Gas Trade: Unit 28 - Gas-fired air conditioning
CSA Group's 2019 Gas Trade materials reference the Red Seal Program's trade outlines for your preparation to become a nationally recognized gasfitter. Please visit the Red Seal Program's website for more details.
Gas technicians/fitters may be required to install or service equipment that uses the principles of absorption refrigeration. There are two general types of systems used:
• One uses ammonia and water in which the ammonia is the refrigerant and the water is the absorbent.
• The other uses water and lithium bromide in which the water is the refrigerant and the lithium bromide is the absorbent.
The ammonia-and-water solution is used in systems where refrigeration is involved, and the temperatures go below the freezing level. Ammonia freezes at -108°F (-78 °C). The lithium bromide/water system cannot be used for refrigeration as the water is the refrigerant and would freeze during the cycle. This type of system is used for air conditioning where the required temperatures are above the freezing point of water.
Gas technicians/fitters are not qualified to work on refrigeration and air conditioning systems as such. However, they are qualified to work on the burner systems that generate the heat to drive the system.
At the end of this unit you will be able to:
• Identify safety hazards associated with ammonia and lithium bromide;
• Explain the principles of refrigeration and cooling;
• Define key cooling and refrigeration terms;
• Describe the operation of an ammonia-water cooling system;
• Describe the operation of a water-lithium bromide system;
• Describe the operation of a gas-fired absorption chiller-heater unit; and
• List the installation and operational considerations for absorption chiller-heater units.
The Training materials have been revised to include the following changes throughout the training units:
▪ Updated language to enhance student understanding
▪ Revised references and links to the most current legislation
▪ Revisions include new technologies used in the industry
▪ Updated look and feel