Integrated VRV systems using heat recovery techniques can significantly improve the energy consumption of energy-intensive food retail applications, says Martin Passingham of Daikin UK
Food retailers are under enormous pressure to reduce energy costs and cut carbon emissions. Because of this, affordable and energy efficient refrigeration and climate control systems are vital, particularly integrated solutions for heating, cooling and refrigeration using heat recovery.
According to the Carbon Trust, by making energy savings of up to 20 per cent, the retail sector alone could cut its total spend on heating and cooling by £560 million annually. Food outlets are typically areas of intensive energy consumption, with multiple requirements for lighting, refrigeration, hot water and internal climate control.
Therefore a whole building approach to climate control requirements using heat recovery could make a dramatic difference to cutting energy usage. As well as reducing carbon emissions, this approach should logically also cut fuel bills and ensure suitable payback times on any capital investment, helping to improve the bottom line.
It is clear that improving energy efficiency, or cutting energy consumption cannot be achieved at the expense of customer comfort or food safety regulations.
This is where we think VRV technology can provide the answer. It is already renowned for being a highly efficient solution for integrating a building’s heating, ventilation and air conditioning requirements and is perfect for the retail environment.
Because the heat pump varies the refrigerant volume within the air conditioning system, to match precisely the building’s requirements at any moment, each area is able to continually maintain its desired temperature, thus avoiding fluctuations in the internal climate while minimising energy consumption.
As a result, the energy efficiencies that VRV delivers – typically COPs of 3 to 5 – are among the highest currently being achieved in the industry. Greater levels of efficiency still can be gained by using systems employing heat recovery.
VRV heat recovery systems have not been known for addressing the needs of refrigeration. However, advances in the technology mean it is now possible to incorporate refrigeration systems into a total climate control solution.
These VRV-based heat recovery systems provide refrigeration for display cabinets or cold rooms and use heat recovered from this process for space heating and hot water.
This recycling of heat – which would otherwise be wasted – dramatically increases energy efficiency and reduces the overall heating and cooling costs, as well as cutting the cost of refrigeration. The refrigeration system, such as CVP from Daikin UK, recovers waste heat from areas such as refrigeration systems or indoor units in cooling mode and diverts it to areas that require heat.
This free heat can be used to produce hot water, warm the store area or produce warm air at entrances requiring air curtains. Evidence shows that heat recovery air curtains can deliver energy consumption savings of up to 67 per cent compared with a typical electrically heated air curtain.
A well-known food retailer recently installed the CVP system at a store in North Yorkshire.
This shop had the same 1,000 sq m of floor space as another branch in Derbyshire, as well as similar load requirements.
The Derbyshire shop used a large condensing unit for refrigeration and a separate gas boiler system for heating.
The energy consumption for both the shops was measured over a 15 month period and it was found that the shop using the CVP heat recovery system used 34.8 per cent less energy than the one using conventional heating and refrigeration systems. The CVP systems also saved more than seven tonnes of CO2 compared with the traditional system.
It is evident from these results that combined systems such as Daikin’s CVP can offer a complete solution for refrigeration, heating and cooling, while also minimising the environmental impact of a food outlet’s refrigeration requirement.