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AIR-CONDITIONING, AIR-HUMIDIFICATION, VENTILATION, USE OF AIR CURRENTS FOR SCREENING (devices for ventilating greenhouses A01G [N: 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, [N: 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 E04F 17/04, 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 [N: 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) [N: 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, [N: 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" [N: 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, [N: 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 ([N: 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