Back to the future: the potential for retrofitting

“[With retrofit,] an important factor to recognise is that no one size fits all,” says Rachel Shore, senior sustainable design consultant at renewable energy consultant Inbuilt.

“Requirements very much depend on who owns the building, the type of building and who occupies it.”

A good starting point is to consider how occupational comfort can be cost-effectively balanced with the building’s energy consumption.

Consideration should be given to improving existing building fabric and systems, rather than opting automatically to rip out and replace, advises Ms Shore.

“Often there will be a host of ways to reduce the operational energy requirements and improve occupant satisfaction with existing buildings by fabric upgrades alone,” she says.

Options include introducing natural systems back into the building, improving insulation and upgrading lighting systems and controls.

An insightful approach is also to give design teams an opportunity to interview existing occupants to identify the main points of dissatisfaction.

The ‘fabric first’ method is also recommended by mechanisms within the Green Deal and Feed-in Tariff consultations.

Once energy requirements have been minimised, the next point of call should be to analyse how refurbishment via a renewable energy installation could further reduce the carbon footprint of the building, thus continuing to reduce overall costs, says Ms Shore.

Integrated controls

Daikin UK engineering manager John Durbin says improving building performance through retrofitting is essential to meet legally binding carbon reduction commitments. Integrated environmental control and heat recovery solutions can make a major contribution towards this.

“At present, many of the UK’s buildings operate quite separate systems for heating, hot water production, air-conditioning and refrigeration,” says Mr Durbin.

“This means a huge proportion of the heat energy resulting from air-conditioning and refrigeration systems simply goes to waste, rather than being captured and used elsewhere in the building.”

By integrating climate control systems in an innovative way, a more holistic energy cycle can be created within a building.

Evidence shows that such solutions, which incorporate heat recovery techniques within a heat pump-based system, could cut energy usage by up to 60 per cent.

According to the Carbon Trust, heating and hot water production account for 60 per cent of a retailer’s energy bills, with refrigeration also making a major contribution.

“If we take a major department store, where refrigeration is required for cafés, restaurants and kitchens, it is easy to see how the high proportion of waste heat generated by this function can be re-used elsewhere in the building, such as for over-door air curtains or to provide hot water in washrooms,” says Mr Durbin.

“By using this holistic approach, it is possible to cut carbon emissions but also to make a real impact on running costs.”

Baxi specification channel manager Simon Osborne (pictured) says improving energy efficiency in existing homes is more difficult than in new build, yet is sure to yield far more effective results in reducing carbon emissions.

The challenge for specifiers is to identify solutions that offer the greatest opportunities to meet Decent Home requirements and solve fuel poverty problems, at the same time as helping to meet the UK government’s 2050 target.

However, the Technology Strategy Board’s Retrofit for the Future scheme provides examples of best practice in this area.

“Eighty-six social housing projects across the UK were funded,” says Mr Osborne.

“Each implemented ‘low-carbon refits’ of existing low-rise social housing that will meet the UK government’s target for reducing greenhouse gas emissions, while cutting energy use dramatically.”

Examples in the Retrofit for the Future scheme include listed properties and those in conservation areas where roof-mounted solar installations are ruled out.

These show that ease and speed of specification and installation are key factors to deliver more energy-efficient heating, Mr Osborne concludes.

Retrofitting and the NHS

Two recent examples of the potential of retrofitting for providing benefits for the client and business opportunities for HVAC firms add further weight to the argument for updating existing installations.

Canterbury Health Centre, run by the Eastern & Coastal NHS PCT, includes a doctors surgery and treatment centre where the plant was based around three ageing atmospheric boilers. Though well maintained, they were

suffering from age-related poor efficiency, encouraging the client to seek a better return on cost.

A full evaluation of the equipment installed was carried out by consultant Gibbs Dench Associates and the boilers were replaced by three condensing units. The resulting improved efficiency also enabled a reduction in size of the gas meter.

Variable head pumps were used on all circuits, reducing electrical consumption, and the domestic water systems were converted to mains pressure. The latter included high-recovery calorifiers of reduced capacity and electronic scale reduction units, one of which was recovered from the original installation.

The whole system, including valves, was then insulated to a high standard, minimising the often overlooked issue of heat losses from the associated pipework.

The second example is that of South Eastern Ambulance NHS Trust’s Paddock Wood Make Ready Depot. The project included the adaptation of a former light industrial unit, leading to a fully upgraded concrete structure to meet building regulations, including L2B for Energy Efficiency.

The result saw the provision of a full vehicle workshop using gas-fired radiant heaters, while logistics areas, operational offices and training facilities were served by a centralised ventilation system.

This included full heat recovery, augmented by a fully weather-compensated wet radiator system using condensing boilers and variable head circulating pumps and controlled substance close temperature controlled storage using DX heat pumps.

The entire mechanical services installation is now monitored and operated through a bespoke control system designed around a Trend IQ controller.

These two examples illustrate the aforementioned importance of considering the requirements of each individual setting, in order to ensure the most efficient solution is achieved to save energy and reduce carbon emissions. Both projects were installed by Delron Services, a multi-disciplinary engineering services contractor based in Maidstone, Kent.

A further example of energy-saving and carbon-reducing retro­fitting is that of Sony Group’s close co-operation with the British Standards Institute. This resulted in achieving carbon savings of over 1.7 million kg of CO2 and the meeting of regulatory and public requirements.

The project began in January 2011, when environmental and facilities representatives from 13 UK Sony companies agreed to work together to achieve the BSI Kitemark Energy Reduction Verification.

Sony became one of the first organisations to gain certification to the Kitemark Energy Reduction Verification (ERV) Scheme across its buildings.

One of the advantages is an improvement in the company’s position on the annual Carbon Reduction Commitment league table, with further positive implications for Sony’s tax contributions relating to carbon dioxide emissions.

The BSI Kitemark ERV Scheme was seen as an ideal way to verify carbon reductions and to present clear and independent information on energy use to the regulators. The scheme is based on the implementation of an energy management system.

Sony head of technical compliance Kieren Mayers says: “We are proud to have achieved the certification and now have a robust mechanism in place to respond quickly and accurately to the demands of the CRC Scheme.”

The ERV scheme has been approved by the Environment Agency as an Early Action Metric under the CRC Scheme, and means Sony is now able to verify the energy savings it makes, improve its position on the CRC Performance League Table and protect its corporate reputation.