Considered approach needed to avoid indoor pollution
Jason Bennett, national Business Development Manager for service partners at Zehnder Group UK explains why effective building installation is critical for ensuring occupants’ wellbeing.
Ventilation technology has come a long way in the past 20 years. In the industry’s infancy and in its simplest form, a ventilation system was a fan in a box. Nowadays those box fans have evolved to be sophisticated pieces of innovative technology that need specialist knowledge for install and commissioning.
Digital controls, air flow calculations and zoning all need considered approaches in each building to be effective and can’t just be fitted by any tradesman.
But there’s a lot more to it than that. Understanding the reasons behind why these products are important and the effect they have on a building and the inhabitants inside will make the installer take a different view on what it is they are fitting into a building’s fabric.
Understanding the importance of indoor air quality
The current construction mandate is to tighten all our buildings in efforts to maximise energy efficiency and build more sustainably. This is important in our drive to meet net zero targets and make buildings more airtight through the use of triple glazing, insulation and creating a more robust, sealed-up building envelope.
However, by doing this, buildings lock in polluted air and as a result risk putting occupants at severe risk of bad health and this is where an effectively-installed ventilation system comes into its own.
Making a building more airtight doesn’t just stop heat from escaping. It prevents fresh airflow in and out of the property, meaning that natural ventilation and air leakage is restricted. As a result, dangerous pollutants become trapped inside. Without means to extract and change the air, particulate matter and harmful gases (such as CO2 and airborne chemicals) amass, creating a build-up of toxic air within the building.
Air pollution, both outdoor and indoor, is the most significant environmental health risk around today. According to the World Health Organisation, it is responsible for around one in nine deaths annually and will only get worse unless we take action to mitigate the risks.
Although air quality has gradually improved in recent times, air pollutant concentrations “still exceed the 2005 WHO air quality guideline levels in many areas” according to the WHO, meaning they are above the air quality guideline levels that are associated with important risks to public health.
It is widely known that indoor air can contain concentrations of pollutants up to five times higher than those found outdoors, so with almost 90% of our time spent inside, it is important to realise the risks and protect against this invisible threat.
When inhaled, the pollutants that are present in the building can get into the bloodstream and travel through the body, causing serious health problems with regular exposure. Chronic exposure has been associated with respiratory diseases and aggravating existing conditions like asthma and these pollutants can also lead to cardiovascular diseases. Prolonged exposure can affect the heart and blood vessels too, causing inflammation and oxidative stress, which could potentially lead to heart disease, stroke, and high blood pressure.
To create a healthy indoor climate, the indoor air therefore needs to be refreshed to extract the pollutants that people bring into the building. Occupants are told to regularly open windows or doors in the envelope of the building to refresh the air but of course that isn’t always an option.
Furthermore, as soon as the windows are closed again, and the building is still occupied, the pollutants start rising again. Studies showthat up to 60% of the time in a year, the air exchange is insufficient (with the CO2 value rising above 1000 ppm) through opening windows alone and could pose a health risk to those inside. Opening windows and doors also means that more energy is used to keep the rooms at the desired temperature, which goes against the energy efficiency objective.
An effective ventilation system install is therefore so much more than mechanics.
[sub heading] Achieving the best install
Part F of the UK Building Regulations mandates the performance of ventilation systems to achieve the desired inflow of fresh air and outflow of pollutants within buildings. At present, however, Part F only sets minimum requirements for the rate of fresh airflow into a building, in other words to ensure there is a sufficient supply of fresh air to push out pollutants.
It does not stipulate requirements for how that fresh air is circulated once it is within the building envelope and that is vital for an effective ventilation strategy.
In new buildings, the installation may be more obvious and straightforward, mapped into the building at design stage, leaving ample room for access, ducting and maintenance in the future.
However, when it comes to providing ventilation for older buildings, there are many more challenges to be faced. Unlike new builds, where ventilation requirements are specified to building regulations and mapped into the building system design, older buildings can be far less flexible and often the original purpose of the space needs to be a consideration for any new technology installation.
Be it a new build or building refurbishment, the correct installation of the ventilation system is essential. The results of a poor install can have serious detrimental effects on a building’s fabric, causing condensation issues that can lead to toxic black mould, excessive use of energy that drives up the running costs of a building and, most alarmingly, pose a health risk for the occupants inside through poor indoor air quality.
Bad airflow through a building also has a profound effect on overall occupant wellbeing as a result of extreme noise levels of the pressure through the ducting.
Yet we are seeing that this is happening across the industry and are finding all manner of tradesman, from pipework engineers to electricians, trying to install and commission ventilation products.
This is largely down to a significant skills gap within the industry. There are simply not enough specialist M&E contractors who are ventilation qualified and can do the job. If there was a true understanding of the impact of a bad install across the industry, the resulting benefits would be substantial.
With building regulations now putting more emphasis on ventilation performance and energy efficiency, a good understanding of ventilation practices has never been more important to provide a quantitative basis for designing, monitoring, and optimising ventilation systems, thereby contributing to efficient and effective operation in various industrial, commercial, and residential applications.
Without this knowledge and a good understanding of the building regulations for ventilation, the industry is falling short, with engineers who lack practical experience being made responsible for installing these complex systems.
Manufacturers are therefore making significant investments to upskill the industry and design units and components that make the install easier and more time efficient.
For example, solutions such as the Zehnder RapidLock connection clip for semi-ridged ducting can make installs quicker and easier for the technician while ensuring a secure, airtight connection across the air distribution system from the manifold to the grille housing. In fact, it can make the process three times faster for installation per household.
The purpose of such solutions is to remove complexity for installers and eliminate the need for grappling with metal clips, greasing gaskets or relying on bayonet sockets, even when ducting is rotated 90 degrees. A tight seal can be made in seconds and installers can confidently move onto the next task, knowing that the system is locked and working efficiently to protect the wellbeing of inhabitants in that building.
These streamlining solutions aid engineers in the installation process, enhancing opportunity for swift commissioning and hassle-free maintenance and cutting down the time on site. They also prevent problematic and unnecessary errors, such as damaged ducting, bad alignment or air vent leakage that are often mistaken as system faults rather than installation error. All of these can lead to various issues such as increased energy consumption, disruptive noise, reduced indoor air quality and uneven airflow.
At the end of the day, if installers can truly understand why indoor air quality and an effective ventilation system is essential for every building, they’ll ensure a best-in-class job every time.
