Harmful chemicals in the air kill an estimated 29,000 people a year, with public buildings built near busy roads exposed to a high volume of these airborne toxins. A report by the Commons environmental audit select committee assessing air quality in schools was issued at the end of 2014, warning that no new schools should be built near areas with heavy traffic. For schools already in highly polluted locations, air filtration should be used to “protect children’s minds from toxic fumes”.
Fumes from factories and diesel cars have raised air pollution to dangerous levels in 16 British cities, leaving the country facing £300million in EU fines and legal action by the European Court of Justice. The problem was illustrated in April 2014 when a thick smog enveloped parts of the country, forcing schools to keep pupils inside.
The select committee’s report stated that the situation has become so bad that the way in which our cities are designed must be altered. Buildings that play host to lots of young, elderly or sick people should no longer be built in the most polluted sites. Building regulations should also be changed so that any existing school within 450 feet (150m) of a major road – of which there are more than 1,000 – has be fitted with air-filtration systems to protect children from traffic fumes.
The filtration of air and consequent maintenance of the systems that allow this to happen is essential and this can have a knock-on effect on energy efficiency and therefore utility bills – a win-win scenario. In fact, figures published by the Carbon Trust in 2012 put UK schools in the spotlight as a sector with the greatest potential to reduce energy costs. According to the report, our schools could reduce energy costs by around £44 million per year, which would prevent 625,000 tonnes of CO2 from entering the atmosphere.
In a busy environment, maintenance often falls by the wayside, only being addressed when things go wrong – a false economy. A study carried out by Johnson Controls highlighted the fact that best practices in building maintenance and operations can reduce HVAC energy usage by 10 to 20 percent, with poor maintenance increasing energy usage by 30 to 60 percent.
This is particularly key for air-filtration systems. Airborne debris – such as dust and autumn leaves – can clog filters and coils, therefore reducing flow rate. In fact, according to the same Johnson Control’s study, when condenser flow rate is reduced by 20 percent in mechanical and absorption chillers, full load energy consumption is increased by 3 percent.
Filters require changing on a regular basis, with pre-filters lasting longer and requiring fewer changes – providing the strain on them can be reduced: it is important, however, that they’re replaced according to pre-determined maintenance schedules. Ignoring maintenance periods of increased debris (between spring and autumn) can cover or ‘face-load’ the filters, potentially causing static pressure inside the air-handling unit to rise, resulting in filter collapse.
If the filters collapse, unfiltered air could reach more expensive components such as final bag or high-efficiency particulate air (HEPA) filters, leading to premature replacement and unnecessary costs. If no form of final filtration is used, once airborne debris had passed the pre-filtering stage, it will enter a building, affecting air quality – which is not desirable within a school environment, particularly one where poor air quality has already been identified as an issue.
ECEX air intake screens, for example, fit externally to HVAC systems which intake air, preventing airborne debris from affecting the efficiency of these systems. The screens have been installed at a university where HVAC equipment was running inefficiently due to surrounding flora and fauna. As a result of the installation, they have reduced maintenance time and energy consumption has been reduced by around seven percent.
Jason Davis, ECEX W: www.airintakescreens.co.uk