5.9 Refrigerant Control

Refrigerant Control

General Control Principles

General refrigerant control consists of the plans, practices and procedures used to prevent or assist in preventing the release of refrigerants into the environment.

The following control principles, when applied, will reduce and in some instances eliminate refrigerant emissions.

Some general control principles include:

• Maintaining refrigerant charges within closed loop systems, pre-recharged components and refrigerant containers
• Reducing and where possible eliminating the discharging of refrigerants
• Replacing CFCs with HCFCs, HFCs or other alternative refrigerants to reduce their ODP to one that is more environmentally acceptable
• Reducing the expansion, contraction and vibration of refrigerant systems

The following are acceptable methods for controlling refrigerant emissions:

• Maintaining the Refrigerant Charge within the System
• Using Alternative Refrigerants
• Reducing Expansion, Contraction and  Vibration
• Leakage Control

Maintaining the Refrigerant Charge Within the System

When the refrigerant charge is maintained within its sealed vessel, whether that vessel be a refrigerant system, container or other component, it cannot be released into the atmosphere.

Refrigerant releases occur when systems are charged or refrigerant is transferred.

Some measures that may reduce the need to access the system or container are:

• Observe operating condition of refrigerant at the liquid line sight glasses
• Diagnose the system with temperature readings rather than pressure readings

Using Alternative Refrigerants

The use of alternative refrigerants will not reduce the total volume of refrigerant released.

They will, however, reduce environmental damage by utilizing alternative refrigerants with lower ODP’s.

Reducing Expansion, Contraction and Vibration

The expansion, contraction, and vibration of refrigerant lines and refrigerant equipment place stress on joints and fittings.

To reduce these stresses and the refrigerant leakage that can result, the following information and preventive measures should be considered.

Expansion and Contraction

Expansion and contraction occurs seasonally due to outdoor temperature extremes between summer and winter.

Operating temperatures and pressure differentials between the on and off cycles of refrigeration and air conditioning systems, plus the high coefficient of expansion of the copper refrigerant lines, result in additional stress on joints and fittings.

The effects can be neutralized by using any one or a combination of the following:

• Pipe supports that secure the location of the refrigerant lines and allow the refrigerant line to move
• Trombone bends
• Flexible piping connections

Vibration

Air conditioning and refrigerating equipment have many moving mechanical parts such as fans, motors and compressors.

As a result, refrigeration equipment experience a significant amount of vibration.

Leakage Control

Perform routine maintenance on equipment.

• This will locate leaks early and reduce refrigerant emissions that result from servicing of refrigeration equipment

Perform routine leak checks.

Always recover, reuse, recycle and reclaim refrigerant.

Keep gland seals lubricated.

Use brazed joints on refrigerant lines wherever and whenever possible.

On commercial systems, ensure the resettable relief valve is not set too low.

Always lubricate flared fittings with refrigerant oil for better tightness.

Use the least number of joints possible.

When checking for leaks only, use the approved leak test procedure.