20. December 2017
We’ll cut to the quick: Yes, something is wrong with your central air conditioning system if you notice ice forming on its coil. If this was your first instinct, then you’re thinking along the right lines. People often dismiss the appearance of ice on an air conditioner as a sign that the system is perhaps working a bit too well. The air coming out of the AC is cool, so why wouldn’t ice be part of the process?
But as you may already know, an air conditioner doesn’t use ice to cool down the air it sends into a home. What it actually does is remove heat from inside the house and release it outside, a process called heat exchange. If the air conditioner is working correctly, no ice should develop during this absorption and release of heat.
So what does it mean when ice starts to appear?
It can indicate a number of different problems with the air conditioner, ranging from minor to major. One thing is certain: you’ll need HVAC technicians to help you and find the root problem. They’ll also have to take care of the job of defrosting the ice of the coil to restore the system to its regular function. Don’t try to chip or scrape off the ice yourself! Not only does this not address the cause of the ice forming, but it can potentially cause damage to the coil.
Here are some of the possible sources of ice on the AC coil:
- Clogged air filter: The HVAC system air filter needs routine changing during the year, usually every 1 to 3 months. If the filter becomes clogged, not enough warm air will flow into the AC and over the evaporator coil. The cold refrigerant in the coil won’t warm up, leading to moisture along the coil to freeze.
- Dirt and grime on the coil: If too much dust and other debris is allowed to get inside the AC cabinet (which can also occur because of a clogged filter), it can create a layer of grime across the coil. This will insulate the coil, making it harder for it to draw heat from the air, which in turn will keep the coil too cold.
- Loss of refrigerant: This seems to be the reverse of what you’d expect. How can less refrigerant mean the coil stays too cold? The reason is that when there’s not enough refrigerant to absorb sufficient heat to warm it up, the remaining refrigerant will stay cold, triggering ice development.
No matter the cause, ice developing on the coil will create more ice because it blocks further heat exchange. Eventually, enough ice will develop to block any heat absorption, and it can also cause the coil to start to warp. Never delay with calling HVAC technicians for help, especially since the ice may mean a loss of refrigerant—a serious situation that can cause the AC to break down.