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AIR-CONDITIONING, AIR-HUMIDIFICATION, VENTILATION, USE OF AIR CURRENTS FOR SCREENING (devices for ventilating greenhouses A01G { F24F9/24; air-conditioning systems for greenhouses A01G 9/246}; animal husbandry A01K, e.g. controlling humidity in incubators A01K 41/04; disinfecting or sterilising of air A61L; devices for reconditioning breathing air in sealed rooms or for ventilating gas-proof shelters A62B; filtering, washing or drying of gases B01D; mixing gases with vapours or liquids in general B01F 3/00; spraying B05B, B05D; removing dirt or fumes from areas where they are produced B08B 15/00; ventilation, air-conditioning or cooling, specially adapted for vehicles, see the relevant vehicle places, e.g. B60H, B61D 27/00, { B64D 13/00}; production of ozone C01B 13/10; chimneys or flues E04F 17/02, E04H 12/28, F23J 11/00, F23L 17/02; air ducts or conduits E0417/04, F16L; ventilation in doors or windows E06B 7/02; fans, blowers F04; noise-absorbing in pipes or pipe systems F16L; tops for chimneys and ventilating shafts F23L; cooling F25; details of heat-exchange or heat-transfer apparatus, of general application F28F; apparatus for generating ions to be introduced into non-enclosed gases, e.g. the atmosphere H01T 23/00)
Definition statement
This subclass/group covers:

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.

Relationship between large subject matter areas

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 relevant to classification in this subclass
This subclass/group does not cover:

Devices for ventilating greenhouses

Animal husbandry

Disinfecting or sterilising or air

Filtering, washing or drying of gases

Removing dirt or fumes from areas where they are produces

Ventilation, air-conditioning or cooling specially adapted for vehicles or aircrafts

Chimney or flues

Ducts in general

Fans or blowers per se

Refrigeration machines, systems of plants; heat pumps

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

Heat-exchanger and details of heat-exchanger

Domestic or space-heating systems

Fluid heaters, water or air-heaters

Cooling or ventilation of data center

Special rules of classification within this subclass

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

Glossary of terms
In this subclass/group, the following terms (or expressions) are used with the meaning indicated:

Air-conditioning

Air treatment of room air or spaces comprising at least cooling

Supplied air

Air entering the room

Exhaust air

Air withdrawn from the room

Ventilation

Supplying air to the room, exhausting air from the room and circulating air within the room

Synonyms and Keywords

In patent documents the following abbrevations are often used:

HVAC

Heating, ventilating and air conditioning

Rooms units, e.g. 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 (arrangement or assembly of components for the primary treatment of air F24F 11/08; mixing chambers for air F24F 13/04)}
Definition statement
This subclass/group 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 receive 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 relevant to classification in this group
This subclass/group does not cover:

Filter units per se

Humidification

Dehumidification

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

Systems comprising multiple indoor units

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

Casing of indoor units and self-contained units

Control of room units

Vanes or dampers of room units

Condensate evacuation

Glossary of terms
In this subclass/group, 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; construction of heat-exchangers F28){F24F 3/044 takes precedence; arrangement or assembly of components for the primary treatment of air F24F 11/08}
Definition statement
This subclass/group 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 relevant to classification in this group
This subclass/group does not cover:

Room humidifier

Mounting arrangement of air filters

Cogeneration of electricity and heat or cold

Room units

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

Disinfection, sterilisation or deodorisation or air

Filter unit per se

Electric filter

Drying of gases

Computer rooms

Clean room for semiconductor production

Air-conditioning systems or apparatus not covered by F24F 1/00 or F24F 3/00 { e.g. using solar heat; combined with household units such as an oven or water heater}
Definition statement
This subclass/group 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 relevant to classification in this group
This subclass/group does not cover:

Air conditioning in containers

Absorption or desorption for humidification or dehumidification purposes

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

Apparatus using radiation from walls or ceiling for heating purposes only

Production of heat using geothermal energy

Solar heat collector

Hot-water central heating system

Phase Change Material (PCM) in general

Cooling towers

Air-humidification, e.g. for increasing comfort in living spaces by "room humidifiers" { cooling by humidification}
Definition statement
This subclass/group 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 relevant to classification in this group
This subclass/group does not cover:

Device to humidify the respiration air of patients

Humidification systems

Cooling using evaporation

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

Spraying apparatus with rotating elements discharging water by centrifugal forces

Ultrasonic oscillator

Steam generation in boilers

Humidifying within a fuel cell

Ventilation, { e.g. by means of wall-ducts; systems using window or roof apertures}
Definition statement
This subclass/group covers:

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

References relevant to classification in this group
This subclass/group does not cover:

Ventilation of animal housings

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

Ventilation systems of lifts

Ventilation of mines or tunnels

Ventilators or fans per se

Removing cooking fumes

Ventilation control

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

Roof-covering elements

Ventilation of roof coverings

Ventilation through double windows

Glossary of terms
In this subclass/group, 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

Use of air currents for screening, e.g. air curtain (air curtains for vehicles B60J 9/04)
Definition statement
This subclass/group 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.
Informative references
Attention is drawn to the following places, which may be of interest for search:

Means providing sterile air to operating tables in surgery

Air curtain for vehicles

Removing cooking fumes

Clean air workstation

Air curtain in cold rooms

Control or safety systems or apparatus ({extinguishing or preventing fire A62C 3/14}; control valves per se F16K; humidity control G05D 22/00)
Definition statement
This subclass/group covers:

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

Elements or components of control device, e.g. flap or damper control, (F24F 11/02).

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

Fire prevention or containment

Extinguishing or preventing fire

Controlling the speed of ventilators by varying driving speed

Control valve per se

Air flow control members

Tilting members, e.g. louvre

Compressor control

Refrigerant flow control

Humidity control using electrical means

Temperature control using electrical means (thermostat)

Special rules of classification within this group

Damper control controlling the rate of air-flow:

  • If increasing air pressure opens the damper, then classify in F24F 11/043
  • If increasing air pressure closes the damper, then classify in F24F 11/047
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; heat-exchange in general F28)
Definition statement
This subclass/group 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 relevant to classification in this group
This subclass/group 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 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 subclass/group 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 relevant to classification in this group
This subclass/group does not cover:

Ventilating nozzles for vehicles

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

Mounting of filtering elements within a casing

Ventilation combined with door or window frames

Butterfly valves

Flange joints of pipes

Support for pipes

Noise absorbers in pipes

Lighting devices combined with ventilating systems

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

Method or devices for protecting against noise

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Last Modified: 10/11/2013