Welcome to the Comfort Zone Blog Ways to Help Prevent Frozen Air Conditioners Avoid Air Conditioner Meltdown There is nothing better than entering a nice cool house on a hot summer day. And few things are worse than sweltering in the heat as you wait for the HVAC technician to come fix your broken air conditioner, knowing it is going to cost hundreds of dollars to repair. The most common reason for a sudden air conditioner meltdown is frozen pipes and tubes. Why do Air Conditioners Freeze There are lots of things that can cause your AC unit to freeze. A qualified AC professional can help you find the source of the problem, but it does not hurt to understand how freezing occurs so you can take steps to prevent it. Refrigerant Charge: If your AC is running low on refrigerant or the fluid is improperly charged, the system can freeze. Leaks are a common cause of refrigerant problems; these can occur when moving parts rub together or vibrate over time. Leaks are also likely to be found where fittings and shoulder joints are loose.

Only a certified HVAC technician should check refrigerant levels and recharge the system if necessary. Airflow: Restricted airflow can cause the evaporative coils to get so dirty that they drop to a temperature below freezing. house a c unit freezing upHumidity in the surrounding air then collects and freezes around the coils. how to turn off air conditioning unitIf your air filters have not been changed in more than three months, airflow can be significantly reduced; air conditioning units average costundersized ducts are another common cause of poor airflow. Outdoor Temperature: Running your air conditioner on cool days can cause the unit to freeze up. Most central AC systems are not designed to work properly when outside temperatures dip below 60ºF.

How to Prevent Freezing Now that you understand the most common causes of air conditioner freezing, you can take positive steps to prevent problems in the future. Refrigerant Charge: To keep fluid levels functional, contact a qualified professional to perform a thorough test on your system. A technician will be able to look for leaks, repair damaged or weakened parts, refill coolant and make sure you AC is in good working condition. It is always a good idea to schedule maintenance before peak season to avoid high prices or emergency service charges. Airflow: Change the air filters regularly, usually about every three months or so. This is the simplest, most cost-effective way to ensure your air conditioner does not freeze. If you notice that the AC’s evaporative coils are already dirty, you will need to have them cleaned by a professional. You may be able to vacuum out some of the debris yourself, but some have coils that need to be removed for proper cleaning. Outdoor Temperature: This one is pretty simple;

just do not use your air conditioner when the outside temperature is below 60º. Not only will you prevent your system from freezing, but you will also save energy and money on utility costs by just opening the windows on cool days. So, when you are ready to install or replace your home’s air conditioner or heater system, please contact Horizon Services. Our friendly and experienced team of Home Comfort Consultants knows air conditioning and heating systems inside and out. Additional Information from Horizon Services…My Air Conditioner is Frozen! Save Energy by Unplugging Household Devices and Appliances 7 Things in Your House That Could Explode Horizon Air Conditioning Services Horizon Drain Cleaning Services Horizon Sewer & Water Line Replacement ServicesAir conditioners ice up when the cooling coil becomes colder than the dew point in the home. A window air conditioner can make a hot day much more bearable indoors. These units are designed to cool no more than one or two rooms, and they work best when the size of the unit fits the size of the room it's cooling.

Ice can form on the unit and stop it from cooling if the air conditioner is too large for the room or requires cleaning. Deicing the unit properly to avoid damage takes time, but performing some general cleaning afterward can prevent the problem from happening again. Turn the unit off immediately if the fan is no longer spinning. Continuing to run a frozen air conditioner can damage the unit if the fan has also frozen. Allow the unit to thaw naturally until water begins dripping freely before attempting to turn the fan on again. Turn the air conditioner to the fan-only setting if the fan isn't frozen or after it has begun to thaw. The warm air circulating through the unit can help thaw the frozen coils. Spread towels beneath the unit inside the home. As the air conditioner thaws, water will drain from the unit. Inspect the unit periodically for thawing. It can take an hour or longer for the unit to thaw depending on the extent of the freezing and whether the fan is able to run. Exchange the towels for dry ones if necessary.

Turn off the air conditioner after it has thawed sufficiently for you to access the filter. Remove the front panel of the air conditioner to reveal the filter. Remove the filter from the unit. Clean the filter with warm water and laundry detergent to remove the dust and other debris that could be blocking it. Rinse with clear water. Allow the filter to air-dry completely before replacing it in the unit. Examine the exterior of the unit. Remove any debris blocking the condenser coil vents on the outside of the air conditioner. Debris inside the coils requires complete disassembly and cleaning of the unit, which is best done by trained service professionals. Turn the unit on after it has thawed completely and the vents and filter are clean. Adjust the thermostat so the unit automatically shuts off when the room is at the desired temperature. Window units are less likely to ice over if they aren't left constantly running. Heat pumps can ice-up during the winter time. And it is normal for the entire coil to be covered in a white frost, even light ice, during certain weather conditions.

But it is not normal for the entire unit to be encased in ice; including the top of the unit and the insides of the coil for an extended period of time. This indicates a problem and should be addressed quickly to save energy and avoid serious damage to the equipment. Heat pumps will naturally ice-up in the winter but will periodically go into a defrost cycle to de-ice the coils. This keeps the unit running efficiently. If the coils are blocked by ice, proper heat transfer between the refrigerant and the outside air cannot occur. The unit pictured left, was iced-up so badly, it damaged the fan blades, crushed the outdoor coils; causing the refrigerant to leak out and ruined the compressor - a complete loss. On a call for defrost, the reversing valve is energized, switching the system into the air conditioning mode. That is right - Air Conditioning. The outdoor evaporator becomes the condenser but at the same time the outdoor fan shuts off. This allows the high pressure refrigerant circulating through the outdoor coil to get very warm, melting the ice.

At the same, the second stage heat (the back-up heat) is energized to offset or temper the cold air now blowing out the vents. When a sensor or thermostat in the outdoor unit reaches a certain temperature and/or a certain amount of time goes by, the system goes back to normal heating mode. At this time a cloud of water vapor can usually be seen rising out of the outdoor unit and a "whoosh" sound can be heard as the refrigerant reverses direction. The entire process usually takes between 2 to 10 minutes depending on conditions. Different heat pumps have different ways of determining when to go into defrost. Some (older models) use mechanical timers in conjunction with a defrost thermostat. If the thermostat is cold enough and enough time goes by, the unit will go into the defrost mode, whether it's iced-up or not. When the thermostat heats up to a certain temperature, defrost is terminated. Hopefully at this time, much of the frost has melted off. Most of the newer equipment today uses solid-state control modules with temperature sensors.

Even more sophisticated is the Demand Defrost system which makes calculations based on the outside air, the refrigerant temperature in the coil, and run time. This is the most efficient way to defrost. If a heat pump is severely iced-up during winter use, it's possible that it's not defrosting, but there are many other causes. Bad defrost control or timer Bad defrost thermostat or sensor Bad reversing valve solenoid coil Bad outdoor fan motor Outdoor coil blocked - possibly with leaves or snow drift Unit sunk in ground - nowhere for ice to melt and drain off Leaking gutter dripping water onto top of unit Freezing rain - causes top of unit to freeze over - once this happens the rest of the unit will also freeze over If the top of the heat pump is covered in ice, turn it off and remove the ice. If a gutter is dripping on the heat pump, repair the gutter. Keep snow and leaves away from the heat pump including underneath it. If the heat pump has settled into the ground, it must be elevated - usually on blocks or special feet.