Chillers Types and Terms
Chiller Types
- ,
the most common chiller type, require little maintenance. However,
because of the need for high condensing temperatures ranging from 120° F
to 140° F, air cooled chillers require more power to operate.
- consist of air handling units fitted with chilled water
coils and are utilized in air condition systems.
- are
used to remove heat from an area.
- operate
year-round and are designed to provide specific, capacity-matched cooling
protection and proper temperature/water flow. Dedicated-process chillers
are the best choice for medical applications.
- are uncommon but highly efficient liquid chillers.
Evaporative chillers maintain the lowest condensing temperatures,
which range from 85° F to 105° F.
- provide
process cooling using a secondary fluid.
- are
often installed outside and are available in centralized and modular
designs. HVAC chillers are used in industrial and commercial environments.
- are
refrigeration systems that are used to chill various liquids in industrial
settings.
- are
refrigeration systems that remove heat from various liquids.
- Liquid coolers are typically recirculating chiller systems which recycle the same refrigerant liquid within a closed loop.
- lower
the temperature of coolant that is used in the cutting zone and recirculate
it back to the machine tool in a closed-loop system.
- are
self-contained chillers with higher pressure pumping, temperature stability
and microprocessor controls.
- are
self-contained units and are useful in small and/or dedicated applications.
- constantly
circulate coolant in a closed loop, retaining high efficiency without
wasting water.
- consist
of a compressor, condenser and chiller with internal piping and controls
all contained within a single unit. The term "water chillers" refers
also to an overall package that includes a refrigeration plant, water
chiller and air or water cooled condenser.
Chiller Terms
- The surrounding environment, including
temperature, pressure and/or humidity, coming into contact with a system
or component.
- Mineralized water consisting of sodium chloride, metallic
and/or organic contaminants.
- A measurement unit reflecting the
amount of heat needed to change the temperature of one pound of water
one degree Fahrenheit.
- Tube located between the condenser and evaporator
that manages the refrigerant flow.
- A chilling system that is self-contained.
A central chilling system has more than one unit and more than one compressor
but no pump tank set.
- A gas consisting of chlorine,
fluorine and carbon that has been used as a refrigerant in such items
as liquid
chillers. CFCs cause ozone depletion, because they do not break down
upon release into the atmosphere, but mix with ultraviolet light to create
carbon dioxide, and eventually ozone-eating chlorine radicals.
- The
measurement of a refrigeration system's efficiency that compares
the system's cooling ability
with the heat input necessary to attain such cooling. COP is calculated
by dividing a system's cooling ability by the system's heat
input and is expressed in BTU/hr.
- A device that
increases pressure on a gas through the act of pumping. Compressors are
responsible for the compaction of
the vaporized refrigerant to a pressure level suitable for liquification,
which occurs in the condenser.
- A device that removes
heat via forced air, water coil, etc., in order to convert a high pressure
gas into a lower pressure liquid.
Condensers remove heat from the compressed vaporized refrigerant, at
which point, the refrigerant returns to a liquid state.
- The
central part of a refrigeration system in which the system is operated
and maintained.
- A liquid used to remove heat.
- Indicates
the efficiency of an air conditioner or cooling system by comparing the
amount of energy needed
to produce cooling with the quality of the system's cooling ability
and is calculated by dividing the system's BTU by its wattage.
For example, if a cooling system maintains 20,000 BTUs and uses 1,500
watts,
the system's energy efficient rating would equal 13.3.
- Consists of a tube inside which the refrigerant soaks
up heat from it surroundings, boils and changes to a vapor.
- Mechanism located between the evaporator and
condenser that controls the refrigerant flow into the evaporator and
controls the temperature of the evaporator.
- Removes moisture and contaminants from vaporized
refrigerants.
- A device that
transfers heat from one fluid to another without mixing the fluids. (www.heatexchangers.org)
- A substance containing
chlorine, fluorine, carbon and hydrogen that is used as an alternative
to CFCs
as a refrigerant and a propellant. HCFCs produce fewer effects on than
ozone layer than CFCs do.
- A substance containing hydrogen, fluorine
and carbon that is used to replace CFCs and HCFCs because of HFCs lack
of effect on the ozone layer. HFCs produce no ozone depletion because
the substance does not contain chlorine, which breaks down the ozone
layer.
- A process that utilizes light to cool atoms to
a very low temperature.
- A molecule containing three oxygen atoms that absorbs ultraviolet
radiation in the stratosphere. Ozone also remains a harmful component
of smog and can contribute to lung damage and respiratory problems.
- A relative measurement of a substance's
negative effect on the ozone layer as compared to the effects of CFC-11,
which has an ODP of 1, on the ozone. For instance, a substance with an
ODP of 2 can potentially cause approximately twice the ozone depletion
as CFC-11 could.
- Also referred
to as the stratospheric ozone, it is the protective atmospheric layer
in the stratosphere, located 12-30
miles (20-50 kilometers) above sea level, in which ultraviolet radiation
is absorbed.
- The storage area for condensed liquid refrigerants.
- Liquids that produce cooling upon evaporation.
- Unit equal to 12,000 BTUs that refers to the
size of the chiller unit.
- A window in a refrigeration system through which
specialists can view the inner workings of the system.
- Mechanism
in a refrigeration system that controls the flow of refrigerant, especially
into the expansion valve.
- The
total amount of carbon dioxide that a refrigeration system can produce
throughout its lifetime.