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Rupert Kazlauciunas, Technical Product Manager, MVHR, Zehnder Group UK, considers the health reasons to make sure indoor air quality is good.
A growing awareness of the health implications of poor Indoor Air Quality (IAQ) is sparking changes within the building services industry as current air quality standards are considered as less-than-favourable.
Current standards prioritise the air-tightness of homes, as an attempt to achieve high-levels of energy efficiency, but without effective ventilation and filtration solutions being installed, these dwellings can present significant health risks to occupants. IAQ is a clear cause of concern due to societal and habitual changes, partly resulting from the convenience of modern technology and the move towards a more ‘online’ lifestyle, which has led to greater time periods spent indoors (and therefore greater exposure to indoor pollutants).
Aside from the resulting ‘inconvenient’ health effects, such as brain fog, headaches and poor sleep patterns, there are a host of serious long-term health risks that should not be ignored. Respiratory disorders, mental health issues, depression, dementia and even cardiovascular disease are all directly associated with spending time in air-tight buildings with ineffective ventilation and poor IAQ.
In addition, the drive for energy efficiency has led to increased risks of health complications that are associated with building’s overheating during warmer months, which comes with its own unique set of concerns.
How can building efficiency affect indoor air quality?
Air-tight buildings trap airborne pollutants inside, resulting in poor IAQ and leading to health complications. Perhaps unknown to the occupants, these harmful pollutants can originate from inside the home from certain building materials that release Volatile Organic Compounds (VOCs) and from everyday activities, such as cooking or using chemical cleaning products.
The effects of these indoor pollutants have typically been “underestimated”. According to recent research carried out in the United States of America, the chemicals in deodorants, hairsprays, cleaning agents and nail polish remover rival some vehicle emissions.
In addition, poor ventilation has a direct link to increased indoor humidity levels, leading to condensation build up and mould that if left untreated can cause structural damage to the building and impact inhabitants’ respiratory systems, causing asthma and other health complications.
Why has policy not changed?
Despite the need for improvements in IAQ regulation, energy efficiency remains the priority when it comes to current regulations. There are few measures to safeguard the health of people in residential properties and no commercial incentives for developers or landlords to act. Standards to assess air quality are in place but none have the pressure of a certified pass or fail function to ensure that they are adequately enforced. The latest government white paper on healthy homes may well address this issue (expected to be published late October 2018) but steps need to be taken quickly to ensure success.
In fact, some developers choose to install low-grade filters over more effective filtration, such as the ISO ePM1 >65% (F7) in our ComfoAir Q units, to avoid being penalised for poor energy efficiency. This highlights a serious disconnect between the steps taken to improve IAQ and the commercial focus on energy efficiency.
The individual pioneers
Zehnder has many proactive solutions to combat poor IAQ. We were delighted to see our whole house ventilation approach recently featured on an October episode of Channel 4’s Grand Designs. The featured property was designed to be airtight as it needed to be as hypoallergenic as possible, in order to be a safe and healthy environment for the owners’ children, who suffered from severe allergies, but also featured effective ventilation solutions. The project was devised and engineered to ensure a comfortable and healthy indoor climate throughout the year, using a Mechanical Ventilation with Heat Recovery (MVHR) unit.
The MVHR system, which was referred to in the programme as the ‘lungs of the house’, extracts indoor air from rooms to keep excess humidity, carbon dioxide and toxins at healthy levels. The extracted air is then run through a heat exchanger and has a world class efficiency of up to 96 per cent. The system also includes additional attributes such as adaptive comfort technology with modulating Summer Bypass, that adjusts heat recovery settings throughout the summer months. Fitted filters which remove pollen, carbon dust and other toxins from outdoor air and flow control to maintain ventilation rates even as the filters get older.
This case however is unfortunately not the norm, as larger developers regularly ignore the health benefits of designing dwellings in this manner.
What can be done?
As we concentrate on more decarbonisation of the grid, the focus needs to shift from energy savings to health. One solution would be to make digital sensors a mandatory requirement for MVHR units, to react to issues with poor ventilation, humidity, temperature and CO2 emissions. Constant volume motors would also be beneficial in maintaining minimum ventilation levels.
In addition, summer bypass and constant volume motors ought to have minimum standards enforced. Enthalpy cubes and filters should be subject to regulation, with credit given for controlled enthalpy cubes and simplified grades to reward high levels of filtration.
In order to give sufficient credit to the innovations that have been designed to improve IAQ, we would advocate the implementation of a pass/fail system that looks beyond energy usage and takes into consideration the steps being taken to counteract health risks.