The drive to improve the thermal efficiency of buildings has meant homes are becoming increasingly airtight. Whilst this may reduce energy bills for tenants, it can have a negative effect on an occupant’s health. Here, John Kelly, Marketing Manager at Airflow Developments, offers an overview of the issues currently faced by social housing providers and how the correct ventilation specification can protect both health and home.
With the adoption of the Decent Homes Standard, many social housing providers have invested heavily in improving the levels of insulation and the quality of windows in their homes, in an effort to improve the living conditions of their tenants.
And whereas these upgrades can hugely benefit tenants in terms of thermal comfort and reduced fuel bills, they also mean that homes are becoming increasingly airtight, which can have a detrimental effect on indoor air quality, if ventilation is not properly considered.
With people spending an estimated 90% of their time indoors and over 900 pollutants found within British homes, it is critical that high-quality indoor air is achieved within dwellings. As such, social housing providers have a duty of care to tenants in ensuring effective ventilation is in place once a building has undergone a refurbishment.
Without an effective ventilation system to extract excess moisture and polluted air, damp and mould can spread quickly throughout a property. This is particularly an issue in bathrooms and kitchens where everyday activities, such as washing and cooking, can cause excessive moisture to occur. If not adequately addressed, mould can develop that leaves unsightly and unpleasant marks on ceilings and walls – leading to time-consuming and costly remedial work.
Perhaps more concerning than the effect poor indoor air quality has on the fabric of a property is its consequences on occupant health. It’s estimated that over 15.3 million homes in the UK are at risk of Toxic Home Syndrome – a condition in which an occupant’s health deteriorates as a result of poor air quality within the home.
The dangers of Toxic Home Syndrome have recently been brought to light by joint research published by the Royal College of Physicians (RCP) and the Royal College of Paediatrics and Child Health (RCPCH). The report highlights the long-term effects of poor air quality on a person’s health and suggests that major health conditions such as cancer, asthma, heart disease and even obesity can all be linked to poor air quality. With this in mind, it is crucial that social housing providers take affirmative action to protect their residents.
When refurbishing a property to a standard that is notifiable to Building Control, social housing providers need to ensure that the work carried out will ensure the dwelling meets the minimum standards set out in Approved Document F1, Means of Ventilation. This ensures that excess moisture created through every day living like breathing; cooking; washing and indoor air pollutants arising from textiles, furniture and aerosols – which are potentially harmful to both occupants and the fabric of the building – are properly extracted.
As such, social housing providers should pay particular attention to the Domestic Ventilation Compliance Guide accompanying Approved Document F1 for the required extract ventilation rates for common ‘wet’ rooms which require enhanced ventilation. These rates are:
- Toilets: 6 I/sec (22 m3/hr)
- Bathrooms: 15 I/sec (54 m3/hr)
- Utility rooms: 30 I/sec (108 m3/hr)
- Kitchens adjacent to hob with a ducted cooker hood: 30 I/sec (108 m3/hr)
- Kitchens without a ducted cooker hood: 60 I/sec (216 m3/hr)
What are the options?
Central Extract Ventilation is a continual form of extract ventilation. Ideal for residential properties, a centrally mounted unit is typically installed in a loft space or cupboard and ducted around the home to each wet room.
Localised versions, known as de-centralised Mechanical Extract Ventilation (dMEV) units are also available. These single room fans can be mounted in wet rooms, such as kitchens and bathrooms for constant extraction.
One example, Airflow’s iCONstant fan, is unobtrusive and extremely economical to operate, with annual running costs being as little as just over £1 per year when used on its lowest speed. This continuous solution utilizes the very latest motor technology boasting features that reduce human intervention whilst ensuring the fan is always operating at its optimum level.
For those not seeking continuous ventilation, intermittent extractor fans operate on an ‘as required’ basis. Manually operated via a pull cord or switch, or automatically by timer, humidity or motion sensors, these fans are ideal for kitchens and bathrooms.
One such fan, the Airflow QuietAir, is designed to provide powerful extraction levels that exceed the requirements of the latest Building Regulations. Featuring noise levels as low as 25 dB(A) and a specific fan power (SFP) of just 0.24 W/l/s, the QuietAir is ideal for the social housing sector where specifiers, landlords and tenants all seek a ventilation solution that is energy efficient, economical to run and quiet to operate.
An alternative intermittent option is the Loovent – a highly reliable and powerful centrifugal fan in a modular design for ease of installation. Offering an adjustable timer overrun control, the Loovent provides efficient ventilation in removing damp moist air, odours and airborne pollutants from en-suites, bathrooms and utility rooms.
Some ventilation manufacturers may claim that products comply with the latest Building Regulations, however in some cases the proposed performance might only be in regard to a free air environment. If the added resistance of ducting and/or grilles has not been taken into account for a fan that has been installed, its performance could drop below the minimum required level for it to comply with Approved Document F. Therefore, a fan may not perform to the required standard when installed as part of a system, which could mean that even though a ventilation system is installed – there could still be a build up of pollutants and moisture.
When specifying a ventilation system, social housing providers need to check the product’s installed performance data; paying particular attention to the fan’s performance graph, known as the ‘fan curve’. These graphs show the flow rate against the static pressure, providing specifiers with a greater understanding of the installed performance.
To ensure the fan meets installed performance, a Powered Air Flow meter should be used to check that the extractor fan is fit for purpose. These instruments use an inbuilt fan to equalise the back pressure of the measuring device so that accurate air flow measurements are possible without further complex calculations. To ensure compliance, this should always be carried out on-site by an assessed and registered ‘Competent Person’ who has completed and approved ventilation installer course, such as NICEIC training.
As thermal comfort becomes an issue of increasing importance for social housing, it is critical for providers to ensure these targets are met without compromising the health of tenants. When refurbishing existing properties, specifying the newest technology whilst ensuring installation is carried about by a verified installer can ensure that a property’s interior appearance is not affected by damp and stale air, as well as taking crucial steps towards protecting properties from Toxic Home Syndrome.
For further information on Airflow, please visit: www.airflow.com or follow @airflowD