Understanding Leaks in the Summer Around the HVAC Unit: The Role of the AC Drip Pan

As the summer heat sets in and the mercury reaches triple digits in the Houston area, your HVAC system becomes a lifeline for maintaining a comfortable indoor environment.

However, it's not uncommon for issues to arise, such as leaks around the HVAC unit, especially around the AC drip pan or drain pain, and condensation drain lines running from the inside equipment.

Now, do not be ashamed if you are asking yourself: “Wait, I thought my AC unit was all about air … where does the water come from?”

“Unless you’re an experienced HVACR (heating, ventilation, air conditioning, and refrigeration) professional, most people don’t realize that air conditioning, refrigeration, and other HVACR equipment can produce condensate during normal operation,” says The Air Conditioning Contractors of America “Ultimate Guide to HVAC Condensate”.

In fact, a normal operating AC system can create anywhere between 5 and 20 gallons of condensation per day that needs to be drained.

According to the guide, you should be aware of the following:

• All air conditioning systems produce condensation during normal operation.
  
  
• Condensate must be drained or pumped from systems to avoid costly damage.
  
  
• Condensate pumps, drain pans, and drain lines require routine maintenance.
  
  
• Condensate overflow and leaks can cause water damage, mold growth, and unpleasant odors.
  
  
• Some condensate is corrosive and requires treatment.
  
  

The AC Drip Pan: Why It's Needed and How HVAC Units Work

HVAC units consist of condensation coils that cool the air by removing moisture from it.

“Condensate is created during a change in the state of water from a gas or vapor form into a liquid form. It generally occurs when vapor in warm air encounters a cool surface, which normally occurs in air conditioning systems, refrigeration equipment, and other types of cooling and heating equipment,” says the Ultimate Guide HVAC Condensate.

This condensation needs to be collected and drained to prevent damage to the system and your home. The AC drip pan, also known as the “condensate pan” or “AC drain pan”, is a crucial component that captures the moisture produced during the cooling process.

When warm air passes over the cold evaporator coils, condensation occurs, and droplets of water form. The AC drip pan collects this water -- to prevent it from damaging the HVAC system or causing water-related issues within your home – which then drains through a condensate drain line.

While some HVAC setups include a main condensation line that drains directly from a pipe outside the house, other systems have the drain line running from the evaporator to a plumbing trap, commonly referred to as a "P trap."

A plumbing trap is a curved pipe that retains water to prevent sewer gases from entering your home. These traps are usually found under sinks in bathrooms and kitchens, but they can also be in other areas where plumbing fixtures are present, such as utility rooms or laundry areas.

The Secondary Condensate Line and Its Importance

The secondary condensate line is an additional safeguard if the main condensate drain clogs or overflows. This second line is a backup or emergency line and will often include a drip pan in a visible location under and around the HVAC equipment.

The secondary condensate line typically drains outside the home, at a higher elevation than the lower part of the system. This ensures that any water collected in the AC drip pan is directed away from the building and doesn't cause water damage or flooding.

While you want to see water dripping from the primary condensate line during AC operations, you do not want to see what dripping into a secondary or emergency AC drip pan – this is a sign that your primary line is clogged or not working properly, or water is leaking from other parts of your equipment and being collected.

In some cases, this AC drip pan may have a float valve installed. If water reaches a certain level, the float valve shuts off the HVAC system to prevent leaks and damage to the surrounding area.

“Because primary drain pans are often difficult to access, a secondary drain pan can be a useful indicator of an overfilled primary pan. These pans can also save technicians and homeowners from dealing with the major headaches that can come from a plugged-up primary drain line,” says Budget Air Supply and Equipment.

Houston, We Have a Problem: AC Clogs and Leaks

The main condensate or secondary condensate lines can become clogged or develop leaks due to various factors, including dirt, debris, algae growth, or even improper installation.

A clogged line can lead to water backing up into the system, potentially causing significant damage to the HVAC unit, walls, floors, and ceilings.

Water damage from condensate line issues can result in costly repairs and create an environment conducive to mold growth, posing health risks to you and your family. It's important to address clogs or leaks promptly to mitigate potential damage and prevent further complications.

These drain lines are designed to last for many years, but like any component, they may eventually deteriorate or develop issues over time. Regular maintenance and inspections are essential to identify and resolve any potential problems before they escalate.

The Ultimate Guide to HVAC Condensate says these are some common issues with condensate water in HVAC systems:

• Condensate Drain Pan Problems: AC drip pans or drain pans can corrode or crack after use, leading to water leaks which can damage your HVAC system and home.
  
  
• Clogged or Dislodged Drain Line: Fungus and bacteria build-up in a condensate drain line can clog it, often leading to the entire line being dislodged and cause damage by the overflowing water.
  
  
• Broken Condensate Pump: Some systems have automatic condensate pumps to assist in the removal of water from the system and these pumps can malfunction if not maintained properly or if they become plugged. This will lead to water leaks in the home.
  
  
• Dirty Air Filter: If your system has a dirty air filter, it can restrict adequate airflow over the evaporator coil. Without proper airflow, the coils can get too cold and freeze. When this ice melts, it can lead to an overflowing AC drip pan.

“Properly designed and maintained systems should easily drain the condensate via a gravity drain line or an automatic condensate removal pump. However, problems and damage can occur when condensate overflows or leaks occur due to lack of maintenance or equipment failure,” says the guide.

While HVAC specialists are experts in maintaining and repairing HVAC systems, plumbers play a crucial role in addressing clogged condensate lines or leaks, particularly when they involve the P trap.

Plumbers have the necessary skills and expertise to inspect, clean, and repair plumbing traps. They can remove clogs, eliminate debris, and ensure proper water flow through the system.

By collaborating with HVAC specialists and a trusted licensed plumber, you can ensure a comprehensive approach to resolving any issues related to your AC system and keep your cool all summer.