Solutions for today and tomorrow
Rowan Crowley, Event Director for the forthcoming H&V07 and co-located RAC07 (NEC Birmingham, 27 Feb – 1 March 2007) examines the shows’ theme of Sustainable Solutions for the Future and focuses on a selection of exhibitors who will be addressing these issues.
Climate change is now starting to bite and the race is on to try to lower carbon emissions before it’s too late. Reflecting this urgency the Government is considering implementing a climate change bill in a bid to meet carbon emission targets.
However, this is just the latest instalment in an energy efficiency story that has been gaining momentum. A combination of tightening legislation and soaring fuel costs has meant the building services industry has been increasingly focusing on energy efficiency. It has been working hard to meet these challenges through the development of innovative low-energy products, new techniques and more environmentally sustainable approaches. Energy efficient products, such as solar heating and ground source heat pumps, are now moving centre stage with end users and industry alike recognising that as fuel prices continue to escalate sustainability is, and will continue to be, the way forward.
A now familiar low-energy product, the condensing boiler was thrust into the limelight a couple of years ago when the domestic heating market faced the huge challenge of converting its sector to the high efficiency technology. At this point, although the majority of new commercial boilers specified were high efficiency units many traditional boilers remained in larger, older installations since plant rooms were often built around the boiler, making retrofitting difficult. Expense was another problem since fitting a high efficiency boiler often meant replacing the whole system because condensing boilers could not cope with the accumulated dirt in old systems.
However, the introduction of the Energy Performance of Building Directive (EPBD), tightening of Part L and accelerating fuel prices has spurred on the heating industry to overcome these challenges. As well as producing compact and modular boilers to aid installation, manufacturers have also developed innovative flue arrangements to ensure condensing boilers are viable for older buildings. Meanwhile, the problem of retrofitting a new high performance boiler, such as the MHS Ultramax PB, to an old system, has now been solved thanks to the use of separator technology, where a plate type heat exchanger option kit can easily be incorporated into the boiler case to act as a barrier, protecting the boiler from the effects of dirt accumulation in older systems.
Until recently solar heating has been on the periphery of mainstream installations. There is a small but established market in the UK, with an estimated 70,000 domestic systems. However, renewable energy systems are now gaining ground in commercial buildings with solar and heat pumps emerging as the two most popular systems. In response to this Viessmann has launched the innovative Vitosol 300 vacuum tube collector which operates according to the heat pipe principle, this makes it suitable for both DHW heating and central heating back-up. Rather than the solar transfer medium flowing directly through the tube, a carrier medium, which evaporates with solar influence, circulates through a special absorber and transfers the heat via a heat exchanger to the solar medium.
Ground source heat pumps are another sustainable technology that is coming into its own with a small but growing market. Last year the total number of installations in the UK was estimated at 5 megwatt thermal (MWth) made up of around 600-700 units. However the DTI cites figures that estimate a rise as high as 10,000 units by 2010, 35,000 by 2015 and 55,000 by 2020.
In answer to this demand for ground source heat, innovative technology such as Rehau’s Raugeo geothermal systems has been developed which relies on harvesting ground heat via a system of probes and heat pumps. These use probes sunk at depths of up to 100m to harvest ground energy which is then extracted via heat pumps usually to an underfloor heating or cooling system.
However, some projects may not have the space, or the geology to use ground source heat.
An alternative technology is air source heat pumps. They work in the same way as ground source heat pumps except that the source of the heat is external ambient air. Coefficients of performance are likely to be lower than ground source heat pumps since outside temperature is more variable than in the ground. Although, the advantage of these pumps are the lower installation costs since no trenching or ground drilling is needed, instead the systems are often fitted to an external wall.
The new Viessmann Vitocal 350 AW heat pump uses air as its heat source; drawing heat from the air and transferring it to water. Its operation is simple. The heat pump, which can be sited outside or inside the building, passes large quantities of external air through an evaporator which carries refrigerant. The heat picked up by this evaporator passes through a scroll compressor and condenser and then to the water in the heating system.
In the context of increasingly demanding environmental legislation LoWatt DC motors look set to expand their share of the market for industrial, commercial and domestic fans. Mechanical ventilation faces the challenge of meeting both Part F and Part L which require fans to provide good air quality and energy efficient ventilation.
Across Europe, fan systems currently consume almost 200,000 GWh of electricity – an estimated 30,000 GWh in the UK alone. Besides cutting energy consumption by up to 50% LoWatt DC technology can more than double the working life of fans when compared to conventional AC drive meaning more efficient use of ever more valuable raw materials and less wastage of the manufacturing energy locked into products.
Another way to increase fan energy efficiency is on-demand ventilation which is designed for use in rooms used by a varying number of people at various times of the day. This type of ventilation system responds to the exact ventilation requirements of a room at any one time, supplying or extracting when and to the level required, therefore using only the energy that is necessary.
Vent-Axia has launched one such system called the Sentinel. Triggered by people entering or leaving rooms or by the atmospheric conditions in the area, automatic sensors and controllers manage the Sentinel according to maximum demand requirements of the building zone.
With the fast-approaching phase-out of HCFCs, and continuing question marks over the long-term future of HFCs, still exercising industry minds, the air conditioning market is facing a huge environmental challenge. With air conditioning accounting for over 30% of annual electricity consumption in a typical office, specifying an energy efficient chiller is a good place to start. When comparing chillers it is important to consider each unit’s Energy Efficiency Ratio (EER) which is the ratio of cooling output compared to power input. However, since a chiller rarely operates at full capacity throughout its life cycle it is also vital to look at a chiller’s ESEER (European Seasonal Energy Efficiency Ratio) as set out by Eurovent. The ESEER is the chiller’s performance ratio which compares power input to cooling power output at partial loads, therefore giving a more realistic view of the chiller’s life-cycle performance.
For end-users major investment decisions are now strongly influenced by energy prices, environmental laws, and the likely future direction of government policy. With this in mind low-energy products and approaches will be the only forward.
If you are interested in Sustainable Solutions for the Future visit H&V07 and the co-located RAC07, the UK’s only dedicated event for the refrigeration and air conditioning industry, (NEC, Birmingham, 27 February-1 March 2007).
The event will embrace cutting-edge sessions in the seminar programme reflecting the industries growing concerns with climate change, energy usage and environmental issues. These will be complemented by practical presentations in the Skills Centre and a constellation of the latest low energy technology and products on exhibitors’ stands.