Talking About HVAC

Posted on: 28 February 2023

Your air conditioning system's refrigerant is much different from other fluids you may be used to dealing with, such as the coolant or oil in your car. Unlike these other fluids, refrigerant won't produce noticeable puddles or obvious signs when it leaks. Air conditioning refrigerants will typically vaporize as they leave the refrigerant lines, quickly vanishing without a trace.

Because of how pressure works inside your air conditioning system, there's also no easy way for a homeowner to check refrigerant levels. Instead, you must rely on some typical warning signs to understand when there may be a leak. If any of these three symptoms appear with your air conditioning system, it's time to contact an HVAC contractor immediately.

1. Severe Freezing

If you're unfamiliar with fundamental thermodynamic behavior, you might find it surprising that a lower refrigerant pressure will produce colder temperatures at the evaporator coil. Your AC system relies on this behavior, using a metering device to reduce how much refrigerant enters the evaporator. However, too little pressure can result in colder-than-intended temperatures.

This condition causes condensate to freeze on the coil, insulating it and reducing efficiency. Minor refrigerant leaks may only cause your coil to freeze under heavy loads, but major leaks can cause rapid and severe freezing. If your coils quickly freeze up, your compressor is likely in danger, and it's critical to stop using your system and repair the leak.

2. Noticeably Higher Humidity Levels

As your evaporator coil absorbs heat energy from the surrounding air, the air's ability to retain moisture will fall, and condensation will form on the coils. This side effect is highly beneficial since it removes humidity from the air. As long as your air conditioner is running, it actively reduces humidity in your home and further increases comfort.

However, ice on the coil can negate this effect, sometimes even increasing humidity levels. If you notice cold, humid air from your vents, that's a relatively good sign that your coil is beginning to freeze up. This symptom can often occur before the coil completely freezes, so it's a good warning that it's time to take action before the situation becomes critical.

3. Compressor Thumps or Bangs

If you hear your compressor making a loud bang as it engages, stop using your system and call a qualified HVAC technician. While there may be a few causes for a noisy compressor, slugging is one potential reason. Slugging occurs when liquid refrigerant returns to the compressor, potentially washing away lubricating oil or causing severe internal damage.

In most cases, you'll only reach this stage if you've been running your system with a frozen evaporator coil for too long. Since the coils can no longer absorb heat, the refrigerant will be more likely to remain in liquid form. This situation can potentially destroy your compressor, so you should stop using the system and call for professional help.

Contact an AC repair contractor to learn more.