You would think that with an air conditioning system, freezing would be a good thing and would produce cold air. Sadly, this is not the case. An A/C works through a refined control of temperature level, pressure, and airflow. If any of these things fall out of balance, the refrigerant system that develops the cold air can overclock and freeze itself, without really making your air any chillier. A frozen air conditioning system will either blow warm or cool air or absolutely nothing at all. Of course, you’re questioning why this might be true and we’re here to explore what causes an AC unit to freeze.
How Your Air Conditioner Makes Cold Air
The key element In an air conditioner is the coil loaded with very cold refrigerant. When triggered, the refrigerant needs warm air to blow across them. This cools your air and keeps the coils warm enough so that they do not freeze over. On a straight cool system, your indoor coil gets rid of heat from the inside and transfers it utilizing the refrigerant to the outdoor coil. This presses the heat to the outside of the air conditioning unit. This is why your outdoor system feels like it’s blowing noticeably hot air since the system is pulling heat from your indoor air and transferring the additional heat outside.
It does this by controlling pressure through the refrigerant circuit. However, if something stops the warm air from blowing over the coils, or if the pressure is wrong inside the coils, then they can become too cold and can quickly freeze up. The reasons that the inside of your AC can become a frozen-up icebox relate to either airflow, pressure, or both. Let’s simplify cause-by-cause.
Wetness Makes It Worse
When humidity is high in the air, this only makes the freezing issue worse, as the ice starts to form on the coils. The ice insulates them with cold air so that any available warm air can’t reach the coils to warm them. The more wetness there is in the air, the more ice develops. It covers the inside of the AC like an old chest freezer and crawls up the copper pipelines.
Lack Of Airflow
The most common reason why your air conditioning can freeze up is a lack of airflow. This can be caused by a number of different breakdowns ranging from the blower motor to the air intake. If anything in the airflow system stops warm air from streaming over the coils while the compressor continues running, your A/C will begin to freeze up and this just worsens with time.
Your ducts are how air relocations through your house so if something blocks the duct, naturally air stops streaming correctly and this can block airflow to the coils. Even if the remainder of the system is running efficiently, a collapsed or blocked air duct in your house (or more than one duct) can trigger your Air Conditioner to lose airflow. The coils begin to freeze due to the fact that there’s not enough warm air to keep them at the optimum temperature.
Bad Blower Motor
The blower motor, naturally, matters a good deal in this system. Whether it’s the spinning motor itself or the blower motor’s run capacitor, if the blower fan stops blowing then the air stops streaming rapidly enough over the coils. And as soon as that air stops blowing, the coils begin freezing. You might hear irregular or rattling sounds from your Air Conditioner if your blower motor remains in the procedure of failing.
Clogged Air Filter
Last but not least, there’s your air intake filter. Your AC air filter is not something that must be casually disregarded, though it is all too simple to forget. That filter sits in between your dusty home vent and the Air Conditioner itself, keeping the air (and your compressor coils) clean. But when it fills up with dust, like any filter, it ends up being a blockage instead of a pathway. If your air filter is obstructed, it decreases airflow to a crawl and no amount of blower effectiveness can keep your coils from freezing.
What To Do If You Find Ice On Your Outdoor Unit
Finally, there’s what you can do if you observe your A/C blowing warm air and developing ice near the outside unit. If you see ice structure around or near any part of your A/C, your first step is to turn the thermostat off. This will shut off the compressor and enable the refrigerant to stop getting chillier. While the air conditioning is off, leave the fan on. Adding airflow can help to start melting the ice and lowering the issue.
Examine your air filter and alter it if it’s complete. A frozen air conditioner can be fixed, specifically if you switch off the compressor and call for service rapidly.
This post was written by Chad Merk, HVAC expert and owner of Florida Climate Worx! Providing quality HVAC services to the people of Tampa Bay for years now, our technicians pay great attention to detail when it comes to providing you with the best air conditioning repair in Clearwater! Our technicians pull out all the stops when it comes to providing you the best quality in the industry!