If you notice warm air coming from your vents or if you see ice on your coolant coils, then you may have a refrigerant leak. This is also a possibility if you notice that your electric bills have increased substantially. The vast majority of leaks come can be found around the compressor and the coolant coils that sit inside the condenser unit. This means that leaks can be found outside your home. You can find the leak yourself by using the following advice.
Before You Begin
Before you start looking for an air conditioning refrigerant leak, you should investigate your system to see which type of coolant it holds. If your cooling system was installed before 2010, then it likely contains Freon. Refrigerant information will be listed on the nameplate attached to the outside cover of your AC condenser. Look for this to see if the refrigerant R-22 is listed. If so, then your AC unit contains Freon.
Freon can be dangerous if it comes into contact with the skin or if it is inhaled. While small amounts are typically harmless, the coolant is both colorless and odorless, so it can be difficult to tell if you are breathing in too much. You will need to watch out for symptoms of mild Freon poisoning that include headache, nausea, dizziness, and eye irritation. You also should wear rubber gloves before you start looking for a coolant leak. If your AC unit is in a more secluded corner of your home or if the condenser is surrounded by a fence, then add ventilation to the area while you work. An outside fan placed about five feet from the condenser is a good idea.
Simple Leak Detection
There are several methods you can use to detect a leak in your cooling system. The easiest and most cost-effective method is called the bubble test. Fill up a spray bottle with water and add two squirts of dish soap. Remove the screws from the top panel of the air conditioner and pull off the panel. Remove the exhaust fan from the top of the unit as well. Look inside the unit for a small black cylinder. This will be the compressor, and coolant lines will run to and from this part. Some coils may be attached to the metal fins that line the sides of the unit. Use your spray bottle and add a thick layer of your soapy fluid to the condenser and all the copper coils. Afterwards, look for bubbles that appear. The bubble will show you where the leak is.
Unfortunately, bubbles will typically only form when refrigerant leaks are fairly large. If smaller leaks are present, then the refrigerant will not release from the system with enough pressure to cause the soapy water to bubble up. If you do not see a bubble, then move on to more advanced leak detection.
Advanced Leak Inspection
More advanced leak detection can be completed with a dye that is injected into your HVAC system. This dye is a fluorescent material that will glow under UV light. You will need to purchase a leak detection kit from your local home store that includes the dye, a UV lamp or flashlight, and a connector hose. Look for a kit that includes the dye in a syringe so it is easy to add the fluid to the AC system.
Once you have the kit, look for a valve where you can add the dye to the system. There are two areas where it can be added. One valve is located by the control panel, and this is where refrigerant can be added to the system. Remove the control panel cover to find the valve connected to the coolant lines. The other access point is a refrigerant control valve, and it is located near the compressor pump. Once you find the valve you want to use, connect the hose attachment to it and squeeze the dye into the hose. Run your air conditioner for several minutes. Turn on the UV light and sweep it across all of the coolant lines to find the leak.
If you find the leak, contact your HVAC professional. A repair might be able to be made. However, it may be cheaper and more energy efficient to have a new unit installed. An AC professional from a company like Polar Air Heating and Cooling will be able to suggest the right course of action for your needs.