Launched last October, the Government’s Green Deal initiative is aimed at helping UK home owners look for ways of decreasing their energy bills while increasing the thermal performance of their homes. It also aims to reduce carbon emissions and raise the energy efficiency of the UK’s ageing housing stock, with the ultimate goal of helping to meet the UK’s carbon targets in 2050. The Green Deal refurbishment programme should make UK homes more energy efficient, but as Lee Nurse, Marketing Director at Vent-Axia explains, ventilation is an important accompaniment to improved heating and insulation, and this is creating huge opportunities for retrofitting work:
Under the Green Deal, energy bill payers obtain energy efficiency improvements, such as loft insulation, solid wall insulation and new heating systems, without having to pay up immediately. Instead businesses provide the capital, and they obtain their money back over time via the customer's energy bill. Central to this strategy is the 'Golden Rule' - that the estimated savings on the bill will always equal or exceed the cost of the work.
With domestic applications, the energy efficiency measures offered as a Green Deal package are based on heat loss and don't incorporate an air pressure test to establish the energy efficiency of ventilation. This means that despite continuous single room heat recovery offering energy efficient ventilation that recovers heat, its benefit is difficult to measure. As a result it cannot meet the Green Deal's 'Golden Rule'. However, if you insulate a home without improving ventilation it can result in condensation and mould.
Balance:
According to the Royal Institute of Chartered Surveyors, one in five UK homes are affected by condensation and mould growth. Evidence has also shown that if care is not taken to ensure adequate levels of ventilation, in line with Part F of the Building Regulations, then high levels of humidity can lead to a growth in dust mite populations, potentially resulting in health and comfort issues.
Meanwhile, figures from the European Federation of Allergy and Airways Diseases Patients' Association, state that poor Indoor Air Quality (IAQ) is responsible for two million otherwise healthy life years being lost annually across the EU. With the European Union planning a review of all IAQ legislation this autumn, the issue is likely to gain a higher profile.
Without understanding and minimising potential risks during energy efficiency work, the problems outlined above could actually be made worse. It is therefore important to ensure that a holistic building specification approach is taken with the overall objective of creating an energy efficient re-furbished building that has an ideal balance of heating, insulation and ventilation.
Indoor air quality guidance:
BEAMA has sought to address these issues with its new indoor air quality guidance for the UK's Green Deal Programme. The document, entitled 'Avoiding Indoor Air Quality Problems Associated with Fabric Improvements', clearly explains the health risks associated with poorly ventilated buildings and challenges Green Deal Providers to specify continuous ventilation with insulation packages to ensure good indoor air quality.
Kelly Butler, Marketing Director at BEAMA explains: "Continuous ventilation is a simple solution to air quality problems. We have met a number of Green Deal providers to make clear to them that by not addressing ventilation adequately when renovating homes they are putting the building and the occupants at risk."
If ventilation is not considered when improving the air tightness of a dwelling as part of an energy efficiency package Green Deal Providers and installers may face reputational risks and remedial costs.
"Obviously we see reputational risk here for providers of Green Deal measures and given that a simple continuous fan consumes less than £5 of energy per annum, this is a small price to pay for healthy living. We are delighted that DECC has highlighted the importance of ventilation in their own guidance for Green Deal and our document further outlines the risks and solutions available," adds Kelly Butler.
Risk:
Continuous Decentralised Mechanical Extract Ventilation (dMEV) systems, such as Vent-Axia's Lo-Carbon Centra, are an effective way of improving a building's ventilation and air quality. Designed to work with the natural air infiltration, continuous ventilation systems control the air path through the home. They prevent the migration of damaging humidity and pollutants, provide near silent energy efficient ventilation, and are ideal for retrofitting.
The latest continuous fans also offer heat recovery. There are now single room heat recovery units available, such as the Vent-Axia Lo-Carbon Tempra, which can be simply retrofitted through a 100mm diameter hole in the wall allowing standard 100mm bathroom, kitchen, toilet or utility room extract fans to be easily replaced.
This type of unit is capable of recovering any heat from extracted air and returning it back to provide up to 80% heat recovery. This performance, taken together with an integral Lo-Carbon DC motor with unique twin impeller design means the units consume as little as 2 Watts of energy and operate almost silently on trickle setting at only 20dB(A), delivering significant energy savings and reducing a property's carbon footprint.
In conclusion:
The Green Deal is an excellent opportunity for UK households; however without a properly balanced package of improvements problems can occur. It is the responsibility of the Green Deal Installer to ensure that the products installed are properly integrated with each other and with any previously installed energy efficiency improvements. As long as the work is carried out correctly, the home's energy efficiency will be improved, the building's fabric will be maintained and any health and safety risks for the occupiers will be minimised. Finally, the reputation of the Green Deal Installer will remain unblemished.
BEAMA's guidance document 'Avoiding Indoor Air Quality Problems Associated with Fabric Improvements' is available free to download at www.beama.org.uk.
Providers, assessors and installers need to apply to be on the Green Deal register, giving the seal of approval to businesses that successfully go through the authorisation process. Installers should sign up now to the Green Deal Register at www.gov.uk/become-green-deal-business.
Full guidance can be found in the Department of Energy And Climate Change document - Green Deal Code of Practice at www.decc.gov.uk/assets/decc/11/tackling-climate-change/green-deal/6533-green-deal-code-of-practice.pdf
To see a graphic of the Tempra heat exchange process, and another one showing the natural air change rate from a building having a particular leakage rate, please click on the download links near the bottom of this web page.
