Business Development Manager, AACS Limited
Delivering and maintaining a high level of indoor air quality has never been such a high priority. This is because long-term exposure to air pollution can cause or exacerbate chronic conditions, such as cardiovascular and respiratory diseases, as well as potentially affecting a person’s mental health and well-being. While there are numerous factors that contribute to the creation of a pleasant, clean and healthy internal environment, such as lighting, humidity, temperature and air quality, effective building ventilation is perhaps the cornerstone of good building health.
Fundamentally, ventilation aims to remove stale indoor air and replace it with ‘fresh’ outdoor air. Ventilation systems are designed to extract water vapour, airborne pollutants (from both inside and outside pollution sources) and odours, control humidity and maintain good indoor air quality.
In order for a building ventilation system to be truly effective and perform as the original design intended, it has to be commissioned correctly, and have a regular maintenance and cleaning programme in place.
Air pollution from both outdoor and indoor sources represents the single largest environmental risk to health globally” - World Health Organisation (WHO)
Installation and commissioning
It is crucial that the system is installed according to the manufacturers’ recommendations and commissioned in line with the final design specification. While last-minute changes during on-site installation, such as varying pipe lengths, for example, may seem minor, it can in fact have a significant impact on the system’s overall performance and energy efficiency. Consequently, this can also affect the building’s indoor air quality. That’s why it’s so important to use an experienced installer, who is approved to install the chosen manufacturer’s ventilation system.
Maintaining your ventilation system
Once ventilation is installed and commissioned, regular maintenance is essential in order to ensure the system continues to deliver a high level of performance, and this should form part of the building’s overall HVAC service regime. It is not a case of simply installing the system and then forgetting about it.
Given the system’s role of extracting airborne pollutants and providing a continuous supply of ‘fresh’ air, regular cleaning of a building’s ventilation is particularly important, as build-up of dust and dirt can affect the system’s ability to maintain indoor air quality. While HVAC units are fitted with filters, primarily to keep the system free of dust (as well as removing particulate matter from supply air), there is still more that can be done.
For example, regularly checking the supply intake and exhausts for signs of dirt build-up, pollution or contamination, or damage from weather or animals is good practice, as is inspecting the ductwork and indoor units. Any dust should be removed from the ductwork, with particular attention to the filters, heating and cooling coils and any change of direction in the ducting.
It is also recommended that on a regular basis filters are cleaned and replaced, indoor units are cleaned and the dust boxes of those fitted with auto-cleaning systems emptied.
For further guidance, BS EN 15780: 2011: Ventilation for Buildings. Ductwork. Cleanliness of Ventilation Systems specifies acceptable cleanliness levels for supply, recirculation and extract air, grouped into three classes – Low, Medium and High – depending on the use of the internal space.