A controller comprising processing circuitry, an interface, and a computer readable storage medium comprising instructions that, when executed by the processing circuitry, cause the controller to: receive data regarding the type and weight of refrigerant circulating in an HVAC system through the interface from a manufacturer and/or operator of the HVAC system ; receive data regarding a lower flammability limit of a refrigerant circulating in the HVAC system through the interface; determine an air flowrate of an air blower of the HVAC system based on data received through the interface from one or more components of the HVAC system; calculate a threshold value based on a minimum required air flowrate, wherein: the minimum air flowrate is calculated based on a mass of the refrigerant in the HVAC system and the lower flammability limit corresponding to the refrigerant, the mass of the refrigerant in the HVAC system and the lower flammability limit corresponding to the refrigerant received by the controller through the interface; and the threshold value is greater than the minimum air flowrate; in response to determining that the air flowrate of the air blower is less the threshold value, send a notification to an operator of the HVAC system indicating that the air flowrate of the air blower is less than the threshold value; and in response to determining that the air flowrate of the air blower is less than the minimum required air flowrate, shut down the HVAC system such that the refrigerant is no longer circulated by the componentry of the HVAC system . receive data regarding the type and weight of refrigerant circulating in an HVAC system through the interface from a manufacturer and/or operator of the HVAC system ; receive data regarding a lower flammability limit of a refrigerant circulating in the HVAC system through the interface; determine an air flowrate of an air blower of the HVAC system based on data received through the interface from one or more components of the HVAC system; calculate a threshold value based on a minimum required air flowrate, wherein: the minimum air flowrate is calculated based on a mass of the refrigerant in the HVAC system and the lower flammability limit corresponding to the refrigerant, the mass of the refrigerant in the HVAC system and the lower flammability limit corresponding to the refrigerant received by the controller through the interface; and the threshold value is greater than the minimum air flowrate; the minimum air flowrate is calculated based on a mass of the refrigerant in the HVAC system and the lower flammability limit corresponding to the refrigerant, the mass of the refrigerant in the HVAC system and the lower flammability limit corresponding to the refrigerant received by the controller through the interface; and the threshold value is greater than the minimum air flowrate; in response to determining that the air flowrate of the air blower is less the threshold value, send a notification to an operator of the HVAC system indicating that the air flowrate of the air blower is less than the threshold value; and in response to determining that the air flowrate of the air blower is less than the minimum required air flowrate, shut down the HVAC system such that the refrigerant is no longer circulated by the componentry of the HVAC system . <EOS>