8 minute read
Air apparent
30,000:
The number of new MVHR installations a year in the UK
Air apparent
The drive towards energy effi ciency has oft en come at the cost of air quality in the home, threatening human health and driving the need for mechanical ventilation. Installers have an important role to play in this – but have responsibilities too
By Rob Shepherd
In recent years the need for greater energy eff iciency within the built environment has driven the move towards low carbon-emitting structures. A far cry from the draughty buildings of yesteryear, modern homes are now designed to retain as much of their heat as possible in order to adhere to energy eff iciency legislation. With high energy prices, retaining heat makes sense from an economic as well as an environmental point of view.
Indeed, 2014’s amendments to Parts L and F of the Building Regulations tightened up the focus on energy eff iciency, and the former included a six per cent uplift in standards for new homes, compared with the 2010 version. It also introduced the Fabric Energy Eff iciency Standard (FEES), which focuses on the eff iciency of the fabric of a new home. “There is a drive to deliver a fabric-first approach to energy eff iciency, and this means increased air tightness and insulation,” says Michael Bates, associate product manager at Elta Group. “The drawback is that the natural infiltration of fresh air is reduced.”
Taking into account that each of us exhales between 10 and 75 litres of
Course of action
NICEIC now off ers a new competency qualifi cation for installers of domestic ventilation systems. The new assessment package has been mapped against the relevant National Occupational Standards (NOS) and has been approved by SummitSkills, the Sector Skills Council for the building services engineering sector.
It will assess installers against set criteria formed from the relevant NOS for the installation of domestic ventilation systems. The training and assessment programme runs over two days and comprises a theory and practical exam as part of the fi nal assessment.
“We have been working very closely with key industry stakeholders to ensure the assessment delivers a competent installer to meet the needs of the ventilation sector,” says Paul Collins, technical services manager at NICEIC. “Once installers hold the qualifi cation they can then apply to NICEIC competent persons scheme for ventilation so they can self-certify their work in England and Wales.”
For more information, or to book your place on the course, contact NICEIC Certifi cation on 0870 013 0389 or email traininginfo@niceic.com
carbon dioxide and 175 grammes of water vapour per hour, while a family of four produces between 10 and 15 litres each day through cooking, washing and breathing, it’s no surprise that air quality can deteriorate so quickly.
Welfare state
As well as potentially damaging the fabric of the building itself, a lack of proper ventilation can lead to a build-up of contaminants that have a detrimental eff ect on human health.
Peter Howarth, who specialises in allergy and respiratory medicine at Southampton University, has called for increased awareness of what is being termed toxic home syndrome.
“This occurs when individuals and families are exposed to a potent mix of airborne pollutants within the home arising from poor ventilation, causing respiratory and skin diseases to occur more frequently,” he says.
His view is backed up by a pan-European study, carried out by the National Institute for Health and Welfare, which highlighted the impact of indoor allergens and found that exposure is linked to reduced life expectancy and greater likelihood of disease. Over half (57 per cent) of the cases linked to this related to cardiovascular diseases, 23 per cent to lung cancer, 12 per cent to asthma and the remaining eight per cent to other respiratory conditions.
Further research by Prism & Waverton Analytics confirms the health risks of poor indoor air quality in no uncertain terms. It found a staggering 91 per cent of homes tested for volatile organic compounds (VOCs) in the air were above the recommended level.
“As new and refurbished homes become ever more airtight, the number of people suff ering with asthma could almost double as a result,” says Ian Mitchell, product marketing manager for newbuild residential at Vent-Axia. “Current building regulations could also increase indoor pollutant levels equivalent to the upper end of – and in
some cases well above – World Health Organisation recommended limits.”
The most widely recognised technologies for dealing with the issue of poor air quality are whole house mechanical extract ventilation (MEV) and mechanical ventilation with heat recovery (MVHR). A well-designed system replaces contaminants with clean fresh air, and with the heat recovery it is also possible to keep over 90 per cent of the heat that would have been lost due to ventilation alone.
Yet despite the UK ventilation and air conditioning sector experiencing growth of four per cent in 2014, according to AMA Research, installations of MEV and MVHR have been relatively slow to catch on. The British Electrotechnical and Allied Manufacturers’ Association (BEAMA) has been working closely with NICEIC and industry leading manufacturers to highlight this issue.
“Currently, only two per cent of the UK have mechanical ventilation systems installed throughout their homes, which is concerning,” says BEAMA marketing director Kelly Butler. “We are aiming to ensure that housebuilders consider ventilation and indoor air quality at design stage rather than as a late add-on to specifications.”
Growing regulatory pressure means things are starting to change.
175g:
The amount of water vapour each person produces in an hour
“Specifiers, developers, engineers and self-builders alike need to achieve even lower Dwelling Emission Rate (DER) scores and greater Standard Assessment Procedure (SAP) ratings for new properties,” points out Jon Hill, technical manager at Polypipe Ventilation.
Case in point
But it’s vital any installation of such systems is carried out by qualified professionals; a message NICEIC is actively promoting (see box, page 33). Quite simply, the quality of installations across the industry can often leave a lot to be desired and there is a widespread lack of awareness about the importance of system design.
Kent-based NICEIC Approved Contractor Terry Baker Electrical Contractors saw the potential of MVHR in its infancy and has since completed many installations. “These need to be airtight systems and any leak will make the machine work harder,” says Richard Baker, the company’s contracts manager. “It is also important to take care when positioning the valves – the easiest position is not always the best. Inlet valves need to be put to the furthest position away from the door in the room to get a greater flow of air. Additionally, all modern machines need a yearly filter change and some sooner, depending on the location.”
Accuracy and attention to detail is vital, stresses Bates. “If ducts are carelessly installed it could lead to leakage and resistance to airflow, which would have an impact on the eff ectiveness of the ventilation,” he says. “The over-use of flexible ducting is also a key reason why systems do not meet design requirements, as it should only be used in very short lengths.”
Standard practice
It’s also important to use products that are able to perform to the highest standards. Vent-Axia’s Mitchell points out that the new Energy related Products (ErP) Directive, which came into force in January 2016, requires MVHR producers to meet minimum technology requirements. “These include an indication of the ventilation unit status being weeded out. Now there are some really good companies out there fitting MVHR systems – something that requires a trained person to do the job properly to protect the people in the property and the fabric of the building.”
As awareness of the issue of air quality in homes grows, we can expect to hear more about toxic home syndrome and the dangers it poses. It is up to the electrical contracting sector to play its part in ensuring ventilation systems are not only specified, but installed correctly as well.
Up in the air
Three high-rise blocks of fl ats in Smethwick, West Midlands, recently received a ventilation upgrade as part of an £11 million major refurbishment on behalf of Sandwell Metropolitan Borough Council.
The 270 homes, collectively known as The Croft s, are installed with Vent-Axia’s Lo-Carbon PoziDry PIV Compact ventilation units and Lo-Carbon Quadra fans, with the aim of improving indoor air quality, and reducing mould and condensation.
“Energy effi cient ventilation was an important factor in the refurbishment of The Croft s since the project aims to improve living conditions in the homes,” says Tony Davies of Sandwell Metropolitan Borough Council.
“Not only does this reduce the risk of health problems caused through condensation and mould, it also helps to reduce energy bills and carbon emissions,” he says.
that must be visible to the homeowner,” he adds.
It is estimated that there are now more than 30,000 MVHR installations a year in the UK, and The Zero Carbon Hub VIAQ Task Group even believes it will become the dominant form of ventilation in most new homes post-2016. This means that there are opportunities for electrical contractors to get involved, but those who neglect to undertake the correct training and skills development in this area won’t last long.
“MVHR is going to be a big part of the building industry in the future,” predicts Baker. “The good news is that the cowboys who jumped on the bandwagon to make a quick buck are » Rob Shepherd is a freelance business journalist who specialises in the building services industry
