AES Aircon Energy Saver® Frequently Asked Questions

In laymen’s terms how does the system work?

Typical air conditioning systems operate continually until the room thermostat is satisfied. During this time it will run the compressor and produce greater cooling capacity than the air can absorb.

1. The AES probe measures the temperature of the supply air to the space to be cooled, the ‘off coil temperature’ and constantly measures the rate of change.

2. At first the system will run and a minimum ‘off coil temperature’ will be established.

3. When the discharge temperature has been constant at or below the previous minimum for 3 minutes the compressor is switched off.

4. The compressor is held off for at least 3 minutes to allow any start-up heat generated in the electrical windings to dissipate (usually about 1.5 minutes).

5. At the end of the compressor off period the unit will only re-start when the off coil temperature has risen to 20°C (a figure chosen to maintain comfort levels in the room).

6. Depending on the system load the compressor run hours may be reduced by between 20% and 50% delivering significant energy savings.

Doesn’t the thermostat do the same job?

The thermostat is designed to maintain the room temperature set point. The thermostat does not analyse the performance of the hardware and will run the compressor until sufficient cooling has been produced to satisfy the required room temperature however, this normally results in overshoot of the set-point. The Aircon Energy Saver does not override the thermostat. It modulates the output of the Air-Conditioning unit preventing overshoot of the thermostat set-point whilst achieving an efficient cooling cycle by utilising the latent cooling characteristics of the air conditioning unit.

What effect does the AES have on room temperature?

No effect at all. The thermostat dictates the required room temperature; the AES removes the inefficient wasteful element of the operation.

Note: Not only does the room temperature remain unchanged but the AES will lessen the dryness of the air due to moisture being removed during the cooling process. This results in a healthier more comfortable working environment.
 
Surely, the interruption of the run times has a detrimental effect on the compressor?

The AES does not compromise the manufacturer’s minimum run time requirements which are an in-built safety feature. The AES is programmed to prevent short-cycling within the software, the result is a compressor that will actually run less and reduce wear and tear.

If air conditioning is used on cooler days when the thermal load is low the compressor will turn on and off more frequently anyway as the room thermostat switches around its set point. The most important objective is to ensure that the compressor remains running for at least 1.5 minutes (to dissipate excess startup heat generated in the motor windings). The AES ensures that the minimum running time following a start is 3 minutes.

Mean Time Between Failure calculations (MTBF) take into account hours of operation rather than number of start/stops. On balance the AES is probably neutral on compressor life but very much positive in terms of energy/fuel reduction.

What is the difference between the residential and commercial models?

The residential AES is designed for use with small aircon units (up to 3.5 kilowatt). The commercial AES is for high power aircon units, including those with a three phase power driven compressor. The largest unit we have dealt with to date is a 20 metric ton unit.

What would be the shipping weight of each unit if shipped direct to the customer?

The shipping weight of each unit is 600g.

What sizes of units will you provide? AC Volts

The AES is internal switchable between 110 Volts a.c. and 250 Volts a.c.

What is the maximum wattage/voltage that a single unit can maintain?

The internal relay can handle 10 amps. Should higher control currents be required then the AES can be used to control a separate high power control relay.

Will this unit work on a "Heat Pump" as well as an Air-conditioner?

The existing AES unit does not work on Heat Pumps however; the AES unit does work with reverse cycle air conditioners but only on the cooling cycle.

What does the sensor measure?

The sensor measures the temperature of the supply air to the space to be cooled at discharge from the evaporator, the ‘off coil temperature’ and monitors the rate of change.

What is the AES learning when it is powered on?

The AES is a self learning memory based unit that controls the compressor to achieve a balance between maximum cooling efficiency and minimal energy consumption. The unit is learning to regulate the compressor run times in order to satisfy the room thermostat without compromising the temperature of the room.

What is the experienced power reduction on an air-conditioning unit as a average?

The average energy reduction is 30% (measured as a reduced compressor energy demand). The saving range is between 15% and 60% depending on the actual climate conditions.