The EM-2000-HB-RR1234yf air conditioning training equipment features the H-block integrated with thermal expansion valve (TXV) with R1234yf flow control. It can be connected to any air conditioning recycling or recovery equipment using the R1234yf ports. This fully operational equipment is used for demonstration of physics in air conditioning system. Students will be able to visually observe the operation and role of H-block air conditioning refrigeration cycle and understand the principle of refrigerant change of state at the receiver, evaporator and condenser. Instructors can introduce system faults or blockages for diagnostics learning.