Poor design can reduce refrigeration efficiency by 50%
“The energy efficiency of refrigeration systems is governed by the laws of physics and practicality. Efficiency is not only dependent on choice of refrigerant but also on good design, selection of an appropriate system and good maintenance.” - Institute of Refrigeration, Guidance note 18.
To optimise efficiency, attention needs to be given to the following:
Avoid refrigeration / reduce the cooling load
This is the most important first step - there is no point designing an efficient system is the load was unnecessary!
Get the overall system design right
For example; splitting loads at different temperatures onto different suction levels...
Get the control philosophy right
Don’t forget the “part load” operating conditions which are much more common than the peak “design point”.
- Head pressure control
- Partly loaded compressors
- Fixed speed auxiliaries like pumps and fans
Optimise individual components for efficiency
For example; can EC fans be utilised to increase condenser heat rejection? Can compressors be inverter controlled?
Operate and maintain the plant for best efficiency
- Clean condensers
- Maintain refrigerant levels
- Optimise discharge / suction pressures