The Clean Air Act is often abused, misunderstood and, on occasions, blatantly ignored. But SFL sales manager Mandy Webb (right) believes installing the correct chimney or flue can save money, as well as protecting air quality
FOR global ecological reasons, air quality is a subject being treated as a high priority by many countries. Within the UK, legislation on this subject has been with us since the 1800s.
In response to the Great Smog of 1952, the Clean Air Act 1956 created zones where only smokeless fuels could be burned, and relocated power stations to rural areas. A further act in 1968 introduced the use of tall chimneys to disperse air pollution for industries burning coal, liquid or gaseous fuels.
Both of these acts were repealed and consolidated into the Clean Air Act 1993, which introduced a wide range of regulations on the height of chimneys and the content and composition of motor fuels.
The Environmental Protection Act 1990 established the main mechanisms for minimising air pollution from industrial sources. It has helped to improve air quality considerably, but continuing regulatory effort is important in order to maintain the improvements.
These mechanisms are now being replaced by systems introduced under the Pollution Prevention and Control Act 1999, which incorporate implementation of the EU IPPC Directive 96/61/EC. A phased approach is underway to apply the controls sector by sector, and is due for completion by October 2007.
As a result, when plant becomes redundant, it is replaced with
the most emission- and energy-efficient option available. In
combination with a building management systems, this strategy has proved to offer a significant reduction in fuel consumption and consequent savings in running costs.
SFL flues have been installed in Lothian and Borders Police headquarters, Edinburgh, as part of a refurbishment designed to upgrade the heating system in line with the force's energy policy.
Built in the 1970s, the original heating plant was due for replacement. The two oil-fired 1,000kW boilers had been converted to gas-firing but, after 25 years, had reached the end of their operational lives.
Consulting engineer Taylor Associates assessed occupancy patterns in the building, which operates 24 hours a day, seven days a week, with widely disparate manning levels. A modular boiler system was selected, using 12 condensing boilers. These provided a 12/1 turn-down ratio, to accommodate times of low demand and maximise energy efficiency.
Condensing appliances generally incorporate a fan to help move the flue gases through the secondary heat exchanger. This meant a chimney able to handle moisture in the flue and a slight positive pressure was required.
JRF Chimney Specialists, SFL's principal distributors in Scotland, was approached by the consultant to provide a solution and together they agreed a route and appropriate diameter for the new chimney run.
An SFL Europa chimney was selected with an inside diameter of 450mm to achieve the most efficient and cost-effective solution, as well as compliance with the Clean Air Act.
The Europa model installed is a twin-wall insulated stainless-steel product and the jointing method is such that there is no possibility of any leakage of combustion gases or condensate. This, the company says, makes it ideal for this application.
The multi-functional Europa system is designed to convey gases, particles, fumes, smoke and products of combustion, operating at continuous flue gas temperatures of up to 760˚C. It is a lightweight, engineered system designed to resist pressure up to 15kPa, and available in diameters from 100mm to 1200mm in various materials and formats.
A police spokesperson said: 'We expect to make major energy savings, in the order of 30%, because of the new equipment which has been installed during the refurbishment. The heating system will be largely responsible for the reduction in fuel consumption as the modular, condensing boilers are much more energy efficient than the plant they replace; previously, any demand for heat brought in a 1,000kW boiler.
'The building management system also makes a major contribution, and other energy saving measures include a combined heat and power plant and variable speed drives on pumps and air-handling units,' added the spokesperson.
Other chimneys and exhaust ranges include the Nova and SM systems and, in addition, SFL also manufactures single-wall systems, as well as gas and oil vents.
The new heating system offers the client the required improvements in efficiency, and the SFL Europa chimney is instrumental in allowing the high-efficiency modular boilers to operate at their maximum efficiency.