Coltraco Ultrasonics is hugely indebted to Professor Catherine Noakes OBE for her initiative in establishing 8 November as World Ventil8day and we are privileged to join her, and all others, in celebrating this vital aspect of building performance annually. As Covid-19 settles into its fate as an infectious endemic disease like ‘flu or the common cold, we must all recognise the importance of improved ventilation in buildings. Society wide improvements to ventilation to prevent the spread of Covid-19, could end up stopping most other airborne ailments, and if this is taken seriously, buildings, in particular hospital buildings, will need to increase “air changes per hour,” to continuously replace contaminated and infected stale air, with pure fresh filtered air.
Professor Catherine Noakes OBE paved the way for our understanding that Covid-19 is an airborne virus. When the virus is exhaled in small respiratory droplets (aerosols) in indoor environments, the water content quickly evaporates because of the lower relative humidity indoors than outdoors, leaving viral particles suspended in the air. That insight in turn led to the knowledge that replacing the stale, contaminated, and infected indoor air with fresh or filtered outdoor air (air exchange) can help dissipate viral particles, that would otherwise linger for hours, super spreading the virus, which is essentially an indoor air crisis.
A significant number are still dying from Covid-19 although the good news is that this pandemic will fade due to effective vaccines, infection induced herd immunity, and the further evolution of the virus. The bad news is that like seasonal influenza, Covid-19 variants may be with us for many years to come, and this will certainly not be the last respiratory virus pandemic. We must think clearly and scientifically about how better we can reduce the spread of viruses in hospitals, especially when and where masks and PPE might no longer be in common use. Ventilation, natural or mechanical, is the main way that the risk of airborne infections in buildings is reduced, and the recommendations include increasing air changes per hour. To achieve this level of human air hygiene hospital buildings must be airtight, to ensure that there is no unwanted air infiltration through gaps and cracks in the building envelope and in the compartments within the building.
In all buildings, new and old, there will always be joints cracks or gaps in the walls and floors, windows and doors, or openings to allow for service penetrations to pass through, including pipes, cables, and ventilation systems. Where these spaces are not sealed, fire and smoke, as well as airborne diseases, will spread throughout the building. Acoustic insulation will be degraded, as will thermal comfort. Mechanical ventilation will be less efficient and air filtration might not be effective. Once all these leaks have been detected, located, and quantified, fixing and sealing them involves installing tested products to achieve compartmentation, such as pipe collars, intumescent seals, and many other low-cost closures. The challenge is to have the capability with which to detect with microscopic accuracy, to measure in terms of size micro air leaks, and to quantify each individual air leak site by precisely predicting the air flow rate through it. To be able to do this frequently and regularly, non-invasively and whilst the building is still occupied.
As part of the UK Government’s Emergency Response to the Covid-19 pandemic, Coltraco Ultrasonics won an InnovateUK/UKRI award to research how micro air leaks could be detected and located in NHS Hospital Wards where negative and positive air pressure ventilation techniques were being used to influence internal air flows and to prevent infection contagion throughout the hospital building. During our long history in watertight integrity monitoring for the Royal Navy we had learned that it was one thing to be able to identify large and microscopic leak sites, but that this alone will not however quantify the flow rate through each leak site. It is quite another to quantify the identified leak site through the structure concerned to determine the water flow rates, which is critical information to determine damage control risk overall in a ships’ watertight compartment, watertight door, or watertight multiple cable transit area between bulkheads.
With this understanding of fluid dynamics at sea, and our technology is used on 10,000 ships, about 17% of the worlds shipping fleet, our research for the UK Government was independently rated by InnovateUK/UKRI as outstanding. By using our understanding of fluid dynamics at sea and applying this to air flow dynamics on land, taking the best ultrasonic technology in Coltraco hardware to identify leak sites, with a microscopic level of accuracy, and applying computer science to measure and to quantify the leak site by its algorithm, we successfully invented an instrument which also generates the air flow rate and air permeability factor of individual air leak sites. From these humble origins and the development of the Portascanner™COVID-19 we then continued with our own research and development at our own commercial risk, to develop the Portascanner™AIRTIGHT.
The ability to record and to analyse these 4 factors, detect, locate, measure, and quantify micro air leaks make the Portascanner™AIRTIGHT unique and it complements the mandatory methods of testing for airtightness such as the “Door Fan Blower Test,” and the “Pulse Test,” before, during and after the execution of any build programme, as no pressurisation is needed. The Portascanner™AIRTIGHT is a British manufactured lightweight and handheld analytical instrument. It has been designed during COVID-19 with the support of Emergency Technology funding in 2020, and it builds on our unique ultrasonic understanding of fluid dynamics for the Royal Navy to deliver the Safeship™ at sea, to now enable the Built Environment to monitor and analyse the airtightness of buildings, and to deliver Safesite™ on land.
We celebrate World Ventil8day with a brilliant example of UK Government successfully supporting UK Companies to invent, and to develop innovation, which in turn becomes high-exporting, and this is now contained in the following UKRI video released last month. Our technology also helps to identify the points of energy loss in the Built Environment, in our capacity as part of His Majesty’s Government Net Zero Heat Cohort.