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REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT-PUMP SYSTEMS ( { evaporation or evaporation apparatus for physical or chemical purposes, e.g. evaporation of liquids for gas phase reactions B01B 1/005} ; heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants, or materials for the production of heat or cold by chemical reactions other than by combustion C09K 5/00; pumps, compressors F04; use of heat-pumps for domestic- or space-heating or for domestic hot-water supply F24D; air-conditioning, air-humidification F24F; fluid heaters using heat pumps F24H)
Definition statement
This subclass/group covers:

Refrigeration machines, plants or systems; combined heating and refrigeration systems; heat-pump systems.

Cold production at temperatures below ambient, not transportation of heat.

Relationship between large subject matter areas
Evaporation or evaporation apparatus for physical or chemical purposes, e.g. evaporation of liquids for gas phase reactions:
Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants, or materials for the production of heat or cold by chemical reactions other than by combustion:
Pumps, compressors:
Use of heat-pumps for domestic- or space-heating or for domestic hot-water supply:
Air-conditioning, air-humidification:
Fluid heaters using heat pumps:
Informative references
Attention is drawn to the following places, which may be of interest for search:
Cooling of a manufacturing process
Arrangements or adaptations of heating, cooling, ventilating or other air-treating devices specially for passenger or goods spaces of vehicles
Air plane air-conditioning
Mechanical-power-producing mechanisms
Piston compressors
Rotary compressors
Centrifugal compressors
Valves
Liquefaction, solidification, or separation of gases or gaseous mixtures by pressure and cold treatment
Details of heat-exchange or heat-transfer apparatus, of general application
Cooling of personal computers
Cooling of superconducting magnets
Modifications to facilitate cooling, ventilating or heating of different types of electric apparatus
Special rules of classification within this subclass

When classifying heat pump circuits or systems, groups F25B 1/00 to F25B 25/00 and F25B 29/00 take precedence over group F25B 30/00.

Classification in F25B when refrigeration cycle of air-conditioner is claimed, except for reheat circuits: circulate to F24F 3/153.

F24F, when focus is on air side of refrigeration cycle.

B60H, when focus on refrigeration cycle is specific for a car (e.g. car speed, sunlight).

F24D 11/00, when focus is on heat water/heating heat pumps.

F25D, when a cold room is cooled.

Compression machines, plant, or systems with non-reversible cycle (F25B 3/00, F25B 5/00, F25B 6/00, F25B 7/00, F25B 9/00 take precedence)
Definition statement
This subclass/group covers:

Compression machines, plant, or systems with non-reversible cycle

Special rules of classification within this group
with compressor of rotary type ( {F25B 1/005,} F25B 1/10 take precedence)
Special rules of classification within this group

F25B 1/005, F25B 1/10 take precedence.

with compressor of jet type, e.g. using liquid under pressure ( {F25B 1/005,} F25B 1/10 take precedence)
Definition statement
This subclass/group covers:

Ejectors operating as compressor.

References relevant to classification in this group
This subclass/group does not cover:
Ejectors used as expansion device
Special rules of classification within this group

F25B 1/005, F25B 1/10 take precedence.

Compression machines, plant, or systems, with several evaporator circuits, e.g. for varying refrigerating capacity (with cascade operation F25B 7/00)
References relevant to classification in this group
This subclass/group does not cover:
Compression machines, plant, or systems with reversible cycle
With cascade operation
Informative references
Attention is drawn to the following places, which may be of interest for search:
Multi-stage operation
Special rules of classification within this group

The refrigerant flow determines if the evaporators are in series or in parallel, not the air flow.

F25B 5/00 classification of documents having parallel and series evaporators combined in one embodiment.

F25B 5/02 classification of documents having only evaporators in parallel in one document.

F25B 5/04 classification of documents having only evaporators in series in one document.

Documents combining embodiments with only evaporators in parallel with embodiments with only evaporators in series should be classified in F25B 5/02 and F25B 5/04/CCA or F25B 5/04 and F25B 5/02/CCA.

Evaporators exchanging heat at different pressure levels are additionally classified in F25B 1/10/CCA.

Compression machines, plant, or systems, with several condenser circuits
References relevant to classification in this group
This subclass/group does not cover:
Compression machines, plant, or systems with reversible cycle
Special rules of classification within this group

The refrigerant flow determines if the condensers are in series or in parallel, not the air flow.

F25B 6/00 classification of documents having parallel and series condensers combined in one embodiment.

F25B 6/02 classification of documents having only condensers in parallel in one document.

F25B 6/04 classification of documents having only condensers in series in one document.

Documents combining embodiments with only condensers in parallel with embodiments with only condensers in series should be classified in F25B 6/02 and F25B 6/04/CCA or F25B 6/04 and F25B 6/02/CCA.

Compression machines, plant, or systems, with cascade operation, i.e. with two or more circuits, the heat from the condenser of one circuit being absorbed by the evaporator of the next circuit (F25B 9/00 takes precedence)
References relevant to classification in this group
This subclass/group does not cover:
Primary and secondary systems
Special rules of classification within this group

F25B 9/00 takes precedence.

Compression machines, plant, or systems, in which the refrigerant is air or other gas of low boiling point
Informative references
Attention is drawn to the following places, which may be of interest for search:
Refrigerants
Arrangement or mounting of refrigeration units with respect to device
Thermal coupling structure or interface
{the refrigerant containing more than one component (F25B 9/004 takes precedence; refrigerant materials per se C09K 5/00) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Special arrangements or features of compression machines, plant or systems characterised by the refrigerant being carbon dioxide
Special arrangements or features of compression machines, plant or systems characterised by the refrigerant being carbon dioxide with the cycle highest pressure above the supercritical pressure
Special rules of classification within this group

Special arrangements or features of compression machines, plant or systems characterised by the refrigerant being carbon dioxide are additionally classified in F25B 2309/06 and F25B 2309/061 when the cycle highest pressure is above the supercritical pressure.

using expanders (F25B 9/10 takes precedence)
Special rules of classification within this group

F25B 9/10 takes precedence, however in case of multi-stage expander classify also in F25B 9/06/CCA. Only gas cycle and CO2 expanders are classified in F25B 9/06, other expanders are classified in F25B 11/02 or in F25B 2400/14

using ejectors (F25B 9/10 takes precedence)
Special rules of classification within this group

F25B 9/10 takes precedence, however in case of multi-stage ejector classify also in F25B 9/06/CCA.

characterised by the cycle used, e.g. Stirling cycle { (engine plants with Vuilleumier-type cycles F02G 1/0445) }
References relevant to classification in this group
This subclass/group does not cover:
Stirling motors
Engine plants with Vuilleumier-type cycles
Informative references
Attention is drawn to the following places, which may be of interest for search:
Special arrangements or features of Ericsson cycles
Control of a Stirling refrigeration machine
Special rules of classification within this group

Special arrangements or features of Ericsson cycles are additionally classified in F25B 2309/1401.

Control of Stirling refrigeration machines is classified in F25B 2309/1428.

{pulse-tube cycle}
References relevant to classification in this group
This subclass/group does not cover:
Thermoacoustic engines
Informative references
Attention is drawn to the following places, which may be of interest for search:
Special arrangements or features of pulse-tube cycles
Special rules of classification within this group

Special arrangements or features of pulse -tube cycles are additionally classified in F25B 2309/1402 and lower.

Compression machines, plant, or systems, using turbines, e.g. gas turbines
Definition statement
This subclass/group covers:

Compression machines, plant, or systems, using turbines, e.g. gas turbines.

Special rules of classification within this group

With CO2 as refrigerant classify in F25B 9/06.

Compression machines, plant, or systems withreversible cycle (defrosting cycles F25B 47/02)
Definition statement
This subclass/group covers:

Compression machines, plant, or systems with reversible cycle: both condenser and evaporator change function when reversing the reversing valve.

References relevant to classification in this group
This subclass/group does not cover:
Defrosting cycles:
Informative references
Attention is drawn to the following places, which may be of interest for search:
Special arrangements or features of compression machines, plant, or systems with reversible cycle not otherwise provided for
Special rules of classification within this group

Special arrangements or features of compression machines, plant, or systems with reversible cycle not otherwise provided for are additionally classified in F25B 2313/00.

Sorption machines, plant, or systems, operating continuously, e.g. absorption type
Definition statement
This subclass/group covers:

Sorption machines, plant, or systems, operating continuously, e.g. absorption type. A refrigeration system in which the process is as follows:

vaporization of the refrigerant; absorption of the vapour by an absorbing liquid; extraction of the refrigerant vapour by heating this liquid; condensation of the refrigerant; expansion of the refrigerant.

References relevant to classification in this group
This subclass/group does not cover:
Sorption machines, plant, or systems, operating intermittently
Informative references
Attention is drawn to the following places, which may be of interest for search:
Boilers, Analysers, Rectifiers
Boiler-absorbers, i.e. boilers usable for absorption or adsorption
Absorbers, Adsorbers
Special arrangements or features of sorption refrigeration cycles
Special rules of classification within this group

Special arrangements or features of sorption refrigeration cycles are additionally classified in F25B 2315/00.

with inert gas ( {F25B 15/004, F25B 15/006, F25B 15/008} , F25B 15/12, F25B 15/14, F25B 15/16 take precedence)
Definition statement
This subclass/group covers:

Absorption systems which, in addition to refrigerant and absorbent, also employs an inert medium (such as hydrogen) in order to balance pressure in the various parts of the refrigerating circuit

Informative references
Attention is drawn to the following places, which may be of interest for search:
Special arrangements or features of inert heat-exchangers
Special rules of classification within this group

Special arrangements or features of inert heat-exchangersare additionally classified in F25B 2315/004.

Sorption machines, plant, or systems, operating intermittently, e.g. absorption or adsorption type
Definition statement
This subclass/group covers:

Sorption machines, plant, or systems with alternating periods of vaporization and condensation.

References relevant to classification in this group
This subclass/group does not cover:
Sorption machines, plant, or systems, operating continuously
Informative references
Attention is drawn to the following places, which may be of interest for search:
Boilers, analysers, rectifiers
Boiler-absorbers, i.e. usable for absorption or adsorption
Absorbers, Adsorbers
Special arrangements or features of sorption refrigeration cycles
Machines, plant, or systems, using evaporation of a refrigerant but without recovery of the vapour
Special rules of classification within this group

Devices using liquefied gases were historically classified in F25D 3/10.

Only to be classified in F25D 3/10 in case of a cold room.

Machines, plant, or systems, using electric or magnetic effects { (magnetic refrigerating material H01F 1/012 and H01F 1/017) }
Definition statement
This subclass/group covers:

Machines, plant, or systems, using electric or magnetic effects.

References relevant to classification in this group
This subclass/group does not cover:
Magnets, Selection of materials for their magnetic properties
Informative references
Attention is drawn to the following places, which may be of interest for search:
Details of machines, plants, or systems using electro-caloric effects
Details of machines, plants, or systems using magneto-caloric effects
Details of machines, plants, or systems using thermionic electron cooling effects
Special rules of classification within this group

Additional classification of details of machines, plants, or systems using

electro-caloric effects in F25B 2321/001;

magneto-caloric effects in F25B 2321/002;

thermionic electron cooling effects in F25B 2321/003

using Peltier effect; using Nernst-Ettinghausen effect (thermo-electric elements H01L 35/00, H01L 37/00)
References relevant to classification in this group
This subclass/group does not cover:
Peltier energy production
Thermo-electric elements
Informative references
Attention is drawn to the following places, which may be of interest for search:
Semiconductor devices
Details of machines, plants, or systems using Peltier effects
{using selective radiation effect}
Definition statement
This subclass/group covers:

Cooling by radiation to the night sky, e.g. by selective coating on a (night sky) radiator.

{boiling cooling systems}
Informative references
Attention is drawn to the following places, which may be of interest for search:
Heat-exchange apparatus in which the medium condenses and evaporates, e.g. heat pipes
Machines, plant, or systems, using a combination of modes of operation covered by two or more of the groups F25B 1/00 to F25B 23/00 (combinations of two or more modes of operation covered by a single main group, see the relevant group)
Definition statement
This subclass/group covers:

Machines, plant, or systems, using a combination of modes of operation covered by two or more of the groups F25B 1/00 to F25B 23/00.

Special rules of classification within this group

Combinations of two or more modes of operation covered by a single main group, see the relevant group.

{using primary and secondary systems}
Informative references
Attention is drawn to the following places, which may be of interest for search:
Arrangements for circulating liquids
Pump speed control
Special rules of classification within this group

Classification in F25B 25/005 when focus is on primary side of refrigeration cycle. However classification in F25D 17/02 when focus is on secondary side of the refrigeration cycle.

Machines, plant, or systems, using particular sources of energy (F25B 30/06 takes precedence)
Definition statement
This subclass/group covers:

Machines, plant, or systems, using particular sources of energy should be read as driven by particular sources of energy.

References relevant to classification in this group
This subclass/group does not cover:
Use of solar heat
Informative references
Attention is drawn to the following places, which may be of interest for search:
Refrigeration system using an engine for driving a compressor
Special rules of classification within this group

F25B 30/06 takes precedence.

Refrigeration system using an engine for driving a compressor are additionally classified in F25B 2327/00.

Combined heating and refrigeration systems, e.g. operating alternately or simultaneously
Definition statement
This subclass/group covers:

Combined heating and refrigeration systems, e.g. operating alternately or simultaneously should be read as operating simultaneously.

Special rules of classification within this group

Only classify in F25B 29/00 when cooling and heating is used simultaneously.

F25B 13/00 takes precedence.

Heat pumps
Definition statement
This subclass/group covers:

Refrigeration systems employed for heating, by using the heat given off by the condenser.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Central heating systems using heat pumps
Water-cooled condensers
Special rules of classification within this group

When classifying heat pump circuits or systems, groups F25B 1/00 to F25B 25/00 and F25B 29/00 take precedence over group F25B 30/00. Classification in F25B 30/00 when heat of condenser is used for a specific purpose, e.g. hot tap water.

Compressor arrangements (compressors per se F04)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Machines or engines in general
Compressors (lubrication of)
Cooling of compressors
Cooling of compressors by injecting a liquid in the gas to be compressed
Boilers; Analysers; Rectifiers (boiler-absorbers F25B 35/00)
Definition statement
This subclass/group covers:

Boilers/generators: that part of an absorption machine in which the refrigerant vapour is driven off by heat.

Analysers: a small fractionating column, in an absorption machine between generator and rectifier or condenser.

Rectifiers: that part of an absorption machine in which entrained absorbent is removed from the refrigerant vapour before condensation.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Boilers, Analysers, Rectifiers
Special arrangements of details of boilers; Analysers; Rectifiers
Boiler-absorbers, i.e. boilers usable for absorption or adsorption
Definition statement
This subclass/group covers:

Boiler-absorbers, i.e. boilers usable for absorption or adsorption

Informative references
Attention is drawn to the following places, which may be of interest for search:
Sorption machines, plant, or systems, operating continuously, e.g. absorption type
Sorption machines, plant, or systems, operating intermittently, e.g. absorption or adsorption type
Absorbers; Adsorbers (boiler-absorbers F25B 35/00; separating processes involving the treatment of liquids with adsorbents B01D 15/00; separation of gases or vapours by adsorption B01D 53/02; separation of gases or vapours by absorption B01D 53/14; investigating using adsorption or absorption G01N 30/00) ; { (absorption or adsorption in general B01J 20/00) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Separating processes involving the treatment of liquids with adsorbents
Separation of gases or vapours by adsorption
Separation of gases or vapours by absorption
Liquid distributor absorbing units
Absorption or adsorption in general
B01J1/22
Boiler-adsorbers
Investigating using adsorption or absorption
Evaporators; Condensers
Definition statement
This subclass/group covers:

Evaporators: heat exchangers in which liquid refrigerant is vaporized to produce refrigeration;

Condensers: heat exchangers in which refrigerant vapour is liquefied by removal of heat.

References relevant to classification in this group
This subclass/group does not cover:
CO2 radiators/gas coolers
Informative references
Attention is drawn to the following places, which may be of interest for search:
Heat-exchange apparatus not provided for in another subclass
Details of heat-exchange or heat-transfer apparatus of general application
Elements constructed in the shape of a hollow panel, e.g. with channels
Special arrangements or details of evaporators
Special arrangements or details of condensers
Special rules of classification within this group

Classification in F25B 39/00 when both evaporator and condenser are claimed.

When a heat exchanger, e.g. evaporator is claimed, classify in F25B 39/00 and F25B 39/02/CCA.

When a heat exchanger, e.g. condenser is claimed classify in F25B 39/00 and F25B 39/04/CCA.

Special arrangements or details of evaporators are additionally classified in F25B 2339/02.

Special arrangements or details of condensers are additionally classified in F25B 2339/04.

Subcoolers, desuperheaters or superheaters
Definition statement
This subclass/group covers:

Subcoolers: Heat exchangers, after the condenser, for subcooling the condensed refrigerant. Sometimes also called supercooler.

Desuperheaters: Heat exchangers, preceding the condenser for removing all or part of the superheat.

Superheaters: Heat exchanger in which wet vapour leaving an evaporator is dried and superheated.

Special rules of classification within this group

When heat-exchanger is a combination of heat-exchangers of sub-groups F25B 40/02, F25B 40/04 or F25B 40/06 classify in F25B 40/00 and two out of three of F25B 40/02/CCA, F25B 40/04/CCA or F25B 40/06/CCA.

Fluid-circulation arrangements, e.g. for transferring liquid from evaporator to boiler (pumps per se, sealings therefor F04)
Definition statement
This subclass/group covers:

Fluid-circulation arrangements, e.g. for transferring liquid from evaporator to boiler.

Ejector refrigeration cycle with the ejector used as expansion device.

Free or natural cooling.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Pumps, sealings therefor
Valves
Regulating valves
Special arrangements or details of ejectors not being used as compression device
Special rules of classification within this group

Ejectors used as expansion device are classified in F25B 41/00 and F25B 2341/001

Ejectors operating as compressor are classified in F25B 1/06 or F25B 1/08.

A compression cycle with natural or free cooling mode is classified in F25B 41/00 in combination with F25B 2400/0401 and F25B 2400/0411.

{fluid line arrangements}
Definition statement
This subclass/group covers:

Pipe structures: connections, fittings, joints.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Pipes; Joints or fittings for pipes; supports for pipes cables or protective tubing; Means for thermal insulation in general
Arrangements for charging or discharging refrigerant
[Expansion valves (regulating valves per se G05D) ]
Informative references
Attention is drawn to the following places, which may be of interest for search:
Special arrangements or details of flow restrictors or expansion valves
Control of expansion valves
Special rules of classification within this group

Additionally classify special arrangements or details of flow restrictors or expansion valves in F25B 2341/06.

Additional classification of control of expansion valves in F25B 2600/2513.

Regulating valves per se G05D.

{capillary tubes}
Definition statement
This subclass/group covers:

Flow restrictor with fixed opening.

Arrangements for separating or purifying gases or liquids (in analysers or rectifiers F25B 33/00) ; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat (F25B 40/00 takes precedence)
Definition statement
This subclass/group covers:

Arrangements for separating or purifying gases or liquids

Informative references
Attention is drawn to the following places, which may be of interest for search:
Arrangements for separating or purifying gases or liquids in analysers or rectifiers
Special rules of classification within this group

F25B 40/00 takes precedence.

{filters (in general B01D) }
Definition statement
This subclass/group covers:

Filters and/or driers.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Filters in general
{accumulators}
Informative references
Attention is drawn to the following places, which may be of interest for search:
Suction acumulators with deflectors
Receivers
Special rules of classification within this group

Additonal classification of high pressure receivers in F25B 2400/16.

Arrangements for charging or discharging refrigerant
Definition statement
This subclass/group covers:

Charging/discharging of refrigerant to/from a cycle from an external source.

Balancing of refrigerant within a cycle.

Informative references
Attention is drawn to the following places, which may be of interest for search:
Means for monitoring, testing or servicing the air-conditioning of vehicles
Details for charging or discharging refrigerants; Service stations therefor
Special rules of classification within this group

Details for charging or discharging refrigerants and details of service stations are additionally classified in F25B 2345/00 and lower.

{for preventing frost}
Definition statement
This subclass/group covers:

Preventing frost/condensation.

Defrosting cycles
Informative references
Attention is drawn to the following places, which may be of interest for search:
Alternate defrosting
Special rules of classification within this group

Classification in F25B 47/02 when heat for defrosting is extracted from refrigerating cycle itself, otherwise classify in F25D 21/00. Details of defrosting cycles are additionally classified in F25B 2347/02 and lower.

Arrangement or mounting of control or safety devices (testing refrigerators G01M; control in general G05)
Informative references
Attention is drawn to the following places, which may be of interest for search:
Compressor control in general
Testing refrigerators
Control in general
Motors
{of safety devices (F25B 49/02 and F25B 49/04 take precedence) }
Definition statement
This subclass/group covers:

Also classification of monitoring devices.

Special rules of classification within this group

F25B 49/02 and F25B 49/04 take precedence.

for compression type machines, plant or systems
References relevant to classification in this group
This subclass/group does not cover:
Control of air-conditioning reheater
Control of expansion valve only
Defrost control
Control of multiple evaporators
High pressure supercritical control the refrigerant being carbon dioxide
Informative references
Attention is drawn to the following places, which may be of interest for search:
Compressor control in general
Testing refrigerators
Control in general
Motors
Control of expansion valves
Sensing or detecting of parameters; Sensors therefor
{ Compressor control arrangements (in general F04B) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Compressor control
Sensing or detecting of parameters; Sensors therefor
Special rules of classification within this group

Details of compressor control are additionally classified in F25B 2600/02.

Details of sensing or detecting of parameters and sensors therefor are additionally classified in F25B 2700/00.

{Motor control arrangements (motors per se H02K) }
Informative references
Attention is drawn to the following places, which may be of interest for search:
Compressor control inverters therefor
Sensing or detecting of parameters; Sensors therefor
Special rules of classification within this group

Details of inverter compressor control are additionally classified in F25B 2600/02.

Details of sensing or detecting of parameters and sensors therefor are additionally classified in F25B 2700/00.

{Condenser control arrangements}
Informative references
Attention is drawn to the following places, which may be of interest for search:
Fan speed control of condenser fans
Sensing or detecting of parameters; Sensors therefor
Special rules of classification within this group

Details of fan speed control of condenser fans are additionally classified in F25B 2600/02.

Details of sensing or detecting of parameters and sensors therefor are additionally classified in F25B 2700/00.

This page is owned by Office of Patent Classification.
Last Modified: 10/11/2013