air conditioning services
heating services

Refrigerant Loss

Adding Freon to a Low System

It is important to understand that an air conditioning or refrigeration system is a “sealed system". This means that refrigerant (otherwise known as Freon), should never leak out.

There are two main types of systems, one that is packaged and charged at the factory, for example your refrigerator, and another a “Split System”, one that is installed and connected with copper tubing in the field, such as a typical air conditioning or heat pump system.

This “split system” requires a technician to adjust/add refrigerant charge when commissioning the system. This can be done in a few different ways. There are several methods used to determine system charge, such as super heat/sub cooling/approach methods. The most accurate method is by weight. Using the “weight” method, the system has to be either void of all refrigerant, or must be new with service valves unopened so the factory charge is predetermined. With this said, it is entirely possible that the field technician did not properly charge the system when commissioning the system, which could affect system performance and efficiency. This case however is usually not suspect when we find very low system pressures.

The important thing to understand is that if a system is low, there are two choices. Simply add Freon to the system in an effort to provide immediate cooling relief, or identify and seal the source of the leak. It is important to note that the leak could be in the indoor section, outdoor section, or the copper tubing connecting the two. And there is no guarantee that the leak is the only one. There may be multiple leaks.

There are a few reasons why leaks occur. They have been linked to the effects of salt at seaside locations, the building envelope and use of household chemicals. It should be noted that every major manufacturer has experienced leak issues associated with the coil manufacturing process and this has been an industry wide problem.

Leak checking can be accomplished in a few different ways, one is to “sniff” for it with a refrigerant leak detector, another is to listen for it with an ultrasonic leak detector, and yet another is to inject a dye which can be seen with a UV light. We do not use this last method because it can void some compressor warranties.
It must be noted that finding a leak can be a trying task. Some leaks are large and easily identified, where others are so small that they can be virtually undetectable. In some cases the only way to determine which component is leaking is to disconnect and isolate all three components i.e. outdoor unit, indoor unit, and connecting tubing. In this case it is labor intensive, and costly. This involves pressure testing with nitrogen, and possible making a return trip to determine which component has lost pressure, then taking the necessary corrective action.

With all this said, there are products that claim to seal small leaks, and we have added this when requested. It should be noted that larger leaks do not seal well. The decision to use this product is at the sole discretion of the consumer.

Our Policy:
It is important that you are informed. If the consumer elects to add a leak sealant, or simply add Freon to their system, the risk is entirely theirs. We are happy to take whatever action you choose, but will not refund, reimburse, or otherwise provide compensation for repeat leaks, or additional service that may be necessary.

Hours of Operation

Mon - Fri :
8:00AM - 4:30PM
Sat & Sun :
Emergencies : Call for Service

Contact Info

Phone :
Fax :
Email :


150 Airport Drive Unit 1
Westminster, MD 21157

  • Office Location
  • Check out our FAQ Section for Frequently Asked Questions

    Read our York Extended Warranty Agreement


    Home | About | Services | Testimonials | FAQs | Indoor Air Quality | Contact | Site Map