Method and apparatus for refrigerant detector calibration confirmation

An HVAC system, comprising:

• an evaporator coil;
• a circulation fan disposed to direct air through the evaporator coil;
• a compressor fluidly coupled to the evaporator coil via a suction line;
• an HVAC controller;
• a metering orifice formed in the suction line;
• a valve fluidly coupled to the metering orifice and electrically connected to the HVAC controller;
• a mixing device fluidly coupled to the valve, the mixing device having an input orifice, an air intake and an output orifice, wherein the mixing device comprises a flow restriction positioned about an interior of the input orifice, wherein the flow restriction terminates at an end in the air intake and decreases in diameter relative to the input orifice at the end;
• and
• a refrigerant detector fluidly exposed to the output orifice.

An HVAC system, comprising:

• an evaporator coil;
• a circulation fan disposed to direct air through the evaporator coil;
• a compressor fluidly coupled to the evaporator coil via a suction line;
• an HVAC controller;
• a metering orifice formed in the suction line;
• a valve fluidly coupled to the metering orifice and electrically connected to the HVAC controller;
• a mixing device having an input orifice fluidly coupled to the connecting tube, the mixing device comprising:
• an air intake disposed proximate the input orifice;
• a flow restriction positioned about an interior of the input orifice, wherein the flow restriction terminates at an end in the air intake and decreases in diameter relative to the input orifice at the end;
• a throttling portion downstream of the input orifice and the air intake, the throttling portion having a reduced cross-sectional area;
• a diffuser section positioned downstream of the throttling portion, the diffuser section having an output orifice;
• and
• a refrigerant detector fluidly exposed to the output orifice.