Environmental Code of Practice for the Elimination of Fluorocarbon Emissions from Refrigeration and Air Conditioning Systems
The term “cooling” is used throughout the document and refers to both refrigeration and air conditioning.
Siting can have a significant impact on the performance of cooling systems, including reducing the potential for refrigerant releases.
Factors to consider when installing a cooling system:
- Accessibility of all indoor and outdoor components of the cooling system, including electrical outlets associated with the system.
- Keeping refrigerant lines as short as possible between indoor and outdoor units to minimize loss of cooling effect to the atmosphere. This could influence where mechanical rooms, chillers and other systems are located at a facility.
- Keeping the outdoor unit at a height above the indoor unit to prevent having to pump the refrigerant against gravity, which could reduce the efficiency of the system.
- Installing system components away from areas where noise could pose a problem. Variable speed drives can further reduce noise.
- Installing system components in a manner that prevents vibrations which would result in noise and/or stresses on the system.
- Shielding the system from weather conditions that could shorten its life or reduce its efficiency by making use of the natural environment (for example, using trees to create shade) or using a fence or a wall to protect the system from wind or snow.
- Providing adequate protection from debris, dust, moisture and physical damage.
- Identifying or labeling controls, switches and sensors.
- Affixing appropriate signs to the mechanical room (for example, for flammability).
- Installing a refrigerant alarm.
- Installing a refrigerant monitoring system in the mechanical room.
- Installing an emergency switch outside the mechanical room to cut off all electrical power when refrigerants that are flammable are used.
- Locating the system at a suitable distance from electrical devices, such as switches and relays, that may generate sparks.
- Installing a grounding system if applicable. Venting air purge outdoors.
- Allowing proper airflow and adequate ventilation in the area surrounding the system.
- Providing appropriate lighting in the area surrounding the system.
In order to prolong the system's life, enhance its efficiency, prevent leaks and ensure a safe environment, all system components need to be compatible. For example, mineral oil is not generally used with hydrofluorocarbons (HFCs); explosion-proof electrical components may be needed when using a refrigerant that is flammable.
Factors to consider when installing or servicing a system:
- Compatibility of the refrigerant, oil and the system, as well as the compatibility of the materials of the various system components.
- Characteristics of the fluid used in the system may cause scaling, corrosion or erosion failure. Careful selection of tubes, valves, and evaporator and condenser materials can help minimize catalytic corrosion. When a system contains non-ferrous materials, sacrificial anodes can be used to reduce corrosion pitting. Sacrificial anodes are effective only when the water is flowing through the system.
- Corrosion protection to prevent rusting of steel components.
- Air and moisture can cause acid generation and oil breakdown; attention must be given to material selection and the environment where the system will be located.
3.3 Selection of a Refrigeration and Air Conditioning System and its Components
The selection of a system can make a difference on the overall environmental performance. Certain components are integrated at the design phase, while others are installed on site. In addition to considering the cooling needs of the facility and the requirements in the applicable jurisdiction, contemplate choosing a system with the following components or adding them at the time of installation or service:
- Filter-dryer appropriately sized with the following properties:
- filter to remove particulate matter,
- desiccant to remove moisture and acid,
- isolation valves and refrigerant recovery connections to allow for servicing.
- Strainer or strainers-driers to capture solid contaminants.
- Compressor with a sight glass to indicate oil level.
- Valves allowing isolation of major components of the system in order to minimize the risk of refrigerant loss during servicing.
- Self-reseating relief valve to release pressure and avoid damage to the system.
- High-efficiency air purge system.
The way each component is attached will influence the system's performance. Because leaks often occur at connection, it is important to carefully assemble system components to prevent releases to the environment.
The following are best practices regarding the system assembly:
- Installing the system and its components, including tubing and pipe diameters, bend radii and lengths, and all connections, in accordance with the manufacturer's specifications and current regulations.
- Installing the system in such a manner as to minimize the number of fittings and connections.
- Providing adequate protection of piping and piping connections against external abrasion due to movement.
- Providing adequate support of piping connections to avoid stresses on the system.
- Planning allowances for expansion and contraction, especially at anchors and bends. Insulated hangers could be used for non-ferrous pipe.
- Connecting certain components to the system via flexible fittings so that vibrations are absorbed.
- Labeling the system and its components. The labels should be permanent, weatherproof and displayed prominently. Information could include the following:
- system manufacturer,
- refrigerant type and quantity,
- American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) refrigerant number,
- ASHRAE/Workplace Hazardous Material Information System (WHMIS) safety designation,
- oil type.
- Insulating pipes to prevent heat gain and condensation.
- Utilizing strainers or strainers-driers to capture solid contaminants.
- Deburring and removing metal filings from all cut pipes to prevent damage to the system's components.
- Cleaning all tubes and fittings prior to assembly.
- Ensuring that filler metal is compatible with the types of materials being joined when brazing and soldering.
- Using a lubricant for some compression fittings.
- Using these preferred methods of connections:
- welding or brazing for pipe sizes greater than 19 mm (3/4") outside diameter;
- compression-type fittings for small pipe sizes.
- Welding or brazing in new systems instead of using threaded connections.
- Adding vibration eliminators.
A valve is a pipe fitting that regulates, directs or controls the flow of a fluid by opening, closing or partially obstructing various passageways. The following are best practices regarding valves:
- Install isolation valves to facilitate servicing on all major components of the cooling system (for example, at the suction and discharge sides of a compressor).
- Use valves to protect gauges from pressure surges and to permit removal of these devices for repair or calibration.
- Mount the compressor on the system's frame in such a way as to prevent vibration and minimize stress on piping connections, including valves.
- Ensure that the compressor is accessible for leak testing and service.
- Date modified: