Meeting climatic control demands

Martin Passingham, product manager DX at Daikin UK, looks at how technology has helped to advance climate control capabilities, making energy efficient VRV systems an alternative to traditional applied systems

Plug and play VRV systems have come of age - they are a real alternative to central plant and can now be used in larger buildings more than ever before. A system which has been expertly designed to match the occupants' building services needs will deliver climate control fit for a future in which energy efficiency is paramount.

Where heating, cooling, refrigeration and hot water might previously have been installed as separate services, the latest VRV systems integrate these into one system. A fully integrated system which incorporates all these building services can optimise energy efficiency and reduce carbon emissions, while simplifying operation and maintenance.

VRV's modular approach provides flexibility to balance heat loads in different parts of the building. The operation of a chiller system, by comparison, runs an entire system and requires an expensive backup unit. The modular design of VRV systems means that the risk of total system failure is avoided, eliminating the need for backup units. It also provides greater local control to meet the diverse range of requirements that large buildings typically have.

Upgrading to an integrated solution needn't be difficult to achieve when refurbishing existing building stock. For example, the latest generation of VRV systems from Daikin UK offer an easy to install solution that is also scalable. VRV IV heat pump and VRV III heat recovery systems can be added floor by floor as part of a phased refurbishment programme, thus spreading the cost of updates and minimising disruption to occupants.

System operation can also be customised to control varying heating and cooling requirements within different rooms or zones to prevent energy waste. VRV is therefore suitable for buildings which may have vacant areas and periods of high and low use.

However, to deliver a versatile system that also optimises energy efficiency, it's vital to analyse right from the start a building's multiple requirements, use patterns and varying occupancy levels. This enables engineers to specify a system capable of cooling one area of the building with the highest heat gains and transferring that reclaimed heat to other areas requiring heating or hot water.

For example, a typical building may require cooling down to 16°C and heating up to 21°C, with 200L of water storage being required for washrooms and 150L of water storage for kitchens. By recovering the heat when all indoor units are in cooling mode, a Co-efficient of Performance (COP) of 3.97 can be achieved. In milder conditions, when 75% of the indoor units are in cooling mode with 25% in heating mode, the efficiencies rise to COPs of 5.57. When the system is fully balanced between heating and cooling, efficiencies can increase to as much as 10.07.

Integration of a VRV system with the latest intelligent control can increase energy efficiency even further. Smart controls can also monitor energy consumption across a range of equipment, including air conditioning, to pinpoint areas of a building where the most energy savings can be made.

According to Franklin + Andrews, one of the world's leading construction economists, running costs for VRV heat recovery systems are up to £6.25/m2 of gross floor area. This compares favourably with a 2 or 4 pipe fan coil system, which can cost as much as £8.75/m2 and £10.75/m2 of gross floor area respectively - a 40 to 72% increase on running costs compared with a VRV heat recovery system.

Cost savings must be matched by savings in CO2 emissions as designers strive to meet ever tougher targets for emissions reductions in the years ahead. Stricter Building Regulations means that by 2019, all new buildings must deliver zero carbon emissions from the energy required for heating, cooling, hot water and lighting.

VRV systems offer a solution for all those designing heating, air conditioning and hot water systems to meet current and future legislation. Occupiers will enjoy a comfortable environment, with energy savings and carbon reduction