Daikin’s approach for convenience stores shows its potential
As well as considerably reducing the amount of outdoor equipment, a Daikin Conveni-pack installation at a Co-op convenience store has reduced electricity bills by £400 a month.
Significant reductions in electricity costs have been achieved in just seven weeks since the installation of a Daikin Conveni-pack system for delivering refrigeration, air conditioning and heating at the Co-op Welcome convenience store at Sneiton Dale in Nottinghamshire. Weekly electricity consumption has been reduced by 17% to 5000 kWh a week compared with the same period the previous year. The monitored period included three weeks of higher-than-average temperatures during the summer. The sales floor of this store is about 23 x 12 m. The warehouse, office, kitchen and cooking area form an L shape at the rear and lead into the delivery yard. Chilled displays for sandwiches, fruit, vegetables and dairy produce are on one side of the store. There are chilled wines and beers along the other side, freezer cabinets at the rear and central island displays for other products. As well as reducing electricity costs, the Conveni-pack installation has solved a series of comfort issues. The main one was the common problem of cold aisles, with a temperature gradient of 4°C at knee level and 12°C at head level, against an ambient temperature of 27°C. Efforts to alleviate this problem with infra-red heaters above the aisles next to the chilled displays were generally unsatisfactory and also increased electrical consumption. Daikin’s solution is based around three Conveni-pack systems to deliver 40 kW of refrigeration at –10°C. Two ceiling-recessed fan-coil units blow heat-recovered air into canvas ducting installed at a height of about 2.25 m above floor level in areas next to the freezer cabinets, chilled aisles and central aisles. Air is delivered gently and evenly at an angle of 60° through jet nozzles in the ducting. A 4-way-blow ceiling cassette fan-coil unit supplies conditioned air to the till and chilled wine and beer areas. The system maintains a temperature of 20°C ±1 K throughout the store. Two 3-pipe outdoor condensers meet the requirements for refrigeration, air conditioning and heating. A 2-pipe system serves the chilled display cabinets. There is now also less plant outside. Bill Watson, technical consultant for refrigeration for the Co-operative Group, says, ‘The system was chosen due to several constraints, both within and outside the store. These include the cold store effect, which certainly seems to have been solved, and energy consumption — which is down, and all additional heating has now been removed. ‘Also, the new equipment has created more space in the delivery areas and, due to its small footprint, has enabled us to overcome all planning issues as well as noise sensitivities. ‘Although it is still early days, the system has clearly solved the problems that were initially identified and appears to be a resounding success.’ The Conveni-Pack installation was carried out by WR Refrigeration of Leicester and commissioned by Daikin Airconditioning UK. Conveni-pack qualifies for Enhanced Capital Allowances.