Foster Refrigerator believes that by taking a ground-up approach to developing its new cold store, it has maximised the energy efficiency potential. Andrew Gaved reports
Foster Refrigerator has developed what it believes is the most efficient cold store of its type, a benchmark it has achieved by looking at all parts of the system in turn.
The Foster Ultra is described as a ‘back to basics’ concept. As Foster’s cold store specialist Sam Devitt says: “For too long we have been focused on only the efficiency of the equipment being used. Now we have a complete solution.”
The company believes that the cold store market has too often historically been focused on low entry cost, rather than the ability to save the customer money and that a premium low-energy product has much to offer in terms of lifetime costs.
“Customers look too often at the price of the kit, not at the price of the stock inside,” says Mr Devitt. However, the company says it has seen a ‘dramatic increase’ in recent years of customers looking to spec on the basis of energy efficiency, as the energy cost of an element that runs 24 hours a day comes under the spotlight of company bosses.
Given the fact that the main point of the equipment is to store the maximum amount of stock within a limited physical area, a cold store design that can optimise the stock capacity while keeping performance high and energy low is something of a holy grail.
Foster thus set to work on optimising all the factors, using a working unit in its Kings Lynn factory to model ‘real world’ running.
The engine room of the cold store is the Ultra condensing unit, described as ‘ultra low energy’ and featuring a variable condensing temperature.
The Ultra is claimed to offer a significant 20-25 per cent improvement in energy than its predecessor and, Foster boasts, a 30-35 per cent improvement over standard condensing units.
The unit is, Mr Devitt says, simply much bigger than others in its class, with a microchannel heat exchanger for further efficiency. Additionally, the Ultra condensing unit features an intelligent controller that saves precious minutes on reaching temperature.
In turn the evaporator in the Ultra configuration incorporates EC fan technology for optimum energy efficiency.
In a further consideration of energy efficiency, the Ultra coldroom can be specced with insulation of up to 100 mm if required. “It is a question of optimising the space for product versus the insulation” says Mr Devitt.
Other features to improve the thermal performance include a semi-rebate door and camlocked panels for better thermal integrity, together with an insulated curtain as standard – a step up, Foster says, from the conventional PVC version.
The panels are sealed with four-way gaskets as opposed to the conventional single-strip closure. “A single strip simply doesn’t achieve the thermal integrity” warns Mr Devitt.
In addition, a self-closing door can be specified for those customers who want optimum performance – or who don’t trust their staff to shut doors themselves.
The ultra-low energy spec has spinoff benefits for maintenance too, resulting in lower service calls, he notes: “Customers are looking more and more at lifetime costing and the reduced cost of service callouts alone could be the difference.”
But as noted at the outset, the performance of a coldstore is more than simply down to the performance of the cooling equipment.
By redesigning the racking configuration, Foster claims to be able to offer 18 per cent more storage. In addition, a range of rack and storage options offer different ways for the customer to store more product, more efficiently.
The Ultra concept can be applied to any size coldroom, from 0.5 kW up to 15 KW, the company says, with the units built to customer spec.
The combination of a lower energy draw than standard coldstores and a lower run-time, thanks to the control protocol, adds up to significant running cost savings.
Foster’s testing has shown that a standard spec coldroom has a 20.21 kW average output and a daily run time of 20 hours, whereas the Ultra spec has a 17.57 kW output, but a run time of just 16.88 hours. On a 12p per kWh utility cost, this would provide savings of £90 a week.
When this is extrapolated to the 10-year lifetime of the plant, the savings amount to an impressive £39,000 saving. And to make the purchasing team event happier, such running costs equate to a two-year payback, Foster claims.