The large number of refrigerated display cases used in modern supermarkets has a major impact on the total energy consumption. Even the slightest increase in efficiency can therefore make a significant contribution to reducing both the carbon footprint and the energy bill. Since the fan is the simplest energy consuming part of the display case, it is an ideal target for saving energy.
Traditionally, the standard motor used in these types of application would be the square, shaded pole Q-motor which, although robust, has a very low efficiency of around 25%. Not only is three quarters of the energy input wasted, but it’s lost as heat in a system which is designed to keep things cool, reducing overall efficiency even further.
New technology has now caught up with the Q-Motor and its demise will surely be welcomed by environmentalists and energy managers alike. Over the last few years a new fan, based on an Energy Saving Motor (ESM), has been steadily replacing it in both new build equipment and major retrofit programmes.
According to Tom Martin, Application Engineer at fan manufacturer ebm-papst, “ESM fans require up to 60% less power input to do the same amount of work and, having the same overall dimensions as the Q-Motor, they can be easily substituted without any redesign of the display case. They have two programmable speeds, allowing a low speed setting for night time operation when there is less refrigeration required. This in itself has the potential to reduce energy consumption by up to 35% in comparison to the motor running at full speed.”
Unlike the Q-motor’s mix-and-match motor/impeller combinations the ESM comes as a one piece, fully balanced motor and fan assembly which reduces the load on the bearings. Together with the lower motor running temperature this means that the life expectancy of an ESM can be up to three times that of the standard Q-motor resulting in reduced maintenance costs, fewer replacements and significantly lower cost of ownership for both the manufacturer and the end user.
With rising fuels bills, governments and supermarkets setting themselves challenging targets for carbon reduction and a consumer led demand for more environmentally friendly products, refrigerated display case manufacturers now have a great opportunity to meet this demand, benefitting both their business and the environment.
For further details on the new ESM and other energy saving EC fans contact ebm-papst UK on 01245 468555. www.ebmpapst.co.uk