Cooperative Patent Classification


CPC Definition - Subclass F24F

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Last Updated Version: 2018.08
AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING (removing dirt or fumes from areas where they are produced B08B 15/00; vertical ducts for carrying away waste gases from buildings E04F 17/02; tops for chimneys or ventilating shafts, terminals for flues F23L 17/02)
Definition statement

This place covers:

Methods and apparatus for air-conditioning, i.e. the supply of air to rooms or spaces by means which provide for the treatment of the air in at least two of the following ways:

  • Heating
  • Cooling
  • Any other kind of treatment, e.g. humidification

Methods and apparatus for humidification of air for rooms or spaces

Methods and apparatus for supplying air or extracting air from rooms or spaces, either by forced movement (for example by fans) or by natural effects (for example convection)

Methods and apparatus for circulating air within rooms or spaces, either by forced movement (for example by fans) or by natural effects (for example convection)

Methods and apparatus for use of air currents for screening, for example of entrances of buildings or of areas where particular operations are performed

Use of energy recovery systems in air conditioning, ventilation or screening

Details, for example control arrangements, safety arrangements, ducting arrangements or air flow control members, which are specially adapted for the methods or apparatus specified above

Devices, systems and methods for changing the air characteristics within a room, a building or spaces, comprising air treatment like air-conditioning, air-humidification, dehumidification of room air, cleaning e.g. filtering of room air, ventilation, use of air currents for screening.

Air treatment to improve the air properties of breathing air for human beings in the room or building.

Relationships with other classification places

As regards air-conditioning, air-humidification and ventilation, this subclass is an application-oriented place that covers methods or apparatus for these processes when specially adapted for rooms or spaces that are primarily intended as dwelling or working-spaces for human beings.

Air-treatment or ventilation that is specially adapted for particular processes or for other particular environments, for example for industrial processes or for housing of animals, is covered in the places for those processes or environments. For examples of such places see the section "Examples of places where the subject matter of this subclass is covered when specially adapted, used for a particular purpose, or incorporated in a larger system" below.

With the exception of humidification, this subclass does not cover the mere treatment of air being supplied to, extracted from, or circulated within, rooms or spaces. Such treatment of air in general, for example heating, cooling, heat-exchange or filtering, is covered in several different places of the CPC, see for example the entries under "Informative References" below.

This subclass does not cover elements or apparatus in general for transporting air or for regulating air flow, for example fans, ducts or valves. Such elements and apparatus are covered in several different places in the CPC, see for example the entries under "Informative References" below.

This subclass does not cover ventilation of garments or furniture or other devices, which is covered by the places for those devices, for example classes classes A41 - A47 for garments and furniture and class H01 for electrical devices.

Subclass F24F covers arrangement of cooling and heating. The relative arrangement of merely heating is covered by F24D and F24H.

Subclass F24F covers air-conditioning units characterised by the treatment of air. Air-conditioning units characterised by the refrigerant machines or systems per se are covered by F25B.

References
Limiting references

This place does not cover:

Removing dirt or fumes from areas where they are produces

Vertical ducts; Channels, e.g. for drainage for carrying away waste gases, e.g. flue gases

Chimney or flues

Application-oriented references

Examples of places where the subject matter of this place is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Ventilating arrangements for forage silos

Devices for ventilating greenhouses

Air-conditioning systems for greenhouses

Ventilation in animal husbandry

Controlling humidity in incubators for poultry

Treatment rooms with artificial climate for medical purposes

Devices for reconditioning breathing air in sealed rooms or for ventilating gas-proof shelters

Devices for ventilating gas-proof shelters

Containers or portable cabins for affording breathing protection with devices for reconditioning the breathing air or for ventilating

Dust-free rooms or enclosures for laboratories

Ventilation, air-conditioning, or cooling, specially adapted for passenger or goods spaces of vehicles

Air curtains at doors or windows of vehicles

Ventilation of driving cabins or engine rooms of locomotives or motor railcars

Heating, cooling, ventilating, or air-conditioning, specially adapted for rail vehicles

Adaptations of ventilation, cooling, heating, or air-conditioning for submarines or other underwater vessels

Arrangements of ventilation, heating, cooling, or air-conditioning specially adapted for ships or other waterborne vessels

Arrangements or adaptations of air-treatment apparatus for crew, passenger or freight spaces in aircraft

Arrangements or adaptations of devices for treatment of the atmosphere in cosmonautic vehicles

Drying cabinets or drying chambers having heating or ventilating means

Special arrangement or operation of ventilating devices in lavatories

Drying building constructions in general or keeping them dry, e.g. by air vents

Special adaptations of floors for incorporating ventilation ducts

Ceilings having means for ventilation

Ventilation of roof coverings

Ventilation of tents

Ventilation in doors or windows

Ventilation of mines or tunnels

Cooling or drying of air in mines or tunnels

Arrangements for supplying or controlling air or gases for drying solid materials or objects

Cooling, ventilating or heating of electric apparatus

Informative references

Attention is drawn to the following places, which may be of interest for search:

Disinfecting or sterilising of air

Filtering, washing or drying of gases

Mixing gases with vapours or liquids in general

Transportable units for separating dispersed particles from air by electrostatic effect

Spraying

Production of ozone

Heat, sound or noise insulation, absorption, or reflection

Air-ducts or air channels in buildings

Chimney stacks or similar ducts

Fans in general, details of fans

Pumping installations for air

Valves in general

Devices for venting or aerating enclosures in general

Pipes in general, joints, fittings or supports therefor

Noise absorbers for ducting

Thermal insulation for ducting

Devices for conducting smoke or fumes, e.g. flues

Air supply; draught-inducing; supplying non-combustible liquid or gas, tops for chimneys and ventilating shafts

Domestic stoves

Domestic or space-heating systems

Hot air central heating systems

Fluid heaters, water or air-heaters

Air heaters having heat generating means

Refrigeration in general, details of refrigeration systems

Combined heating and refrigeration systems

Production, working, storing or distribution of ice

Refrigerators, cold rooms, e.g. for food storage

Heat exchange apparatus in general, details of heat exchangers

Measuring temperature or quantity of heat in general

Testing apparatus not otherwise provided for

Control of flow in general

Control of humidity in general

Control of temperature in general

Ion sources

Arrangements for cooling, heating or ventilation of semiconductor or other solid state devices

Apparatus for generating ions to be introduced into non-enclosed gases

Arrangements in telecontrol or telemetry systems in general

Special rules of classification

Air-humidification as auxiliary treatment in air-conditioning, i.e. in units wherein the air is also either cooled or heated, is covered by groups F24F 1/00 or F24F 3/14, while air-humidification per se, e.g. "room humidifiers", is covered by group F24F 6/00.

Looping references between B08B 15/00 and F24F have been identified. Until this inconsistency is resolved, the current classification practice in CPC is as follows: B08B 15/00 is a limiting reference for subclass F24F. F24F is an informative reference for main group B08B 15/00.

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Air-conditioning

Supply of air to rooms or spaces by means which provide for the treatment of the air in at least two of the following ways: heating, cooling, any other kind of treatment, e.g. humidification.

Supplied air

Air entering the room

Exhaust air

Air withdrawn from the room

Ventilation

Supply of air to rooms or spaces, extraction of air from rooms or spaces, or circulation of air within rooms or spaces.

Room units, e.g. separate or self-contained units or units receiving primary air from a central station {or with supply of heating or cooling agents from a central station, such as those applied to air-treatment systems included in F24F 3/00 and F24F 5/00}
Definition statement

This place covers:

  • Air-conditioning units placed within a room for cooling the room, i.e. fan coil unit of a split unit. These indoor units can thereby recive primary air from a central station and/or recirculate the air within the room and/or supply outside air.
  • Split unit comprising an indoor unit and an outdoor unit.
  • Outdoor unit of split unit.
  • Self-contained units.

Usually, these room units comprise a refrigerant cycle.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Central station centrally producing cool air for distributing cool air in a plurality of rooms

Systems comprising multiple indoor units

Dehumidification

Filter units per se

Humidification

Control of room units

Vanes or dampers of room units

Casing of indoor units and self-contained units

Condensate evacuation

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Split unit

Air conditioning unit in split configuration, often with the compressor and condenser located in a separate external outdoor unit and the evaporator located in an indoor unit, the two units being connected via refrigerant pipes

Self-contained unit

Air conditioning unit with all apparatus for air treatment installed in a common casing, e.g. compressor, condenser and evaporator

Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems (room units F24F 1/00)
Definition statement

This place covers:

Air-conditioning systems in which conditioned primary air is supplied from one or more central stations to distributing units in the rooms or spaces where it may receive secondary treatment; Apparatus specially designed for such systems.

References
Limiting references

This place does not cover:

Room units

Informative references

Attention is drawn to the following places, which may be of interest for search:

Room humidifier

Mounting arrangement of air filters

Disinfection, sterilisation or deodorisation or air

Filter unit per se

Drying of gases

Electric filter

Cogeneration of electricity and heat or cold

Clean room for semiconductor production

Computer rooms

characterised by the arrangements for the supply of heat-exchange fluid for the subsequent treatment of primary air in the room units
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Arrangement or assembly of components for the regulation of the supply of heating or cooling media for the secondary treatment of air

Air-conditioning systems or apparatus not covered by F24F 1/00 or F24F 3/00 {, e.g. using solar heat or combined with household units such as an oven or water heater}
Definition statement

This place covers:

  • Exclusively-fluid system, e.g. using water as cooling fluid (F24F 5/0003),
  • Cooling apparatus specially adapted for use in air-conditioning, e.g. using absorption or desorption (F24F 5/0014), or using cold storage body (F24F 5/0017) (e.g. PCM material for storage), or using evaporation (F24F 5/0035).
  • Cooling apparatus using the Peltier effect (F24F 5/0042).
  • Cooling apparatus using natural energy (F24F 5/0046), e.g. solar energy or air from the ground.
  • Cooling apparatus using thermal walls (F24F 5/0075),
  • Cooling apparatus using radiation from walls or ceiling (F24F 5/0089).
  • Cooling apparatus combined with domestic apparatus, e.g. boiler, heating system (F24F 5/0096).
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Absorption or desorption for humidification or dehumidification purposes

Air conditioning in containers

Apparatus using radiation from walls or ceiling for heating purposes only

Hot-water central heating system

Solar heat collector

Production of heat using geothermal energy

Cooling towers

Phase Change Material (PCM) in general

Air-humidification {, e.g. cooling by humidification}
Definition statement

This place covers:

Local unit for room humidification by evaporation of water in the air, or by water dispersion or by injection of steam in the air.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Humidification systems

Cooling using evaporation

Device to humidify the respiration air of patients

Spraying apparatus with rotating elements discharging water by centrifugal forces

Ultrasonic oscillator

Steam generation in boilers

Humidifying within a fuel cell

using nozzles
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Nozzles per se, spraying in general

Ventilation {, e.g. by means of wall-ducts or systems using window or roof apertures}
Definition statement

This place covers:

Systems or apparatus for supplying air to rooms or exhausting air from rooms or circulating air within the rooms.

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Ventilation control

Ventilation of animal housings

Hoods preventing escape of fumes from the area where they are produced

Ventilation systems of lifts

Roof-covering elements

Ventilation of roof coverings

Ventilation through double windows

Ventilation of mines or tunnels

Ventilators or fans per se

Removing cooking fumes

Glossary of terms

In this place, the following terms or expressions are used with the meaning indicated:

Natural circulation

Air circulation without active fan, e.g. chimney effect, using solar energy or using wind energy

using wall or window fans, displacing air through the wall or window
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

With heating elements

Room ventilators, portable ventilators

with forced air circulation, e.g. by fan {positioning of a ventilator in or against a conduit}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Ventilators per se

{fan combined with single duct; mounting arrangements of a fan in a duct}
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Construction of fans

Use of air currents for screening, e.g. air curtains
Definition statement

This place covers:

  • Air curtain delimiting two different spaces.
  • Air curtain in a wall opening delimiting a room from the outside
  • The air curtain can be obtained by using more than one jet or band.
References
Application-oriented references

Examples of places where the subject matter of this place is covered when specially adapted, used for a particular purpose, or incorporated in a larger system:

Air curtain for vehicles

Informative references

Attention is drawn to the following places, which may be of interest for search:

Clean air workstation

Means providing sterile air to operating tables in surgery

Removing cooking fumes

Air curtain in cold rooms

Control or safety arrangements
Definition statement

This place covers:

Control of HVAC devices or systems (F24F 11/00).

Elements or components of control device, e.g. flap or damper control, (F24F 11/89).

References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Air flow control members

Tilting members, e.g. louvre

Fire prevention or containment

Extinguishing or preventing fire

Controlling the speed of ventilators by varying driving speed

Control valve per se

Compressor control

Refrigerant flow control

Humidity control

Humidity control using electrical means

Temperature control using electrical means (thermostat)

Special rules of classification

Damper control controlling the rate of air-flow:

  • If increasing air pressure opens the damper, then classify in F24F 11/745
  • If increasing air pressure closes the damper, then classify in F24F 11/75
Use of energy recovery systems in air conditioning, ventilation or screening (with both heat and humidity transfer between supplied and exhausted air F24F 3/147)
Definition statement

This place covers:

Apparatus and systems with heat-exchange between supplied and exhausted air, e.g. using an air-to-air heat exchanger or using an intermediate fluid, e.g. heat pump.

References
Limiting references

This place does not cover:

Both heat and humidity transfer between supplied and exhausted air

Informative references

Attention is drawn to the following places, which may be of interest for search:

Heat-exchange in general

Heat-exchange apparatus, not provided for in another subclass, in which the heat-exchange media do not come into direct contact

Heat-exchange apparatus having plate-like conduit

Heat pipes

Details common to, or for air-conditioning, air-humidification, ventilation or use of air currents for screening
Definition statement

This place covers:

Details concerning ducting arrangements (F24F 13/02); Air outlets (F24F 13/06); Air-flow control members (F24F 13/08); Casing or covers (F24F 13/20).

Means for preventing or evacuating condensate (F24F 13/22).

Means for preventing or suppressing noise (F24F 13/24).

angement for air-circulation by means of air-induction (F24F 13/26).

Arrangement for mounting of filter (F24F 13/28), of heat exchanger(F24F 13/30).

Mounting means for HVAC devices (F24F 13/32).

References
Limiting references

This place does not cover:

Ventilating nozzles for vehicles

Informative references

Attention is drawn to the following places, which may be of interest for search:

Room units in which secondary air is induced by injection action of the primary air

Mounting of filtering elements within a casing

Ventilation combined with door or window frames

Butterfly valves

Support for pipes

Flange joints of pipes

Noise absorbers in pipes

Lighting devices combined with ventilating systems

Method or devices for protecting against noise

Air-mixing units (F24F 13/06 takes precedence {; room units for the mixing of pre-treated primary air with recirculated or room air F24F 1/00})
References
Limiting references

This place does not cover:

Room units for the mixing of pre-treated primary air with recirculated or room air

Outlets for directing or distributing air into rooms or spaces, e.g. ceiling air diffuser

Informative references

Attention is drawn to the following places, which may be of interest for search:

Mixing gases in general

combined with lighting fixtures
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Air-treatment systems with air-flow over lighting fixtures

Air-flow control members, e.g. louvres, grilles, flaps or guide plates (F24F 7/013F24F 13/06 take precedence)
References
Limiting references

This place does not cover:

Ventilation with forced flowusing wall or window fans, displacing air through the wall or window

Outlets for directing or distributing air into rooms or spaces, e.g. ceiling air diffuser

Informative references

Attention is drawn to the following places, which may be of interest for search:

Roof ventilation

movable, e.g. dampers
References
Informative references

Attention is drawn to the following places, which may be of interest for search:

Valves in general