R32 Calculator

R32 Calculator

R32 calculator is a practical and user-friendly tool that determines within 4 steps the refrigerant charge limits of MHI air-conditioning systems using R32 in indoor spaces.

When mildly flammable refrigerants such as R32 are used within an air-conditioning system, safety checks and proper risk assessment should be performed to minimise any risk of toxicity and flammability. Depending on the total refrigerant charge of the system, indoor unit(s) must comply with minimum installation floor area requirements. To do so, MHIAE has decided to follow the standards below:

  • IEC 60335-2-40 Ed 6.0: Household and similar electrical appliances – Safety –

This international product-family standard covers the safety requirements of Air Conditioners and Heat Pumps (including hot water heat pumps). In January 2018, Edition 6.0 of the standard was published, adding the requirements for refrigerating systems charged with A2L mildly flammable refrigerants. Annex GG specifies the maximum charge, minimum installation floor area limits, and the relevant appropriate safety measures to comply with flammability requirements.

  • EN 378-1:2016 + A1:2020: Refrigerating systems and heat pumps — Safety and environmental requirements

This horizontal and generic standard covers a wide range of products including Air Conditioners and Heat Pumps. It consists of 4 parts and in its latest 2016 version, the requirements for refrigerating systems charged with A2L refrigerants were added. Part 1 – Annex C specifies the maximum charge and minimum installation floor area limits to comply with flammability and toxicity requirements.

Both standards state that when there is an available product-family standard, such as the IEC, it should take precedence over horizontal and generic standards covering the same topics, such as the EN.  To reduce confusion and clarify, MHIAE have decided to follow IEC 60335-2-40 Ed6.0 for the flammability risk assessment and EN 378:2016 + A1:2020 for the toxicity risk assessment.