system where refrigeration is created by evaporating a refrigerant in a heat exchanger (evaporator) with the vapor then absorbed by an absorbent medium from which it is subsequently expelled by heating at a higher partial vapor pressure (in a generator) and condensed by cooling in another heat exchanger (condenser)
adsorption system
system that is designed to cool interior spaces through adsorption, a process that uses solid substances to attract to their surfaces molecules of gases or solutions with which they are in contact. Instead of using large amounts of electricity, the cooling process is driven by the evaporation and condensation of water.
accessories
optional parts added to equipment or system
access equipment
equipment used to allow mechanics to reach work location (e.g., ladder, scaffolds, personnel lift)
accumulator
vessel in the suction line that collects liquid refrigerant to be boiled off
analog controls
controls which are continuously variable between two points
building envelope
all the building components that separate the indoors from the outdoors, including the exterior walls, foundations, roof, windows, and doors
commission
final start-up activities before a system is fully functional that ensures the system meets design specifications and client requirements
component
parts required as part of a system
compressor
component that creates pressure differential in a system that allows a refrigerant to flow
computer room air conditioning (CRAC) unit
device that monitors and maintains the temperature, air distribution and humidity in a data center, network or server room. CRAC units replace the air-conditioning units used in the past to cool data centers. By comparison, CRAC systems have better air filtration, better humidity control mechanisms and higher airflow than typical AC systems
condenser
heat rejection component that provides a state change of refrigerant (from vapour to a liquid)
control system
electrical, electronic, mechanical and pneumatic components and wiring that are used to operate and protect the system
digital controls
control that use an on/off signal
district heating and cooling system
centralized facility for generation and distribution of the heating and cooling needs of a community, rather than individual heat or cold generators (i.e., furnace or air conditioner) at each residential, commercial, or institutional site
energy recovery ventilator (ERV)
type of heat recovery ventilator (HRV) that can exchange both heat and moisture
evacuation
removal of moisture, air and non-condensable gases from a refrigeration system
distribution
conveying means, such as ducts, pipes, and wires, to bring substances or energy from a source to the point of use. The distribution system includes auxiliary equipment such as fans, pumps and transformers
evaporative cooling
method of cooling air by using evaporating water
evaporator
heat absorption component that provides a state change of refrigerant (from liquid to a vapour)
field wiring
wiring required to be done on site
flow control
device for controlling the flow of primary and secondary refrigerants (e.g., crankcase pressure regulator [CPR], evaporator pressure regulator [EPR], solenoid valve)
fluid cooler
heat rejection device that cools a secondary heat transfer medium
heat exchanger
device used to transfer heat energy from one medium to another
heat pump system
thermodynamic heating/refrigerating system to transfer heat. The condenser and evaporator may change roles to transfer heat in either direction. By receiving the flow of air or other fluid, a heat pump is used to cool or heat. Heat pumps may be the air source with heat transfer between the indoor air stream to outdoor air or water source with heat transfer between the indoor air stream and a hydronic source (ground loop, evaporative cooler, cooling tower or domestic water)
heat reclaim equipment
equipment that uses heat taken from internal heat sources; applications are space heating, domestic or service water heating, air reheat in air conditioning, process heating in industrial applications, or other similar purposes
heat recovery ventilators (HRV)
ventilation device that captures heat from stale air leaving a building and uses it to preheat fresh air coming into the building. An HRV can reverse this process during the cooling season
holding charge
temporary or partial charge used for the protection of the system until commissioning
humidifier
device that introduces water vapour to conditioned space to raise relative humidity
humidity
measurement of moisture in air
internal wiring
wiring inside the system that includes factory and optional wiring
isolation
act of providing separation between 2 or more items, systems, areas, spaces, etc. Isolation is typically performed using an isolating device such as a disconnect switch, valve, damper or separate system
lock-out
isolating an energy source to ensure equipment is inoperable
maintain
performing functions to prevent premature deterioration and breakdown of system
material take-off
listing of material and components required for a project as taken from design drawings and job requirements
metering device
device designed to regulate flow of liquid refrigerant entering the evaporator
oil separator
device used to remove oil from refrigerant
predictive maintenance
monitoring system and components and analyzing operational data to assist in predicting performance of system and components and performing activities to prevent downtime or costly repairs. Some methods of predictive maintenance may include sensory inspection, vibration analysis, testing and maintenance of components
pressure control
pressure-activated safety or operational control
psychrometric
study of air and its thermodynamic properties, particularly regarding moisture mixed with air
receiver
storage vessel for liquid refrigerant
refrigerant
heat transfer medium used in a primary or secondary refrigeration system
refrigeration
transferring of heat from a place where it is not wanted to a place where it is required or unobjectionable
regulator
device that controls voltage or the pressure of liquid or gases
repair
fix system by repairing or replacing components and accessories
replace
change a component on a system
retrofit
process of upgrading systems either by replacing equipment, components, accessories, refrigerant and refrigerant oils, or by replacing entire systems. Retrofits are done to improve system performance and efficiency, and to comply with current industry standards and legislative requirements
sensory inspection
inspection done without tools using sight, smell, touch and sound
service
troubleshoot and repair system
solenoid valve
device that permits or stops liquid and gas flow
tag-out
labelling process that is always used when lock-out is required. The process of tagging out a system involves attaching or using an information tag or indicator
terminate
final connection of wiring or tubing to any device
trade standards
procedures based on codes, regulations, manufacturers’ recommendations and best practices
transducer
electronic device that sends a digital or analog signal to a control board
troubleshoot
diagnosing system failures and malfunctions
utilities
services such as electricity, drainage, water or gas provided by the city or utility companies
variable refrigerant flow (VRF)
engineered direct-expansion (DX) multi-split system incorporating at least one variable capacity compressor distributing refrigerant through a piping network to multiple indoor fan-coil units, each capable of individual zone temperature control, through integral zone temperature control devices and common communications network. Variable refrigerant flow utilizes three or more steps of control on common, interconnecting piping