Domus Ventilation, manufacturer of market-leading ventilation systems that save energy and improve indoor air quality, has expanded its HRXE range of Mechanical Ventilation with Heat Recovery (MVHR) units with the launch of HRXE-ZEUS. HRXE-ZEUS has been introduced to meet ventilation requirements for large residential properties, which require a more powerful system to deliver the airflow required to meet Building Regulations Part F.


HRXE-ZEUS high performance MVHR system combines supply and extract ventilation in one system. Using an advanced heat exchanger, up to 95% of the heat typically lost in waste, stale air is efficiently recovered and used to temper the fresh air drawn into the building. The filtered, pre-warmed air is distributed to areas of the home such as living rooms and bedrooms, effectively meeting part of the heating load in energy efficient dwellings. The system features two independent fans which have full-speed control for background and boost ventilation rates.


HRXE-ZEUS comes with 100% thermal bypass which automatically activates when the air temperature reaches a pre-set level, allowing in cooler, fresh, filtered air without warming it through the heat exchanger – ideal for increasingly air tight properties that are prone to overheating in summer. The smart design of HRXE-ZEUS means there is no reduction in airflow when operating in bypass mode.


There are four HRXE-ZEUS models to choose from, available to meet different specifications and different on-site requirements, including opposite handed units and units with integral humidistat. Optimal ventilation performance is achieved when choosing models with the latter, as the sensors accurately measure air humidity and the HRXE-ZEUS’s extract speed automatically changes from background to boost as the level of humidity increases.


HRXE-ZEUS accessories include an Anti-Vibration tray which isolates the unit from the wall to reduce any low levels of vibration induced noise, condensation drain kit and, of course, replacement filters. The filters are easily replaced via the front access panel, for quick and easy maintenance.


HRXE-ZEUS joins Domus Ventilation’s existing range of MVHR systems, including HRXE-HERA which is suited to use in smaller properties of up to two/three bedrooms, and HRXE-AURA designed for homes of up to four/five bedrooms. All units are listed on the SAP Product Characteristics Database (PCDB) and come with a warranty of five years, with the first year covering parts and labour.


The HRXE range has been designed to work most efficiently when used with Domus duct systems, providing a total solution to whole house ventilation solutions for residential properties. Domus duct systems offer improved system performance through the exacting tolerances and engineered fit of the system, whereby pressure drops are minimised and air leakage virtually eliminated. Domus duct systems feature a range of unique products, including the award-winning Greenline Bend which reduces duct bend resistance by up to 60%.



Domus Ventilation has a well-deserved reputation for quality, supported by excellent technical support, from a market leading manufacturer and designer. It is well placed to offer immediate, practical solutions to Building Regulations Parts F & L.


For further information on the Domus Ventilation HRXE-Zues and MVHR appliances, CLICK HERE to email Domus Ventilation


OR HERE to visit the Domus Website



Track the invisible and make Indoor Air Quality a priority with the IAQ multi-sensor


The IAQ multi-sensor from Siemens Smart Infrastructure offers a key contribution to room automation with a simple insight into room conditions that helps to prioritise indoor air quality and create a healthy and productive environment.

The sensor tracks seven key environmental factors in a single wall-mounted unit: fine dust (PM2.5), volatile organic compounds (VOCs), carbon dioxide, relative humidity, temperature, light and noise (dBA). The IAQ offers the same level of accuracy as individual room sensors, with an intuitive colour indicator to identify air quality status. Transparency in air quality is further ensured through an easy-to-read LED display, with a simplistic design that offers clear and quick indication of air conditions. This simplicity is carried through to the touch-sensitive buttons which allow easy scrolling through the sensor’s parameters.

The unit assists building owners and operators in meeting a range of environmental building regulations and certification requirements including WELL, RESET, LBC, FITWEL and LEED.

In addition to monitoring the air quality, the noise sensor (no recording) can detect the number of people in a meeting room.

Studies have shown that poor ventilation can account for more than 50 percent of all sick leave with poor air quality also perceived to reduce work performance by over 9 percent. The IAQ is one of a range of products from Siemens designed to optimise indoor air quality which is some 2.5 times more polluted than typical outdoor air. This range also includes Connect Box, an open and easy-to-use IoT solution which manages small to medium-sized buildings and can be simply connected to operate with the IAQ via wireless or wired protocols (BACnet and LoRaWAN).

Ease of installation is ensured through the sensor being suitable for use with most commercially available recessed conduit boxes.

Working together, the IAQ multi-sensor and Connect Box offer a highly efficient monitoring solution to increase health and comfort in small to medium-sized buildings without the need of a BMS system.

CLICK HERE for further information on Siemens Building Products


CLICK HERE for further information on Siemens Smart Infrastructure



To meet the increasing demand for ventilation systems in the UK, leading indoor climate solutions manufacturer, Zehnder Group UK, yesterday opened a new modern manufacturing plant, utilising the very latest technology, in Maidstone, Kent. The new facility will create an innovative power hub in Britain, not only serving the UK ventilation industry but allowing increased export to Europe and beyond.

In a celebratory event on Wednesday, esteemed representatives from the local Maidstone community, along with notable figures such as Faversham and Mid Kent MP, Minister of State (Department of Health and Social Care), Helen Whately, and The Worshipful the Deputy Mayor of Maidstone Cllr Martin Cox, gathered at the factory for the grand opening.

The distinguished guests were warmly received by Chairman of the Board of Directors for the 120-year-old Zehnder Group, Dr. Hans-Peter Zehnder and Zehnder UK Managing Director, Tony Twohig. Together, they performed the ribbon-cutting ceremony, and graciously welcomed customer representatives and attendees inside for an exclusive tour.

The new factory, located in the Hollingbourne area of Maidstone, has been strategically located to allow easy access to major transportation routes and infrastructure, providing an improved logistics hub and delivery capabilities for Zehnder customers throughout the UK. It features the very latest equipment and technology in ventilation manufacturing for Mechanical Ventilation with Heat Recovery (MVHR) units, trickle vents and single point extract fans – reducing the need for offshoring and allowing increased export into the EU.

Zehnder has made significant investment in the facility that will offer the increased production capacity, allowing the business to expand its product lines and services to meet the changing needs of its residential and commercial customers.

The new factory site has been designed to meet the highest standards of quality and sustainability and will incorporate the latest energy-efficient technologies to minimise its environmental impact. The new building operates at the highest energy efficiency through the implementation of solar panels, LED low energy lighting, which is light sensitive and self-adjusting, and heat recovery heating and cooling systems in the office areas.

Brand new machinery, such as plastic moulding machines, cooling systems and a fully electric vehicle fleet, including forklift trucks, also work to the latest energy efficiency ratings – lowering Zehnder’s carbon footprint and becoming a key part of its journey to carbon neutral.

The sustainability credentials of the new factory don’t end there. The new site is set up to recycle the energy from cooling water to heat or cool the machines, and then in the winter, reuse the heat from the compressed air system to warm the building – meaning the site is in a constant process of reuse and recycle, putting less strain on the local grid and surrounding amenities.

Zehnder has committed to staying in the Maidstone area. Most of the staff live within 12 miles of the site, including the factory’s operations manager, and every employee has access to a local free electric bus service to help them get to work. The launch will also open up job opportunities for local residents, with a focus on skilled and experienced professionals in the manufacturing and engineering fields.

The operations team will also use local businesses, such as packaging suppliers, facilities management companies, hospitality suppliers (for example local hotels and caterers), subcontractors (toolmakers, and materials suppliers) and logistics providers to help with external requirements.

Zehnder Commercial Director, Stuart Smith, said at the opening of the new facility: “It was an honour to welcome customers, staff and our esteemed local guests onto the new site today – and to have Hans-Peter Zehnder present to reinforce the importance of this opening for Zehnder Group made it an extra special occasion.


“Maidstone will offer us increased production capacity and more efficient technology to expand our product outputs and services across residential and commercial lines. This opening will really put Zehnder UK on the map as a centre of excellence for sustainability and energy efficient manufacturing practices as well as a global hub for exports across the world.

“Through our sustainability efforts and ongoing community focus, we hope to also make a positive impact on the area – creating job opportunities, supporting other local businesses and fully utilising the excellent logistic links that Kent offers.

“The technology we’ve brought into the factory production line is the very latest in cutting edge innovation for our market-leading ventilation systems and this investment is a testament to our commitment in providing our customers with the best products and services – as well as our dedication to sustainable manufacturing practices.”


Zehnder is known for providing high-quality ventilation systems, and the opening of the new factory in Maidstone, Kent, represents a momentous milestone in the company’s growth and expansion. The upgraded facility will enable Zehnder to continue to provide innovative solutions that meet the evolving needs of its customers, while also contributing to the economic growth of the region.


For more information on Zehnder and its products, please visit or contact us at

ElectricalDirect has added more products to its air purification range to help education specifiers and facilities managers protect indoor spaces against harmful germs and unpleasant odours.


Suitable for public and commercial spaces, ElectricalDirect has added the Vent-Axia PureAir Room Air Purifier to its range. This advanced multistage air cleaning system is able to remove 99.9% of airborne particles including COVID-19, viruses and bacteria.

The Vent-Axia PureAir Room Purifier also features a six-stage filtration system: a washable pre-filter, an H13 HEPA filter, an activated carbon filter, a cold catalyst filter, ultraviolet light, and an ionizer. With a capacity of up to 30m2 and a maximum noise level of 45d(B)A, the user will not be disturbed by loud background noise.

This portable and lightweight product also benefits from an auto mode that sets airflow based on the indoor air pollution, air quality display and a timer to allow you to set the unit to run for periods up to eight hours. Additionally, it features three speeds which can be manually or automatically controlled, meaning it can be easily adjusted for the level of usage required.

For increased functionality, ElectricalDirect also stocks the Vent Axia PureAir Room Air Purifier with Smart App Control which can be operated by its SmartLife app. This feature gives the ability to link multiple air purifiers to one app and remotely control each unit, speeding up the process of maintaining larger properties.

ElectricalDirect’s line up also includes the super slim air purifiers from AirX Pro, which is a medical grade air purifying system that removes 99.9% allergens and 93.3% of odours, from airborne viruses and dust mites to organic fumes, tobacco smoke, traffic pollution and more.

Carrie Earl, Category Manager at ElectricalDirect, said: “As part of our promise to offer a huge range of products, we are pleased to have increased our portfolio of air purifiers to meet the growing demand for improved air quality. These are excellent solutions to providing healthier indoor environments, especially as we approach winter and consider the health implications related to poor air quality.”

Specialist online retailer, ElectricalDirect has over 12,000 products in stock including everything from sockets, switches and cable management, to hand dryers and panel heaters. Education specifiers and facilities managers can choose from a range of flexible delivery options to meet the needs of their busy schedules, including free next day delivery on orders over £45 ex VAT, same day delivery to postcodes in selected areas of London and the East of England, as well as click and collect from 6,500 pick up points across the UK.


To find out more about ElectricalDirect, CLICK HERE


Inside the Saint Gobain Nottingham H.O.U.S.E, which optimises the use of solar energy, part of the Creative Energy Homes Project. Photography by Campbell Rowley

Keep your cool: Why building design is key to preventing houses from overheating

The UK has the oldest housing stock in Europe, due to the sheer volume of buildings constructed during the industrial revolution and post-wars when quantity was more important than quality. Consequently, most of our homes are cold in the winter months and vulnerable to overheating in the summer months.

Recent statistics indicated that 3.6 million living rooms in England had overheated during the summer of 2018 and, more recently, the UK experienced its hottest temperatures on record in July 2022 when the mercury rose to more than 40 degrees in Lincolnshire.

And now, the UK Health Security Agency has once again issued a heat-health alert for the week as temperatures are predicted to rise again, with some areas forecast to reach highs of 36 degrees by Saturday.

Lucelia Rodrigues, Professor of Sustainable and Resilient Cities at the University of Nottingham, discusses why building design is crucial when it comes to keeping homes cool.

She said: “Clever design means understanding and responding to context, including climate conditions. Most importantly, today’s designers need to make sure that buildings are climate resilient and are constructed with future weather scenarios in mind.

“Designing high-quality homes that are comfortable all year round does not cost any more than the construction of a ‘traditional’ home – it’s all about clever design as opposed to expensive technologies.”

In 2000, the university’s Department of Architecture and Built Environment launched Creative Energy Homes, an industry-funded project looking into innovative solutions that can make homes more comfortable and, crucially, carbon neutral.

Lucelia added: “The seven-house development has provided a living test-site for leading companies such as E.ON, David Wilson Homes, Saint Gobain, BASF and more, who have worked alongside us to investigate the integration of energy efficient strategies and technologies into houses.

“As part of this, we have implemented several strategies to help keep the buildings cool, from simple, low-tech solutions, such as shading, insulation, and effective natural ventilation, through to more sophisticated solutions, for example, phase-change-materials, earth-air heat exchangers and evaporative cooling.

“Understandably, it’s not possible for us all to simply redesign our homes. Therefore, we need to redesign the way we think, particularly as we prepare for another heatwave, to ensure both comfort and safety.

“While it might seem counterintuitive, closing windows during particularly high temperatures can, in fact, help keep the warm air out. Try to ventilate your home at night and in the very early morning instead when the air temperature is cooler. Additionally, stopping the sunshine from passing through the window can prevent the greenhouse effect, so it is important to shade the outside using shutters, brise soleils, or cleverly placed plants – even cardboard will do in particularly extreme weather. Finally, for any homeowners with an unshaded conservatory, open everything up, particularly high windows, to let the warm air escape.

“It is important to note that well-designed homes with highly-insulated envelopes that are comfortable and energy efficient in the winter months are also good at keeping the heat out in the summer, and technologies such as air-source heat pumps (ASHP) and mechanical ventilation and heat recovery systems (MVHR) can also aid cooling. If you are buying a new property or refurbishing yours do ensure you ask your supplier how you home will keep cool through the heatwaves that are sure to come.”

For more information about the Creative Energy Homes project, please visit:


By Andrew Cooper – Managing Director – Smartlouvre


It may be hard to believe that the ‘sustainability’ concept as it’s known today is less than 30 years old: it appeared for the first time in 1987.

Climate change (or global warming) conversely was first recognised as an issue more than 100 years ago. We can berate ourselves for the irresponsible damage we caused in the first 70 years, or we can focus on what we can do now.

The impact human activity has on the environment is now a big part of our children’s’ education, our day-to-day lives and is a global concern. In an overpopulated world where resources are exploited, the planet has no time to regenerate so we are finally changing our ways.

The construction industry was identified as one of the worst culprits many years ago, and the spotlight has been upon it ever since; house builders seem to be getting squeezed the most. Despite more than 2.2 million new residential buildings being built in England since 2010, we’re not yet achieving the 300,000 per year target, and some argue that we would actually need to build 340,000 each year to catch up with the current level of demand. Our overpopulation needs addressing fast with more new homes. The problem is that we’re constantly being bombarded with new building regulations, new rules and new guidance that we very quickly need to adopt in order to keep moving forward towards the (moving) targets.

The latest update to building regs, specifically focused on the residential sector is Approved Document O: Overheating. The goals of this new regulation are to stop us from cooking in our homes, to stop us simply cranking up the air-con as the planet heats up, and to stop us burning up energy with fans and air conditioning which draw us further away from net zero.

So, what does AD O say? Fundamentally, it restricts the areas of glass you’re allowed to have unless important criteria are met. Do we really have to live in the dark to be cool and kinder to the planet? Will we be facing the prospect of living in the dark like they did when the window tax was introduced in 1696? No, it’s not all doom and gloom (literally).

Shutters, external blinds, overhangs, awnings and of course, solar control glass are the suggested solutions, but they are in the most, designed to block natural, unfiltered daylight and in some cases, our vision out.

Under Document O shading also has to be ‘Fixed’ and ‘Passive’, so no moving or so-called dynamic systems are allowed. This is a no-brainer in terms of sustainability since dynamic systems need energy to or human intervention to operate and are therefore under a limited life cycle before maintenance or replacement is required. Furthermore, when they’re down they block your vision out and if it’s even vaguely windy they have to retract.

So, these fixed, passive shading options won’t damage the environment once in place, but we should still, as responsible constructors, consider the ‘cost’ of manufacturing them? What is the number one solution when it comes to keeping buildings cool, whilst limiting the impact on the environment? What we are comparing in terms of Approved Document O compliant shading products simply comes down to the materials they’re constructed from: metal, plastic, acrylic, vinyl or glass.

Metal is the stand-out winner, and of the metals, copper is the most sustainable and environmentally friendly. It’s also handily thermally conductive, so if we’re using it to protect us from the sun’s heat, it’s doing half the job for us.


CLICK HERE NOW to find out more


By Iain Fairnington – Technical Director, A.Proctor Group Ltd

This is an increasing question as to whether you require MVHR if your building is airtight. In a word, No, but it can be advantageous and to use a Technical phrase ‘it depends’!!

The levels of airtightness in UK construction regulations is constantly being lowered, arguably too slowly. Many people are now understanding that good levels of airtightness is a thermal improvement method, but are there knock on effects?
Iain Fairnington, Technical Director at the A. Proctor Group sits on BS 5250 committee which deals with Moisture Management and explained that the committee generally agree that the easiest way to avoid moisture build up is to put the heating up and open the windows. This allows any moisture to escape and avoids cold spots – Simple but not environmentally friendly. So, we need to look at how we manage the balance of Heat, Air and Moisture Movement.
When you have high levels of airtightness installation (low level airtightness) then this could lead to stale moist air being trapped inside a building, almost to “sweat” levels if the heating is not controlled. By introducing ventilation this moves the air out and replaces it with fresh air. Is this throwing out the baby with the bathwater when you have paid to heat that air and you are letting that warm air to escape while bringing in cooler air that needs heated up?

There are various ways to look at this including-

No ventilation system – here the airtightness is above 3 generally and only reliance is on trickle passive ventilation and mechanical ventilation in kitchens and bathrooms

MEV– Mechanical extract Ventilation- Here the ventilation system extracts moisture from areas such as kitchens, bathrooms, shower rooms etc., to the outside

MVHR– Mechanical Ventilation with Heat recovery- Here the air is extracted and any heat from this air is recovered

All have pros and cons and the ultimate decision will depend on a number of issues such as the need to filter air/reduce energy consumption or budget.
There is an old saying of “Build tight/ventilate right” which explains a lot in terms of the balance of getting this right. A self-build project may prefer to have an MVHR system and the owners be happy to change the filters every 6 moths or so, however a developer may not want to put this on the owner so may choose MEV. The MEV can be quieter and runs at a low pressure. The MEV can also be cheaper to install as not as much pipework is required.


Which ever system is chosen by the architect/developer or home owner, there is no need to be scared of airtightness levels being to low. There are solutions to ensure the building is healthy and efficient.

At the A Proctor Group we support the fabric first philosophy. We provide many solutions to build in energy efficiency and the moisture management. This can be seen in our Reflective membranes both external (Reflectashield TF) and internal (Reflectatherm) as well as our Wraptite which is an airtight vapour permeable externally applied self-adhered membrane for both walls and roofs. The Group supply high performance thin insulation systems for walls , floors and roofs which can also be used to reduce cold bridging in critical areas.

As with all decisions in life, it is all a balance of what’s important to you and others.

According to the Conservative Party manifesto the UK needs to build 300,000 new homes a year to deal with the ongoing housing crisis, an increase of over 50% compared to 2010 levels. 

Despite the desperate need for new homes, ramping up construction on this scale raises some obvious environmental concerns. Aside from land-use change, material waste and increased carbon emissions, increasingly there are concerns about the impact that the construction industry has on the quality of our air.   

According to the UK’s National Atmospheric Emissions Inventory, the construction industry has contributed to around 25% of the total nitrogen oxide (NOx) and particulate matter (PM2.5) pollution since 1970. 


The construction industry contributes to air pollution in several ways but one major source is the transportation of goods and services. Using traditional methods of construction it takes around two years to build a standard family home with an average of 22 different subcontractors needed. 

This, plus the delivery of goods and materials means that there can be upwards of 30 different vehicles visiting a construction site on any one day. When you multiply this by 300,000, it means a lot of moving vehicles, all producing air pollutants.  

One solution for reducing the number of vehicles travelling backwards and forwards from a site is constructing the properties off-site using Modern Methods of Construction.

MMC is a process which focuses on off-site construction techniques, such as mass production and factory assembly. MMC can be more sustainable as homes are precision-engineered to create less waste and are built using sustainable materials. This approach also provides benefits by speeding up delivery, reducing labour costs and improving quality. This means MMC can ‘kill two birds with one stone’ by helping us to ramp up our construction output  without contributing to environmental pollution. 

Andrew Shepherd, Managing Director of TopHat Solutions, a leader in the Modern Methods of Construction space explains: ‘Our manufacturing takes place in Derbyshire, and everything is built and created in one location as homes are mechanically moved around the factory. 

‘The houses then arrive at the site 95% complete, meaning the time spent at the construction site is a fraction of what normally happens. The contracting industry is extremely transient meaning people may live in one area but drive multiple hours a day to work in another. We have found that the people working in our factory are much more likely to live nearby and get public transport to work. This means we are contributing to much less transport emissions in the first stage of delivery.’  

Modular houses and Modern Methods of Construction have gained significant interest in the last few years with investment from the likes of Legal & General and Goldmans Sachs boosting confidence in the industry. 

The UK government has also begun to implement policy to shift towards modular housing, with schemes such as the Home Building and Construction Corridor  encouraging market growth and allowing the supply of these structures to be produced.  

However, currently only 15,000 modular homes are built per year, a fraction of the 300,000 needed.  


In areas where off-site construction is not possible, there are still ways that the industry can reduce its contribution to air pollution. According to one estimate, 14% of particulate matter (PM2.5) produced from the construction industry comes from the machinery used.  

James Bellinger, Senior Air Quality Consultant at global design and planning firm ARUP explains that this is because a lot of the tools and machines used at construction sites are powered by diesel generators.  

In a recent literature review, researchers at ARUP highlighted several key areas where developers can reduce air pollution. These include:  

  • Having a low or zero emission equipment requirement 
  • Planning for the on-site provision of grid electricity 
  • Planning sites so they can be built to allow for zero emissions
  • Considering emissions and equipment choices during the design of a project 

Despite clear ways to improve the air pollution output, James explains that the construction industry still has a big issue with communication.  

‘A key area for improvement is actually in the planning stages that are between where a site is designed and before a contractor is appointed to do the work.  

‘Historically, those two stages don’t work that well together and that results in opportunities being missed in the design process. For example, electrical connection could be added to avoid the need for diesel generators but because this communication doesn’t happen we are left with a situation where the contractor is appointed to do the work in a set amount of time and realistically they’re not going to turn up and ask for changes to reduce air pollution because for them, time is money.’ 

It is clear that to meet our housing needs we not only need to ramp up the scale of construction but we also need to shake up how we do things. However, as said by Andrew Shepherd, ‘There is a lot of muscle memory in the industry. 

‘There are lots of senior decision makers that have over 30 years worth of experience in doing things in a certain way, so asking them to do something completely differently is very difficult. To achieve our goals, we all need to invest and support future solutions.’  

A new British invention, following the co-location of Coltraco Ultrasonics’ Physicists and Scientists at Durham University, a globally outstanding centre of teaching and research excellence, the handheld Portascanner® AIRTIGHT 520 is a completely unique technology able to compute air flow and air permeability, quantifying leak sites to complement an airtightness test. Designed during COVID-19 with support from UK Government COVID-19 Emergency Technology Funding and available for exporting globally now, the Portascanner® AIRTIGHT 520 builds on Coltraco’s long history in watertight integrity monitoring for the Royal Navy to deliver the Safeship™ at sea, applying our advanced understanding of fluid dynamics at sea to air flow dynamics to deliver the Safesite™ on land.

The unique ability to detect, locate and quantify air leaks, non-disruptively and without the need for any room pressurisation, in a complementary manner to existing Door Fan and Pulse Airtightness Testing, will enable users of the Portascanner® AIRTIGHT 520 to make sharper decisions, verify technical specifications, and reveal possible defects if design standards have not been met rapidly and reliably.

The Importance of Building Ventilation: Changing Standards in the Built Environment
Professor Catherine Noakes OBE, who sits on the UK Scientific Advisory Group for Emergencies (SAGE) states that “if we do invest as a nation [in ventilation], there’s a potential big win,” with the “long-term payback [of] improved health and productivity, and lower energy use.”
COVID-19 is essentially an indoor air crisis. Whilst vaccinations are a crucially important tactical response, they must be complemented by longer term strategies. To ensure Human Air Hygiene, and safeguard that basic human right, a continuous and assured access to pure, fresh air, every public building must have a Ventilation Strategy.
In its most basic form, the challenge of building ventilation centres around increasing the number of air changes per hour. However, the integrity of air filtration, and or air purification, can only reasonably be assured if all unwanted air infiltration through gaps, is sealed. Air flow measurement devices, such as the Portascanner® AIRTIGHT 520, that allow for frequent and regular detection, location and quantification of unwanted air leaks must therefore be integrated alongside existing airtightness testing equipment, to ensure the success of building ventilation strategies.
In addition to Human Air Hygiene, Fire Suppression, Thermal Comfort, Acoustic Insulation, and Insect and Pest Control are all integral aspects of the Built Environment which require a certain level of airtightness to be maintained, either to deliver the minimum number of air changes per hour, restrict the supply of oxygen to extinguish a fire, or lower energy consumption and waste.
Indeed, in a post-COP26 global environment, addressing the effects of climate change and making buildings more energy efficient and environmentally responsible is driving the construction industry towards “Build Tight Ventilate Right.” Buildings are a significant producer of carbon emissions, accountable for 35% of total energy consumption.
Testing for air leaks and simultaneously testing for watertightness with the Portascanner® AIRTIGHT 520, as water ingress seriously damages buildings and destroys electrical equipment, will improve build qualities, and reduce the costs of operating and maintaining the Built Environment.

The Portascanner® AIRTIGHT 520: Unique Technology to complement Existing Airtightness Testing
During Coltraco Ultrasonics’ long history in watertight integrity monitoring for the Royal Navy they learned that it was one thing to be able to identify large and microscopic leak sites, but that it was quite another to precisely locate and quantify the leak site through the structure concerned to determine the water flow rate. These are the crucial pieces of information required to assess the damage control risk overall in a ship’s watertight compartment, watertight door or watertight Multiple Cable Transit Area between bulkheads.
The Portascanner® AIRTIGHT 520 takes Coltraco Ultrasonics’ understanding of fluid dynamics at sea and applies it to air flow dynamics on land. They take the best ultrasonic technology in Coltraco’s hardware to identify leak sites with a microscopic level of accuracy and apply computer science to measure and quantify the leak-site by the Portascanner® AIRTIGHT 520’s algorithm, which also generates a value for the air flow rate through that leak and the building’s overall air permeability.
The ability to record and analyse these 4 factors makes the Portascanner® AIRTIGHT 520, a British lightweight, hand-held, and portable analytical instrument, a unique technology globally. The Portascanner® AIRTIGHT 520 has been invented to complement existing airtightness testing, typically achieved using a Door Fan Test or a Pulse Test, that is essential for measuring the integrity of the Built Environment.

Integrate Dynamically with Essential Existing Technologies to be Better-Faster-Cheaper: Testing the Portascanner® AIRTIGHT 520 at The Airtightness Testing and Measurement Association’s (ATTMA’s) Building Performance Hub
In January 2022, Coltraco Ultrasonics’ Daniel Dobrowolski (Senior Physicist) and Bernard Hornung (Head of Built Environment) joined Paul Jennings (Airtightness Specialist) and Dr Bill Bordass OBE (Building Scientist) to test the Portascanner® AIRTIGHT 520 in a full-sized house. Testing followed a Pulse Test and a Door Fan Blower Test, both of which the Portascanner® AIRTIGHT 520 is designed to complement.

The Portascanner® AIRTIGHT 520 performed outstandingly, being able to identify and quantify leaks that had been found with traditional basic methods of leak detection such as thermal cameras, smoke pencils and anemometers, but most importantly finding leaks that could not be found with any alternative method. A significant number of leaks were identified in window and door seals.

The Portascanner® AIRTIGHT 520 allows the ultrasonic quantification of leak sites in a depressurised environment, which has never been achieved before. Door Fan Testing or Pulse Testing can then be conducted at an appropriate moment, once detected leakage points have been identified and repaired. Uniquely, during these tests, the Portascanner® AIRTIGHT 520 allows the location and measurement of air leaks, facilitating remedial action that is precise, immediate, and often low-cost.

Furthermore, Buildings can be surveyed with a Portascanner® AIRTIGHT 520 before an air tightness test so that they have a better chance of passing and, if a building fails an airtightness test, the diagnosis as to why it has failed could include locating and quantifying air leaks with the Portascanner®.

These capabilities of the Portascanner® AIRTIGHT 520 are even more important when one situates the device within the increased world-wide emphasis on airtightness in the built environment as a result of the dual pressures of COVID-19 and climate change. In the UK, higher standards on airtightness in the Built Environment are being encouraged by institutions such as the Passivhaus Trust, which forms a part of the global Passivhaus movement, and is the UK affiliate of the International Passive House Association.

Passivhaus builds are approximately ten times more airtight than the standard required of new-build domestic dwellings in the UK, meaning special attention must be paid to identify potential leakage areas in the building fabric and offsite-manufactured components during the final stages of construction. There are about 65,000 buildings worldwide which have achieved Passivhaus standards of comfort, health, and low energy consumption, with many more in the planning process.

Being able to use ultrasound to detect, locate, and quantify air leaks, eliminates the need for pressurisation, negative or positive. Therefore, the Portascanner® AIRTIGHT 520 can test building components when they are manufactured, such as windows and doors, which is where most leaks manifest themselves, with the aim to eliminate leaks before installation. During the execution of a build programme, or in the case of offsite construction, during the assembly of building components, building control aimed at assuring a better build quality should include the frequent and periodic use of the Portascanner® AIRTIGHT 520.

Coltraco Ultrasonics’ technologies provide their users with the unprecedented visibility necessary to make sharp decisions and understand opaque issues. Integrating the Portascanner® AIRTIGHT 520 with essential existing Door Fan and Pulse airtightness testing will improve build quality, and reduce the costs of operating and maintaining the Built Environment, by improving Human Air Hygiene, Fire Suppression, Acoustic Insultation, Thermal Comfort, and decreasing water ingress and absenteeism.

The availability of high quality modular buildings has been a huge advantage for hospitals and health trusts faced with urgent need for additional facilities, and increased pressure on funding.

Rapidly deployed modular buildings can offer a design life of up to 60 years but can be delivered in a fraction of the time taken for conventional build methods, making them an attractive option.
However, there is a concern that the drive to get the best value is often driven simply by the lowest price or fastest turnround, without taking into account vital requirements for patient care, in particular infection control and patient comfort

One area of primary concern is ensuring appropriate ventilation of modular buildings that is compliant with the highest standards and not simply meeting the minimum requirements within guidance documents.
Many buildings are supplied with no mechanical ventilation or air-handling system.  That may be considered adequate ventilation to meet those minimum standards, but adequate and appropriate are not the same thing.
Specific clean-air handling design for the internal configuration of each building should be a requirement to ensure appropriate air flow accommodating patients.
Ventilation is a crucial tool to protect patients and staff from the spread of potentially-harmful pathogens, and ensure their comfort and safety.

Infection prevention and control is vital in healthcare settings at any time, but that has been a primary focus during the recent COVID-19 pandemic.

Research into Coronavirus has indicated that the greatest danger of transmission is via aerosol-based routes and droplets carried in exhaled breath.  Ventilation and airflow is therefore increasingly important.
When specifying a modular building and choosing a supplier, hospitals and health trusts need to carefully evaluate the need for clean-air ventilation and its impact on a specific space configuration.  The underlying concept of factory-built accommodation is rapid production for a mass market at the cheapest price – not specifically designed and engineered modular building solutions for the medical sector.

Professor Cath Noakes from the School of Civil Engineering at the University of Leeds addressed the virtual Healthcare Estates Conference in October 2020 on the issue of ventilation.

Professor Noakes is leading research into ventilation, indoor air quality and infection control in the built environment.
She acknowledged that there is little data from real-world medical settings about COVID-19 transmission, but evidence from community settings shows the highest risk is probably within indoor environments and over short ranges.
In addition to droplets settling on surfaces, and the virus transmitting directly between people during physical contact; there is also evidence of airborne transmission of COVID-19, particularly in poorly-ventilated spaces.

People are at their most contagious when they are largely asymptomatic, so that it becomes increasingly important to consider ventilation of spaces housing patients.

She pointed out that airborne aerosol particles need drag force to keep them up and gravity to bring them down.  But air velocity in a room is known to impact on this and various-sized particles can remain in the air for a significant amount of time, often travelling quite far from their original source.

This is where clean-air ventilation can have a significant impact.

“If a space is well ventilated you can’t completely contain the virus, but the ventilation will dilute the virus and the risks are technically lower,” reasoned Professor Noakes.
This view is reflected in the Federation of European Heating, Ventilation and Air Conditioning Association’s recently-updated REHVA COVID-19 Guidance Document, which cites ventilation as the principal engineering control to help control infection, thus giving further weight to the vital role ventilation plays in the COVID-19 response effort.
It states that in hospitals with an optimal 12 air changes per hour (ACH) ventilation rate, aerosol transmission is mostly eliminated. But, in poorly-ventilated spaces, it may be dominant.
Professor Noakes suggests that in a hospital context it is not the obvious patient wards that will be most affected as these tend to be better ventilated.
Instead, estates and facilities managers and IPC teams need to also consider smaller, more-relaxed environments such as staff restrooms, waiting areas, corridors and treatment rooms.
“Hospitals need to consider where they are ventilating and what impact this has on a particular space,” Professor Noakes said.

However, mechanical ventilation is not provided in the standard specification of modular buildings.   Compliance with HTM 03-01 simply means that the supplier has met the minimum standards required. In addition, as with any natural ventilation method, the air flow and air change rates cannot be guaranteed as they are subject to external factors such as wind speed and direction.

The HTM 03-01 standard dates back to 2007, and therefore does not take into account the latest thinking on the need for clean-air design within the types of modular buildings increasingly used by hospitals for patient accommodation.
When it was produced in 2007 the use of modular buildings was very limited, but now they are seen as vital tool for increasing healthcare facilities.  An updated version of HTM 03-01 due for publication early in 2021 has received specialist input to address the latest thinking on clean-air requirements in patient accommodation.

Ventilation systems are complex solutions and their impact depends on the type of technology and, critically, how it is deployed.

The risks faced by healthcare workers treating patients with viruses that can be transmitted through the air are highlighted by research published in August 2020 by the Institution of Occupational Safety and Health (IOSH).

Researchers from University Hospitals of Leicester NHS Trust in the UK and Turku University of Applied Sciences in Finland examined these risks and how different forms of ventilation can protect staff who are treating patients in hospital isolation rooms, the study, called ‘Reducing aerosol infection risk in hospital patient care’, was commissioned by IOSH because while the risks to frontline healthcare workers when caring for patients with viruses are well known – less known is the optimal design of mechanical ventilation systems. The aim was to see how an engineering control approach of optimising ventilation methods can reduce these risks.

Dr Julian Tang, a consultant virologist at the University Hospitals of Leicester NHS Trust and an honorary associate professor at the University of Leicester, argues that: “The most-effective form of control is the ventilation engineering level of control.

“That means that we have to try and improve the amount of clean-air in the environment compared to the amount of contaminated air.

“The research has shown that there are certain types of ventilation – beyond just different speed and volume of ventilation – that can benefit healthcare workers better without being detrimental to the patient.
“And this report has tried to highlight those particular designs to show that if you are going to build a new hospital with new isolation rooms, these sorts of design are what you might want to follow.”
David Hartley, managing director at medical modular building specialist MTX welcomes the report: “The IOSH report focuses particularly on treating patients in isolation rooms, which are typically provided with a minimum of 10 air changes per hour of mechanical ventilation.  It underlines the importance of mechanical ventilation in reducing airborne aerosol infection.
“At MTX we recognise the importance of engineering air movement and clean-air flow pathways within modular buildings – particularly those housing patients.   Those factors are a vital consideration for our engineers when assessing the performance of the buildings we provide for health trusts and hospitals.  We have the technical expertise and experience to work with clinicians and facilities teams to ensure the building is fit for purpose in every case.
“Optimum airflow is accepted as an important factor in the health, wellbeing and comfort of patients and staff.  It is much more difficult and expensive to retrofit air handling systems to modular units, which is why it is so important to give it full consideration at the design and build stages.”

David Guilfoyle, a director at consulting M&E engineers DSSR which works with MTX adds:  “Ventilation has become much more of an issue with the emergence of COVID-19, and it has reshaped the priorities for ventilation requirements.  We work with MTX to ensure that the air handling provision is effective, bringing maximum benefit and enhancing the safety of patients and staff.”

DSSR designs central air handling for each modular unit produced by MTX according to how it will be used, the patient group and the internal configuration.

Mr Guilfoyle explains: “You have to walk in the shoes of the people who will be working in that building.  If you simply follow the basic HTM guidance you are not walking in their shoes. HTM is a baseline, not a target “Without talking to the clinicians and the infection control team you cannot possibly design an air handling system that is fit for purpose.  You must know the configuration of the beds and know how they are to be used.  Then you can design the system around the clinical requirements, not simply pump air into the room.  The configuration, positions of walls and corridors all influence the effectiveness of the air handling system.

“For example, people talk about 6 or 12 air changes per hour (ACH) ventilation rate in terms of volume, but that rate depends on the configuration.  Previously one of the priorities for air exchange was mitigating the effects of medical gases that could affect staff.  Now it is more about infection control – a priority that has gained momentum over the last year.
“Six ACH may be quite appropriate for one layout, but a different layout occupying the same floor space may require 12.  It is a bespoke solution every time with MTX, and clients get the benefit of flexible M&E design by experts in their field who understand the needs of staff and patients.

“We must also take into account air dilution rates – which reduce the particulate content of the air – a vital tool in reducing airborne infection of a virus like COVID-19.  In addition, clean-air pathways can be custom-designed according to the configuration of each individual modular building.

“If you want to capture the ‘bad air’ and vent it – then it all comes down to the pathways you create through the design of the system.”

Mr Hartley points out that factory-built units are too often simply mass-produced shells; they are not engineered for a specific purpose which may vary from one hospital site to the next.

“It is not one-size fits all.  For example, people who deliver a building in just a few short  weeks may be working hard to fulfil a need – but the building they produce may be a basic shell which could as easily be a schoolroom or an office.  Modular buildings used for patient care should be specifically designed and engineered for healthcare use.”

“Taking into account the threat from COVID-19 it is apparent that more attention needs to be paid to ensuring mechanical ventilation is considered in every case when designing and creating modular buildings.”

DSSR has been involved as a technical expert in updating the HTM 03-01 memorandum to make it more fit for purpose in modern healthcare. The new version is currently being ratified for publication early in 2021.