Is it odd to imagine that an AC unit that works all day during the summer can actually freeze up? This is a common occurrence in Indianapolis. Unfortunately, most people are unaware of measures to take to protect their air conditioners from freezing. A frozen AC unit can turn a beautiful summer day into a nightmare. Here are the possible causes of this type of AC problem.
1. Low Refrigerant
Refrigerant chlorodifluoromethane, also referred to as R22, is a common cause of AC freeze-ups. It has different physical properties that tend to change with pressure levels. A properly functioning AC system allows the refrigerant to pass through the lines at a temperature level where condensation may form outside the unit. A sudden pressure change can cause the refrigerant to act differently. The moisture will likely condense and freeze on the air conditioner as moist, warm air moves over the evaporator, resulting in ice buildup. Minor frost can result in a slight change in the performance of your air conditioner, but too much ice can interfere with the free flow of air.
The ice will eventually form an insulation layer and derail the functionality of your air conditioning system. Ice buildup will also increase the evaporation of the R22 refrigerant, and when it gets too low, your AC unit won’t be able to freeze the line. Sometimes the ice can melt to the extent of stopping the airflow problem. Still, the AC system may not be cooling your home at all. Your air conditioner is potentially damaged by water if it can no longer cool your indoor space. It’s recommended to have the AC system inspected by a professional as soon you notice a potential freeze-up.
2. Damaged Blower Fan
Air conditioners use blower fans to get cold air from outside when you want to cool your house during hot summer days. The air inside the AC unit becomes dense as your indoor air cools. Blower fans suck hot air from the outside to help move denser cold air out of your residence. The effectiveness of an AC unit to create cool air and push it out depends on its ability to maintain the correct balance of air pressure and airflow. Blower fans often get damaged or broken during normal operations. Malfunctioning blower fans can significantly alter the flow of air inside the air handler. As a result, ice will form on the coils and make it difficult for water droplets to drain or evaporate. Broken blower fans can also speed up the freezing of a refrigerant line. Be wary of a frozen refrigerant line, as the ice can back up to the condenser unit and cause problems.
3. Dirty Coils
Dirty air conditioner coils are a common cause of AC freezes. Ice buildup can obstruct the flow of air inside of an air conditioning unit. A little bit of frost can build up into a solid ice block. It’s common for evaporator coils to freeze, given that AC units are used for both dehumidifying and cooling the air inside of an office or a house. The role of evaporator coils is to pull water out of the air inside an air conditioning unit to prevent ice build-p. However, this isn’t a cause for alarm because the condensed droplets will eventually fall into the drip pan. However, never allow drip pans to overflow to prevent freezing of the coils. Dirt on top of the coils can cause freezing by preventing water absorption. Scheduling regular tune-ups with a professional HVAC service can help keep your AC unit’s coils dirt-free.
4. Poor Airflow
Poor airflow, or a lack of airflow, is the leading cause of AC units freezing up. Poor airflow can be the result of numerous factors, including air intake and the blower motor. If any component inside the AC unit prevents the flow of warm air over the coils, the air conditioner will likely start to freeze. For example, if something blocks the duct, the air won’t flow to the coils. Blocked or collapsed air ducts can prevent the free flow of air even if the rest of the AC system functions smoothly.
5. Incorrect Fan and Thermostat Settings
Too slow of a fan speed can prevent the air conditioner from transferring indoor heat to the outside. Homeowners do this when they want to minimize their appliance’s noise. Sometimes fans need to run faster to avoid overworking the AC unit. It also allows the circulation of more air through the coils. However, this doesn’t mean a higher fan speed can stop ice buildup. The only time homeowners should keep their fan speed low is when the humidity outside is high. A lower airflow can help the air conditioner to dehumidify more effectively. AC units are designed to cool a house at about 68 degrees. However, homeowners are free to adjust their thermostat and fan based on the weather conditions. Setting the temperature below 68 degrees can cause ice build-up.
6. An Inefficient Compressor
The efficiency of a compressor depends on how effective it is in pumping the refrigerant. Enough refrigerant is required to shut off the cold control on the air conditioner. Sometimes the temperature may get to a level that would cause the air conditioning system to shut off. Faulty compressors are often not fixable, so the best solution is to replace them. It may be practical to replace the entire AC unit rather than replacing or repairing the compressor.
7. Too Low of an Outdoor Temperature
It isn’t recommended to run an air conditioner when the outdoor temperature is below 62 degrees. Low outdoor temperatures can make the refrigerant inside the AC unit so cold that it freezes the indoor air before it circulates through the coils. Sometimes opening the doors and windows can be a viable alternative to running an air conditioner when outdoor temperatures are mild.
8. Faulty Drain Systems
The absorption of heat by indoor evaporator coils can cause moisture to condense onto the air conditioning unit. AC units are equipped with a drainage tube and catch pan to allow this moisture to drain outside a home. However, clogged drain systems can cause excess moisture to condense on the coils and form ice blocks as the AC unit extracts heat. The drainage tube could be blocked if your air conditioner isn’t dripping some water outside.
9. An Oversized Air Conditioner
Ice build-up tends to occur on an AC unit serving a smaller room than its capacity. An oversized air conditioner often experiences short cycles, making it turn on and off frequently. Short cycles can prevent the flow of air that keeps moist air from freezing up or condensing onto the AC unit.
10. Low Voltage
Low voltage can sometimes cause ice build-up on an air conditioner. Air conditioning units require a high power supply to keep houses at optimal temperature levels. Under-powered blowers or fans can cause freezing problems, especially when the compressor is running.
Whenever you find the need for a technician to look into repairing your air conditioner or heater, let us help bring comfort back into your home. We can also assist you with your plumbing needs, including tankless and conventional water heaters, sump pumps, standard plumbing services, 24-hour emergency repairs, as well as home performance audits and trusted solutions. Contact Peterman Heating, Cooling & Plumbing in Indianapolis today for more information on why your AC unit is freezing up. We look forward to assisting you with your home comfort needs.