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Test chamber for buses and roof-mounted air conditioning systems

At our research & development site in Renningen, Eberspächer Sütrak operates a test chamber for buses as well as two measuring chambers for bus AC systems.

The 23-meter test chamber for buses is designed for all kinds of buses, whether they be a city bus, a coach, an articulated, double-decker, school or airport bus. At a simulated ambient temperature of 15 to 55 °C we carry out cooling tests with and without passenger simulation. To determine the heating performance, we conduct a test drive with your vehicle.

Test chamber for buses - services and possbile bus tests:

  • Cool down test at various ambient temperatures with/without
  • passenger simulation
  • Heating test on test drives
  • Measurement of the air speed distribution in the passenger cabin
  • Noise measurement
  • Rainwater test
  • Air flow rate measurement
  • Temperature distribution at outlet nozzles and in the passenger cabin
  • Component test on request

 Other services that we carry out to qualify our systems include:

  • AC system vibration test
  • Corrosion tests of heat exchangers and tubes
  • Noise-Vibration-Harshness tests (NVH) of fans, blowers and compressors
  • Pressure cycle test of the refrigerant and water circuit
  • Temperature cycle test of housing and plastic components
  • Function tests of bus heating Systems

 Control center:

We analyze and evaluate the tests in our control center. We use the results of all tests carried out internally and externally in our development work and make them available to our customers.

The two test chambers allow investigations to be carried out on conventional roof-mounted air conditioning systems and heat pump systems at an ambient temperature of –15 to 60 °C. We can conduct system tests with electrically and mechanically operated compressors in both chambers.



Measuring Chambers - scope and possible system tests:

  • Determination of the cooling/heating capacity of the system
  • Determination of the efficiency of the system
  • Determination of the system cut-off temperature
  • Condensation test in a humid environment
  • Determination of the electrical power consumption of fans and blowers at different operating conditions
  • Examination of expansion valve operation under worst-case conditions
  • Characteristic diagram measurement with variation of fan, blower and compressor speed
  • Fill quantity optimization at maximum load

General conditions:

  • Measurable cooling/heating capacity 1 – 50 kW
  • Refrigerant mass flow rate up to 30 kg/min
  • Simulatable ambient temperature –15 – 60 °C
  • Simulatable saloon temperature 15 – 50 °C
  • Simulatable saloon humidity 10 – 90% relative humidity
  • Saloon air flow rate 1,000 – 12,000 m³/h
  • Saloon back-pressure 0 – 300 Pa
  • Mechanical compressors Up to 30 kW
  • Electrical compressors 12/24 V or high-voltage compressors