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Achieving Passive House Levels of Airtightness with the Portascanner™ AIRTIGHT.

Enhance Human Health, Planetary Health, and Building Health with a micro air leak detector will save you time and money, by ensuring that you will pass the mandatory pressure test, first time and every time. Check for airtightness at every stage of the build programme.

1. Human Health.

Covid-19 has been the first global pandemic in history, to have affected the entire world population. The last 3 years have shown that enhancing Indoor Air Quality (IAQ) to be as effective in reducing aerosol transmission of viruses, as vaccinating 50-60% of the population. Landlords and business owners are now challenged with optimising the operational performance of their buildings to the greatest extent possible, in conjunction with the enactment of behavioural change to minimise risk and to give occupants peace of mind. With significant links to cognitive function and risk of disease, historic efforts regarding indoor environmental quality, have typically focused on volatile organic compounds (VOCs), and particulate matter. However modern threats have led to a broader focus, encompassing humidity, temperature, and lighting, all of which play an important role in determining virus survivability, immune system health, and infection potential. 

We must not lose sight of the unique nature of buildings, for example increasing natural ventilation might be a sound strategy for some buildings at certain times of the year, but could create poor temperature and humidity in another, leading to a reduction in immune system health and an overall increase in viral transmission risk. At present air quality has a direct and wide impact upon society. Understanding how biological contaminants and viruses can rapidly build up indoors, in the context of human health and user comfort has become more relevant since the Covid-19 outbreak, to protect the health and well-being of a world population of which 70% spend 90% of their lives in a building. Place people in a poorly ventilated room, where coronavirus containing aerosols are trapped in the air with nowhere to go, and their risk of getting Covid-19 skyrockets.

You can decrease the risk by ventilating the room and filtering viruses from the air, but you must have an airtight building with airtight compartmentation to do this effectively and efficiently. To achieve this with certainty, you must use a micro air leak detector.

2. Planetary Health.

The Construction Industry contributes up to 40% of global carbon emissions and the total area of additional floor space in the world will double in the next 30 years. It is daunting to see how we can affect the industry anytime soon. But we can make a difference with one building, one strategy (Passive House) and one choice at a time. The cheapest energy is the energy which we do not use and by improving the insulation, airtightness and heating and cooling sources of our buildings, we will have warmer or cooler and cleaner places in which to live and work.

We are also being kinder to the one planet we all share, and Passive House’s exponential growth comes as no surprise. Great design and specifications give us a better-quality building with a smaller carbon footprint. However, whilst designing new build is exciting, we must accept that over 80% of the buildings which exist today will still exist in 2050 and well beyond. Much of our work is now going to include retrofit and assessing which buildings might have to be demolished and rebuilt, and where retrofits are the better choice. Operational data from occupants will not always be available as some of these buildings might not be occupied, and the data you need, you are going to have to generate yourself.

Surveys are going to have to be thorough and the more accurate the data you have access to, the sharper your decisions. Retrofits are challenging. But in a resource depleted world and where both operational carbon emissions as well as embodied carbon emissions must be reduced, we need to save as many buildings as possible, and to explore cost effective, regenerative retrofits. Thermal comfort cannot simply be procured in the form of mechanical equipment alone. This is why the notion of electrify everything is misleading. If your walls and windows are cold, you are going to lose radiant heat and occupants are going to feel cold.

Ten years ago, Allison A Bailes II wrote, “Many architects don’t get it (they will insist that you need more equipment) and the clients don’t get it. And since there is always someone who will talk up the comfort potential of a smart thermostat or radiant floor, it is hard to convince people that it really is about the quality of their wall or window.”  To achieve a low carbon, high comfort building for the same price as a conventional retrofit does mean that we must change the way we work. The Portascanner™ and the Portascanner™ AIRTIGHT can be used as diagnostic instruments to collect critical data in deep retrofits. By conducting regular airtightness checks throughout the build programme, you will know what air permeability values you are achieving, and you can approach the pressure test with the confidence of a first-time pass. Many deep retrofits sometimes include as many as 8 to 10 air pressure tests, and the leaks are found by a slow and expensive method of elimination. There is now no need for this.

3. Building Health.

The definition of a healthy building by The World Health Organisation is: “A space that supports the physical, psychological, and social health and well-being of people.” Whilst this is true, there is no mention of the health of the actual building itself. Today the value of buildings is intrinsically linked to their energy efficiency and actual building health levels. We all understand the former, but only a few understand the latter. The few that do are those who aspire to close the performance gap, and who accept that a high level of airtightness, complemented by either controlled passive or mechanical ventilation, or more likely a hybrid solution, is necessary.

Some other benefits of well-ventilated airtight buildings include thermal comfort, acoustic insulation, energy efficiency, pest and infestation control, prevention of water ingress, rot, mould, condensation, and dampness, and importantly achieving fire suppression. Fire prevention in non-occupied buildings, where hypoxic environments can be created and maintained, is becoming relevant too.

Since smoke and toxic gases from a fire (which account for most deaths in a fire in a building) have similar sized particles as infectious virus particles, they will follow similar air paths. This connects our early work with the development of the Portascanner™ AIRTIGHT with our competency in fire suppression systems and room integrity, in particular Fire Doors.  Fire Doors have a dual purpose. Firstly, as a fire break to stop the spread of flame and to prevent the fire from taking hold, and secondly as a barrier to stop the lethal toxic products of combustion from killing people. We know that temperature has an influence on how smoke and toxic gases infiltrate through gaps and cracks in a building, and any gaps or cracks around a Fire Door, particularly in a tall building, or indeed in any other building near to the fire, will permit the lethal products of combustion to flow through the gap or crack and into the air beyond. Some methods of testing Fire Doors for gaps and cracks are unscientific, rudimentary, and inconsistent. It is generally accepted that to provide the required level of fire resistance, all Fire Doors should be reinforced with either intumescent strips or cold smoke seals or a combination of both. The Portascanner™ AIRTIGHT can be used frequently to check the integrity of Fire Doors and Flat Entrance Doors, with minimum disruption to the occupants of the building. Responsible Persons can now be compliant in this respect, with the Building Safety Act which recently came into force in the United Kingdom.


The quantification of air flow rates through individual leak sites as small as those with a diameter of 0.5 mm and being able to detect, and to locate with microscopic accuracy, individual leak sites as small as those with a diameter of 0.06 mm (invisible), are the innovative aspects of the Portascanner™ AIRTIGHT. There is no other commercially available device capable of quantifying the air flow rate from an individual leak site using ultrasound, not requiring any form of pressurisation. Checking airtight seals in industry, and in our everyday lives, provides more applications. This unique technology empowers trained operators to work smartly, and to be better, faster, and cheaper than all their competitors, in finding the leak, sealing the leak, and fixing the leak. It is the ideal instrument to ensure that you achieve your desired level of airtightness.

Author – Major Bernard Hornung

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