Tucson summers are some of the hottest we see across the states, with temperatures surpassing 100 degrees regularly from June to September. When these days arrive, the word “freezing” may sound appealing as you crank up the unit, hoping to find relief. However, the last thing you want is the AC unit needing to thaw out, leaving you asking, “What causes an air conditioner to freeze up in the first place?”

When your cooling system freezes, the hot and humid days leave you feeling sticky and lethargic. Rather than accept this fate, trust the best AC repair service in Tuscon, Arizona, to relay the top causes of this common AC unit issue and what you can do to resolve it.

What Does It Mean When Your Unit Freezes Up?

Your unit does more than get the shivers when it freezes up since you’ll notice HVAC system ice buildup on the evaporator coil within the inside portion of your air conditioner. Frost may also appear over the outdoor condenser coil in response to a frozen refrigerant line. But what does the formation of these ice crystals mean?

Poor Airflow

For the cooling process to work, the air conditioner sucks in warm household air and blows it over the refrigerant line, which is what the coolant travels within to absorb heat and leave only cool air behind. However, if no warm air is present in the indoor evaporator compartment or low airflow causes the cooled air to remain in the chamber, the coolant overcools, freezing in the refrigerant line.

Low temperatures also cause condensation, and the moisture eventually falls and freezes on the evaporator coil.

In most cases, poor airflow occurs due to clogged filters or dirty air ducts and vents. Frozen air conditioner solutions comprise cleaning or replacing your air filters every three to four months (or more frequently if you have allergies or live in an area with poor air quality). You should also call an expert for professional duct and vent cleaning so they can vacuum and repair the chutes for optimal air circulation.

Leaking Freon

Another of the air conditioner freezing causes include low Freon levels. Again, the sole purpose of refrigerant is to transfer heat, so if you have a diminished charge with an older unit or a leak that’s lowering Freon levels, it reduces pressure in the air conditioning system. Reduced pressure causes the indoor coil to drop below freezing temperature, leading to droplets turning to ice on the evaporator coil.

When this occurs, a specialist checks the Freon level and determines whether you need a recharge or a new unit altogether. They’ll also look for the leak, which is usually obvious, and fix it. That not only helps when preventing AC freeze-ups but also eliminates the health risk factor since the refrigerant is toxic with prolonged exposure.

Condenser Drain Clogs

Filter clogs are not the only blockages that’ll have you wondering, “What causes an air conditioner to freeze up?” Condenser drain clogs are one of the leading AC unit frosting reasons.

A condenser drain is a PVC or copper pipe that moves standing water from your unit to the area directly outside your home. Because temperatures fluctuate constantly in the system during the heat transfer process, the hot air that moves to the outdoor unit for discharging causes high humidity. As the air cools, moisture develops and collects in the drain pan that connects to the condenser drain line.

The drain line then expels water from the outdoor condenser compartment, but clogs keep the water stagnant within the system, allowing it to freeze during the next cooling cycle. Bacterial and fungal growth, such as algae, mold, and mildew, usually cause clogs that pave the way for ice formation on the coils.

So, technicians check the pan for overflow issues and growth, cleaning it out before moving onto the drain line. After using a garden hose, wet vac, or plumber snake (depending on the extremity of the case) to clear away obstructing debris, they’ll pour clean water into it to test its draining capabilities. Then, they may clean the line by flushing it with a mild soapy or cleaning detergent mixture.

Keep Cool Without Receiving the Cold Shoulder!

When you value a cooler indoor controlled climate but don’t want your unit to freeze in the process, it’s best to understand the common AC freezing triggers. Our #1, family-owned and operated Platinum Air Heating & Cooling can answer, “What causes an air conditioner to freeze up?” We’ll also explain other common air conditioning problems when you call (520) 867-9861!