How It Works

INDOOR UNIT TYPE: there are four types of refrigerant containing indoor appliances for flammability
Height factor for
indoor unit
Floor Mounted 0.6
Window 1.0
Wall Mounted 1.8
Ceiling Mounted 2.2

LOCATION CLASSIFICATION: there are four equipment location classifications
  Location Examples
Class I all refrigerant equipment is located within the occupied space Fridge, freezer, window unit, portable unit
Class II Indoor unit(s) and pipework is in conditioned space and all compressors
and pressure vessels are in a machinery room or in open air
Split system, evaporator with remote condenser
Class III all refrigerating equipment is located in a machinery room or in open air Chiller, rooftop unit
Class IV all refrigeration equipment is in a ventilated enclosure Unitary package appliance

ACCESS CLASSIFICATION: there are three access types
  Definition Examples
A People may sleep;
The number of people present is not controlled;
Any person has access without being personally acquainted with the personal safety precautions
Hospitals and nursing homes
prisons, theatres, lecture halls, supermarkets, restaurants, hotels, transport terminals
ice rinks
B Only a limited number of people may be assembled, some of them being necessarily acquainted with the general safety precautions;
May be a room or part of a building
Places for general manufacturing
Office buildings
C Not open to the general public where only authorised persons are granted access;
Authorised persons are acquainted with general safety precautions
Non-public areas in supermarkets
Manufacturing facilities (e.g. chemicals, food)
Cold stores and abattoirs

CATEGORY CLASSIFICATION: there are three category types
Human comfort Air treatment for occupants
Other application Data rooms, archives, storage, cold room
<1 Person per 10 m² Authorised access risk aware

OTHER CRITERIA: additional design considerations
Selection Choice Effect
Compressor Open air or machinery room Requirement for emergency ventilation
Underground Yes Reduced charge limit restriction
Calculation method C.2 or C.3 C.2 flammability; C.3 refrigerant concentration
Emergency ventilation Yes Emergency ventilation rate m3/h
Multiple indoor unit check Indoor versus outdoor capacity 25% capacity restriction
Effect on flow down Refrigerant charge versus floor volume Concentration limit restriction
Air change rate Air change rate versus room volume Ventilation rate m3/h

Warnings on Refrigerant Leakage

R32 refrigerant is used in the air conditioner has a classification A2L lower toxicity lower flammability rating. If R32 refrigerant leaks and comes into contact with fire or heating part, it will create harmful gas and there is risk of fire. R32 refrigerant poses a potential risk of suffocation if its concentration should rise excessively. If an air conditioner system is installed in a small room, select a suitable model and installation procedure so that if the refrigerant accidentally leaks out, its concentration does not reach or exceed the limit. In a room where the concentration may exceed the limit, create an opening(s) with adjacent room(s) (that cannot be closed), or install mechanical ventilation combined with a gas leak detection device.

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R32 RCL: Refrigerant Concentration Limit in kg/m3

Not more
than (kg)
Factor Max. Limit
up to (kg)
m1 4 0.307  1.23 1.5 1.84 No restriction
m2 26 0.307  7.98 1.5 11.97* 1 Measure required + leak detection
m3 130 0.307 39.91 1.5 59.87** 2 Measures required + leak detection
* Max. charge occupied space ** Max. charge unoccupied space

Information referenced from EN378:2016 and issued for guidance only

Location classification of refrigerant system



General; Supervised; Authorised


Human comfort; Other application; Person density

R32 QLMV: Quantity Limit with Minimum Ventilation in kg/m3

Lower Flammability
Limit (LFL)

Indoor Unit




Volume by
Maximum Charge Limit
Calculation Method
Use Limits
Emergency Ventilation
Installed Charge (kg):
Carbon emissions CO2 Tonnes equivalent:
Minimum floor area (m2):
Installed Refrigerant Concentration (kg/m3):
RCL Limit (kg/m3): 0.061
QLMV Limit (kg/m3): 0.063
QLAV Limit (kg/m3): 0.15

R32 QLMV Check: effect of flow down

Building Lowest Floor Dimensions

R32 Largest system charge
Installed Refrigerant Concentration

Air change rate: effect of room size

Air change rate required Length
Air volume required m3/h

Please note
Information extracted from EN378:2016 and issued for guidance only.
Toshiba does not accept any responsibility for information displayed in this calculation tool.