Your air conditioning system can't function without its refrigerant. More importantly, your system can't function without precise internal refrigerant pressure. Too much pressure can cause severe damage to your system and result in poor cooling, while too little pressure will cause temperatures at the evaporator coil to drop to dangerously cold levels.

Unfortunately, many homeowners mistakenly believe that their air conditioner's refrigerant is similar to the fluids in a car. In other words, it's a common misconception that you can check or top up your air conditioning refrigerant. In reality, you should never attempt to service your air conditioner's refrigerant without a professional, and here are three good reasons why that's the case.

1. Potential Refrigerant Loss

A typical residential air conditioning system features a service point that uses Schrader valves on the outdoor condenser unit. This service port allows technicians to attach a special gauge manifold to the system to measure its internal refrigerant pressure. These valves are similar to the valves on a tire. And, just like the valves on a tire, there can be some loss of refrigerant when making a connection.

However, unlike the tires on your car, a very small refrigerant loss may have a major impact on your system. If you don't know what you're doing or you're not careful, attempting to measure your refrigerant pressure can allow a significant amount of refrigerant to escape. Checking several times can greatly reduce your system's efficiency or cause damage.

2. Refrigerant System Contamination

Refrigerant loss isn't the only reason to fear those seemingly simple service ports. Your air conditioner doesn't feature any protection to stop external contaminants from entering the system at the service valves. Once you depress the valve core to make a connection, there's a potential for allowing contaminants into the system.

Experienced HVAC contractors know that it's important to make these connections only when necessary to minimize the potential for contamination. More importantly, keeping the tools and service ports as clean as possible is critical. Any mistakes can lead to moisture or particulate matter entering the refrigerant stream, likely leading to serious future issues.

3. Complex Diagnostics

Reading a manifold gauge set isn't nearly as simple as checking the oil on a dipstick. Your air conditioner's pressure will vary between the high and low sides and will change based on the system's current status and whether the compressor is running. As a result, interpreting the readings on a manifold gauge can be confusing for untrained do-it-yourselfers.

If you don't have a deep understanding of how refrigeration and air conditioning systems work, you can potentially make a problem much worse by misunderstanding your gauge's readings. If you suspect a problem with your system's refrigerant levels, it's always best to rely on a professional for a proper diagnosis and repair.

Speak to a local air conditioning service to find out more.