Callidus Design Consulting Engineers

Designers, engineers, consultants and technical specialists covering a wide range of building and process services.

Air Conditioning

 Refrigeration DX Cooling and Heat Pump Diagnosis and Rectification

There are several different types of refrigerant-based Air Conditioning (sometimes called air-con) systems installed in today's builings. From discrete systems with a sinlge indoor unit (evaporator or cassette) and a single outdoor unit (condenser). Next there are multiple indoor unit and single outdoor unit systems and lastly, multiple indoor and outdoor unit systems. Knowing which system to choose for which application can be a minefield. If the choice of the system is wrong or the selections of the components are mismatched the results can be disastrous resulting in high fuel bills and disgruntled building occupants.

Common complaints regarding air-conditioning are as follows:

  • Internal ceiling or floor mounted units are noisy in operation
  • Internal units do not provide sufficient cooling
  • Internal units cause cold draughts
  • External units are noisy in operation
  • External units do not provide sufficient cooling


There are a wide range of faults which can lead to any of the above symptoms including:

  • Wrong selection of internal or external unit for load or size of room
  • Incorrect location of internal unit relative to walls and doors
  • Insufficient refrigeration gas charge
  • External unit location relative to openable windows

 If you suffer any issues with your air conditioning systems please contact us to find out if our troubleshooting service can help.