiny particles that it does. Those tiny pores make it hard for air to get through certain kinds of air conditioning systems. Your air conditioning manufacturer should recommend a certain kind of filter for your system. You should always use the highest number filter that the manufacturer suggests.
The material a filter is made out of will also affect the efficacy. Inexpensive filters are made out of paper and generally need to be changed once a month. There are titanium filters that can last up to a year.
If you have recently had an air conditioning replacement in your home, or if your home is brand new or new to you, the air conditioning unit itself may be an improper size or it may have been installed poorly. We can assist you with proper installation. If your air conditioner is the wrong size for your home, we may be able to modify the unit, although in most cases, it will need to be replaced.
When You Need to Call a Professional Contractor
If you changed the filter and made sure that your thermostat is set properly, and you have not blown a fuse, it is a good idea to call house pro for the expert cooling system technicians based in Houston. One of our trained techs will be out in a hurry to make sure your home is cool. If you need a ac upgrading, we can help you with that as well. Give us a call today.