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Thinking About Adding To Your Central A/C Yourself? Think Again

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If your central air conditioning system isn't cooling like it should, you're probably wondering if it's low on refrigerant. You might even be tempted to add extra refrigerant yourself -- after all, how hard can it be? A lot tougher than you think, as it turns out. There are plenty of good reasons why a DIY refrigerant charge could lead to more problems than it would possibly solve. The following explains why it's a bad idea for homeowners to attempt to add refrigerant on their own and why this task should be left to the professionals.

How Refrigerant Works

Refrigerant, also commonly known under the trademarked name "Freon," is a chemical compound that is capable of changing from liquid to vapor to gas at various pressures. The refrigerant cycles through a self-contained system consisting of a compressor, evaporator and condenser coils and expansion valve. During the refrigeration cycle, the refrigerant is used as a medium for absorbing and transporting latent heat away from indoor spaces and releasing it outdoors.

You Should Never Run Out of Refrigerant

Many homeowners mistakenly believe that their central A/C system's refrigerant will run out sooner or later. Unlike other fluids, your refrigerant won't evaporate or dissipate as long as it's kept in its self-contained system. As a result, you won't ever need to "top off" your refrigerant.

In fact, one of the only reasons your central A/C system will ever run low on refrigerant is because of a leak somewhere within the system. It's not uncommon for a pinhole to form somewhere along the refrigerant lines or within the evaporator or condenser coils. Failing gaskets and seals within the compressor or a leaky expansion valve can also cause refrigerant to escape.

The other possible reason is that your HVAC technician failed to add the proper amount of refrigerant to your central A/C system in the first place. The amount of refrigerant a typical central A/C unit needs depends on a variety of variables, including system size, SEER rating and evaporator coil size. In most cases, the manufacturer will have the correct amounts listed in the service manual or on the unit itself.

Without the right amount of refrigerant, your A/C system won't be able to cool your home properly. Low refrigerant levels may also cause long-term damage to the compressor and other parts of your A/C system.

You'll Need Specialized Tools

In addition to knowing how to handle your central A/C system, you also need plenty of specialized tools to actually add and recover refrigerant. For starters, you'll need high-pressure and low-pressure HVAC manifold gauges to properly measure refrigerant pressures, along with the appropriate hoses to connect to the central A/C system's refrigerant ports. Keep in mind that the refrigerant is under high pressure -- handling the system incorrectly could result in severe injury or worse.

Different A/C units also have specific charging procedures that must be followed to ensure good performance and minimize damage. For instance, you may be required to measure superheat and/or subcooling to ensure a proper refrigerant charge for your unit. Not following these procedures could result in damage to your A/C system.

You'll also need the proper type of refrigerant for your A/C system. Most modern units use R-410a, but others may use different types of refrigerant, some of which are incompatible with one another. Using the wrong refrigerant can also damage your A/C system.

Leave It to the Pros

Instead of putting your central A/C system at risk, you should have an experienced HVAC technician, such as those at McKinney Heating & Air Conditioning, inspect your A/C unit. If you think your A/C unit needs a recharge, your HVAC technician will first check for leaks and any other underlying issues that should be corrected first. Your HVAC technician also has the knowledge and expertise to safely handle the high-pressure refrigerant found in your A/C system.