Optimisation

Within the resource data management control and monitoring system there is the means to automatically adjust the central plant suction control set point. As the case cooling demand is reduced over time then the suction set point is raised incrementally, if the cooling demand shows a trend of increasing then the set point is returned gradually to its normal setting.

This case driven process ensures that food quality is not compromised by any power reduction activities.

On a site trial it was possible to optimise the operating set point from -12C to -8C equating to a compressor power input reduction of 14.5%

Trim heaters

Display cases fitted with Mercury refrigeration controllers have a built in feature which allows for the local or remote control of the trim heater electrical load. the load is varied by adjusting the on to off time ratio via a parameter setting.

From trial site data it has been possible to reduce the standing trim heater load by 25% with no visible detriment to the display case. The actual reduction value will vary depending on site humidity conditions but it is certain that a 10% initial reduction would present a no risk starting point from which greater power savings could be made.

A typical trim heater load of 1Kw reduced by 25% would save 2190 Kilo watt hours per annum. You can feed into the system a variable reading off the sales floor humidity and use that to constantly change the trim heater set point. This maximises the saving and minimises the risk.

Night blinds

Night blinds fitted to a display case reduce the power requirement of the case by 40% when the store is not trading.The most important element of this massive saving is to make sure the blinds have been used.

The Data Manager can profile the temperatures in a display case and can be programmed with the store opening hours - it will emit an audible or remote alarm to signify the blinds have not been used.

Product probe control

Conventional temperature control of display cases is via a combination of air on and off sensors. By installing a simulated product sensor on to the shelf of a display case the temperature of the case can be controlled to meet the cooling requirements of the actual product on the shelf.

The main benefit is to reduce unnecessary cooling of the product and therefore unnecessary power consumption.

As well as saving energy, the simulated product sensor also enables continuous product temperature monitoring in addition to the existing case air temperature monitoring. This gives increased safeguards against loss of stock and trading.