Thermodynamics > Air conditioning & Refrigeration




This is a recirculating air conditioning unit with transparent windows and a climatic chamber.

Inlet air is cooled by a refrigeration system, heated by a preheater, and added moisture or latent heat by a humidifier before entering the climatic chamber for demonstration of climate control. The air in the climatic chamber is further heated by a reheater and a humidifier before leaving. A fan installed after the preheater is used to circulate the air in the duct. Part of the air leaving the climatic chamber is vented and the remaining is recirculated and mixed with fresh air entering the inlet duct. The amount of air recirculation is controlled by ventilation dampers. Steam generator, compressor and condenser are installed underneath the duct.

Measuring instruments are provided for air flow rate, and temperature and humidity at various stages. Additional instruments are provided for measurement of refrigerant flow rate, temperature and pressure as well as power for the compressor and heat sources.

The unit is on steel frame on wheels.   

Instruction manual is also included.

  • Familiarization with recirculating air conditioning system and components.


  • Determination of preheating, cooling and dehumidification, humidification, and reheating processes.


  • Energy balance in the preheater, evaporator, and reheater.


  • Demonstration of preheating, cooling and dehumidification, humidification, reheating, and mixing processes on psychrometric chart.


  • Demonstration of refrigeration cycle on Pressure-Enthalpy diagram of the refrigerant R134a.


  • Determination of recirculating and mixing process of moist air.


  • Effects of climatic chamber heat loads.

  • Air duct
: 250 x 250 mm, stainless steel sheet 
  • Climatic chamber
: Approx. 180 L 
  • Fan
: Adjustable speed 
- Maximum airflow rate: Approx. 750 m3/h 
  • Humidifier
: 3000 W, adjustable. 
  • Preheater
: 1200W, adjustable 
  • Reheater
: 600W, adjustable 
  • Heater controller
: 1 
  • Evaporator
: 250 x 250 mm 
  • Compressor
: Approx. 0.55 kW. 
  • Condenser
: with fan 
  • Refrigerant
: R134a 
  • Temperature controller
: 1 
  • Measuring instruments
- Sensors with digital display: Air flow rate, velocity sensor 
 : Temperatures at duct inlet, evaporator inlet, humidifier inlet, humidifier outlet , 
 reheater inlet and outlet, compressor inlet and outlet and condenser outlet. 
 : Power measurement for compressor, humiditier, preheater and reheater 
- Portable temperature/humidity meter: 0-50°C, 10-90% RH, at duct inlet, preheater inlet and climatic chamber outlet 
- Refrigerant rotameter  
- Pressure gauges : Compressor inlet and outlet 
  • Power supply
: 380 V 3 Ph 50 Hz. Other power supply is available on request. 

Net (unpacked) shipping dimensions WxLxH  : 70 x 270 x 185 cm

Net weight  : 320 kg

  • TH518S
Learning Software
 to support both online/offline training with data calculation and analysis by manual data entry from analog measuring instruments.
  • TH516-001

Humidity digital display instead of portable temperature/humidity meter

  • TH518-050

Computer Interface (computer not included)

                     This includes TH518S and significant sensor(s) instead of analog measuring instrument(s), data acquisition (capture, display, graph and/or data export), additional software function for real-time data logging with computer interface unit and WiFi feature for data logging and real-time display remotely on smartphone (iOS and Android)

  • TH516S
Learning Software
 to support both online/offline training with data calculation and analysis by manual data entry from analog measuring instruments.