AirCon Energy Savers Can Reduce Your Air Conditioning Energy Bill by 20-30%!

Air conditioning units are sized for peak load conditions, i.e. for the one or two hottest days of the year, plus a safety margin.  In most operational conditions, actual heat loads are a lot smaller, which means that most of the time, your air conditioner's capacity far exceeds the cooling requirements.

The majority of common window/wall and split systems are what’s known as “single speed” systems.  They have no mechanism to match the system’s cooling capacity to the instantaneous heat load.  They are like a car whose accelerator is stuck wide open - it can only drive flat-out or switch off. Clearly controlling the car precisely using this driving technique would be very difficult, especially when the engine is far more powerful than necessary - this analogy applies very well to a single speed air conditioner operating at less than maximum heat load conditions. 

In most air conditioners, the compressor is by far the largest consumer of electrical energy, typically accounting for at least 80% of energy consumption.

The compressor essentially provides the energy to cause cooling of the evaporator coils.  However when the heat load is less than the maximum capacity of the unit, a point of thermodynamic saturation is reached in the refrigerant where the coil temperature doesn’t drop any further regardless of any extra cooling energy provided by the compressor.  At this point, one can think of the evaporator coils as being fully “charged up”. Continued running of the compressor past this point is wasteful because little further thermodynamic effect is achieved.

Temporarily switching the compressor off at this point will eliminate wasted energy without having any appreciable effect on the cooling process.  The compressor can be restarted after a while when the refrigerant is no longer saturated.  Unfortunately most simple air conditioners have no way of detecting this saturation point, they simply keep running the compressor flat out until the room thermostat is satisfied.  A large amount of energy is thus wasted in that way.

The Aircon Energy Saver is designed to detect the thermodynamic saturation point and switch off the compressor accordingly, without affecting the unit's response to the thermostat setting or short cycling the compressor.

The Aircon Energy Saver thus enables far more precise control of the compressor at any given heat load in a cost effective manner for small and medium sized single speed air conditioners.  It was designed in the UK, where it won the 2006 National Energy Efficiency Award for Best Product.  It is easily installed as a cost effective retrofit to almost any common window/wall and single split system.

Larger centralised air conditioning systems often address this same problem by using a variable speed drive to control the compressor (also called an inverter controlled system) to improve efficiency by matching cooling capacity and heat load by continuously changing the compressor speed.  Unfortunately variable speed solutions are typically too expensive and complex to make economic sense for smaller stand-alone air conditioners.  The Aircon Energy Saver now achieves similar results at a fraction of the cost for smaller air conditioners!

Please contact us if you would like to test a unit!