News Category: Product

With its extensive range of market-leading ventilation systems, products and accessories designed to work in harmony, Domus Ventilation is in the enviable position of providing customers with a single source for all their residential ventilation requirements.

Domus Ventilation manufactures high quality and solution-based ventilation products that save energy and improve indoor air quality from its state-of-the-art production facilities in South Wales.  It takes a whole house approach to ventilation, with mechanical extract appliances, ducting and accessories designed and third party tested for end-to-end system performance.  A ventilation system designed and installed entirely from Domus Ventilation components makes for a highly efficient one, with smooth air flow and minimum energy usage.

Established over 30 years’ ago, Domus Ventilation built its reputation for quality on its ducting systems in the early years.  Today, Domus rigid ducting is available in six different profiles, with high efficiency duct bends, supported by patented duct insulation, and sound attenuation components, for a complete duct system solution.  The company has expanded its product portfolio over the past decade to include mechanical ventilation systems such as the award winning HRXE range of Mechanical Ventilation with Heat Recovery (MVHR) systems; the highly energy-efficient CMX Mechanical Extract Ventilation (MEV) units; and a comprehensive range of intermittent extract fans. 

But the benefits of buying from a single manufacturer doesn’t stop just at the product range.  By using a single brand, you can benefit from the full range of support on offer.  In the case of Domus Ventilation, this includes technical support from a dedicated, in-house technical team offering a range of services from duct take-offs and estimations, to Revit MVHR and MEV system drawings, all completely free of charge.  The company also provides a detailed Specification Guide and offers several CIBSE CPD accredited courses.

Domus Ventilation, part of the Genuit Group, has a well-deserved reputation for quality, supported by excellent technical support, from a market leading manufacturer and designer.  The company provides differentiated ventilation solutions, transforming the way developers, contractors, installers, home owners and distributors meet Building Regulations Parts F & L and emerging environmental standards.

Following its success at 2022’s London Construction Awards, the Solis Air Brick™ from Domus Ventilation has added a further two accolades to its collection having recently won the Best External Product at the Housebuilder Product Awards and Innovation of the Year at the Wales Property Awards.

The Solis Air Brick may be a seemingly simple product, but its ability to provide a cost-effective means of compliance with the revised Building Regulations Fire Safety Approved Document B has made it an extremely popular one amongst customers, and award schemes!

Prior to the Building Regulations revisions, plastic was the standard material when it came to air bricks used as part of a domestic ventilation system.  With an increased emphasis on the fire integrity of buildings, Building Regulations Fire Safety Approved Document B was reviewed and changes made relating to the combustibility of materials used in external walls to reduce the risk of fire spread over the wall.  Now, ductwork penetrating through an external cavity, including termination, must be non-combustible when installed above 18m in England and 11m in Scotland. 

Made from 1.5mm galvanized steel (fire class A1) non-combustible material, the Solis Air Brick was one of the first to market that was able to meet these more stringent requirements, and ensure compliance. 

The Domus Ventilation Solis Air Brick comes in three sizes: 204×60 single metal air brick, and 220×90 and 220×126 double metal air bricks.  Bezelled versions, for use with exterior cladding instead of brickwork, have now also been added to the range.

Our Solis Air Bricks are suitable for use with all external wall types and are complimented by a wide range of stylish architectural grilles in a choice of colours.  They are fully compatible with Domus rigid ducting ranges and Domus Thermal duct insulation, a patented system that significantly improves the thermal insulation of round and rectangular ventilation ducting, thus reducing heat loss and preventing the formation of condensation.

The Solis Air Brick is the latest addition to Domus Ventilation’s Building Regulations compliant ducting fire protection products. The company offers a range of Fire Sleeves and Fire Collars that have been tested to BSEN 1366-3:2009 and classified to EN13501-2 which prevent the spread of fire where ventilation ducting penetrates fire compartment walls. 

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 Domus Ventilation, please contact vent.info@domusventilation.co.uk or visit domusventilation.co.uk

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.  Duct bend resistance is reduced by up to 60% with Domus ducting.

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-Zeus MVHR appliances, please contact vent.info@domusventilation.co.uk or visit www.domusventilation.co.uk

By Paul Williams, Domus Ventilation Product Manager

We may all talk about ‘the great outdoors’, but the truth of the matter is that we spend 90% of our time indoors.  For the majority of people, that time is mostly divided between home and our place of work / education.  The quality of our indoor environments – especially our homes which get the lion’s share of our time – therefore matter greatly for both our health and wellbeing. 

The impact of poor-quality housing is well documented, with the Building Research Establishment¹ (BRE) estimating the cost to the NHS in England being £1.4billion a year in treatment bills, primarily from exposure to cold and accidents.  But it’s not just defects in poor quality housing stock that are the problem.  We need to look at the bigger picture and how we approach housing design, which is something the Healthy Homes Bill has in its sights.

July 2022 saw the Second Reading of the Healthy Homes Bill in the House of Lords.  This Private Members Bill aims to transform the regulation of the built environment by making provision for the delivery of healthy homes and neighbourhoods that support the physical, mental and social wellbeing of residents.  The Bill addresses a very wide range of aspects that impact the health of a home, one of which is indoor and ambient air pollution.

Sources of air pollution

Sources of air pollution are varied. 

Externally, NOx (the collective name for Oxides of Nitrogen, with NO and NO² having the most effect on the environment and human health) and PM2.5 (particulate matter which is a mixture of solid particles and liquid droplets such as soot) are the main offenders.  The key emissions sources for these are transport and domestic fossil fuel burning respectively.  The UK government’s latest data shows that NO² limits are being exceeded in 33 out of 43 air quality assessment zones.  When it comes to PM2.5 levels, over 35% of local authorities (home to 22 million people) had unsafe levels in 2018.

Air pollution entering our homes is not the only issue to contend with when it comes to indoor air quality.  Building fabric, such as insulation, and countless building products emit potentially harmful pollutants into our homes, along with everyday activities such as cleaning and cooking.  Volatile organic compounds (VOCs) are some of the most common pollutants as they are found throughout building products. There is currently a distinct lack of standards for the control of indoor pollutants, although the recently revised Building Regulations ‘Ventilation: Approved Document F’ now includes guidance on indoor air pollution, including exposure limits and times for Carbon monoxide (CO), NO2, Formaldehyde (CH2O) and TVOC.

Impacts of Air Pollution

Air pollution can harm every organ in our body, can shorten our lives, and contribute towards chronic illness. Public Health England estimates 28,000 – 36,000 deaths a year can be attributed to long-term exposure to air pollution, making it the biggest environmental threat to health in our country. 

And it’s not just our health that suffers, but our wealth also; DEFRA estimates the economic cost from the impacts of air pollution in the UK at an incredible £9-19 billion every year.

Designing out Air Pollution

Whilst we can’t prevent people from using potentially harmful cleaning products at home, or frying meat (another source of indoor air pollution), there are measures we can take to extract these pollutants, to reduce external air pollutants entering the home, and to limit the pollutant emissions from the building fabric.

As laid out in the Healthy Homes Bill: “all new homes… must be built to minimise, and where possible eliminate, the harmful impacts of air pollution on human health and the environment”.  In order to achieve this, good ventilation is essential to disperse pollutants. 

Under Building Regulations, natural ventilation systems, such as background vents, are permitted although only for less airtight homes with a design air permeability of ≥ 5.  However, natural ventilation isn’t an efficient means of ventilating a home as heat will be lost and there is no guarantee of moisture or pollutants migrating outside.  As recognised in Building Regulations, good ventilation is best achieved through mechanical ventilation systems, with the most effective being Mechanical Ventilation with Heat Recovery (MVHR).  These bring fresh air into the home and extract stale air, along with the pollutants. 

Mechanical ventilation systems not only address air quality in terms of removing pollutants, but they are also highly effective at preventing condensation and subsequent mould formation; dealing with overheating in the more air tight new homes we now build; and even in reducing air born virus transmission.  So even if we meet all our goals and bring external air pollution down to WHO acceptable guidelines, mechanical ventilation remains an important aspect of a healthy home.

When it comes to reducing external air pollutants entering the home, Building Regulations provides advice on the location of intake grilles, primarily away from the direct impact of the sources of local pollution. Where urban traffic is a source of pollution, the air intakes for dwellings next to busy urban roads should be as high as possible and located on the less polluted side of the building.  Ventilation intakes should not be located in courtyards or enclosed urban spaces where air pollutants are discharged.

However, in areas of high pollution, this may not be enough. In these circumstances, the MVHR system may actually be bringing polluted air into the home.  Although they come equipped with standard filters, these can only do so much.  Installing a powerful Carbon filter to the MVHR system would be an effective approach.  The Domus Ventilation’s NOX-FILT, for example, which works on the supply leg of the ducting, prevents up to 99.5% of NO² pollution from entering a home. 

Limiting potentially harmful emissions from the building fabric requires the use of ‘healthier’ building materials and products.  As the Healthy Homes Bill states: “all new homes should not contribute to unsafe or illegal levels of indoor or ambient air pollution”.  What constitutes healthier, safer building materials is for another article though.

Domus Ventilation is a manufacturer of market-leading ventilation systems that save energy and improve indoor air quality.

www.domusventilation.co.uk

vent.info@domusventilation.co.uk

¹ ‘The Cost of Poor Housing in England’, BRE

Prior to a revision of Building Regulations in 2010, ventilation was not high on the list of priorities in the house building sector.  A fan in the bathroom and cooker hood in the kitchen, plus ventilation blocks in the walls, were the default setting.  Then, gradually, ventilation began to make it on to the agenda, largely driven by the now defunct Code for Sustainable Homes. 

The Code required homes to be better insulated and more air tight to stop the heat leaking out of them and wasting energy.  Of course, the more air tight a property is made, the greater the requirement for ventilation to ensure good quality indoor air.  At the time the Code was in use, the focus was on preventing / removing condensation.  More recently fears over pollution and over-heating have taken over as the imminent threat to the health of residents. 

Changes to Building Regulations Part F announced this year acknowledges these issues and the important role ventilation has to play in maintaining good indoor air quality.  It lays out more stringent ventilation requirements for new builds, plus proof of effectiveness, so ventilation can no longer be ignored or side-lined.

To ensure adequate, Building Regulations compliant, ventilation in a property and for it to be signed off by Building Control, then a mechanical ventilation system, such as a Mechanical Extract Ventilation (MEV) or Mechanical Ventilation with Heat Recovery (MVHR), is required. 

One of the key issues identified when reviewing existing Building Regulations has been the fact that a large number of homes – including those using mechanical ventilation – are not compliant with Part F (ventilation).  Why is this?  Is it deliberate; cutting corners to save money?  Or is it a lack of understanding of how mechanical ventilation systems work and how a whole system approach is required?

In our experience – which is considerable – it is a mixture of both.  All too frequently key elements of a mechanical ventilation system are skimped on to save time and money and also because they are seen as unnecessary.  Here we identify the five most frequent corners cut and why they matter, plus some tips for where you genuinely can make savings.

System Design

Designing a whole house mechanical ventilation system, especially an MVHR, requires a level of skill.  Whilst the location of the air handling unit is normally straightforward, the duct runs, the number of bends and the angle of those bends, plus the temperature of the areas the ducting runs through, all affect the air flow.  The air flow needs to be maintained at a set level if the system is to perform to its best ability.

To avoid the cost of employing the services of a qualified system designer, we have frequently seen builders and contractors taking an ‘educated guess’ at where to locate the ducting.  This rarely ends well, especially when it’s done more as an after-thought, when options for duct runs have become limited.

However, there’s actually no need to cut costs here as most manufacturers will provide a system drawing free of charge, along with duct take-offs and estimations.  The good manufacturers will provide on-going support so if you do run into any unforeseen difficulty you can call upon them to help you out of the problem.  They want the system to work and they want your repeat business, so be sure to use their free support.

The Ventilation Unit

The most obvious place to try and reduce costs is to buy a cheaper MVHR/MEV unit.  It’s true, you don’t always need the ‘Rolls Royce’ model, but going for the lowest cost option could actually cost you more in the long run.  That’s because, when it comes to a whole house mechanical ventilation system, a large amount of the cost is in the labour.  Better quality units may come at a higher price, but they are often designed with ease of installation in mind. 

Look out for units that are compact and lightweight so can be handled by a single person (as well as giving you more options on where to install them); that are available as opposite handed models to allow for installation horizontally or vertically; and that have their controls accessible via a front panel for easy commissioning.  Also check to see if the unit’s spigots can be directly connected to the most common ducting size, rather than requiring adaptors and flexible hose to connect to flat channel ducting, which will end up adding to the bill.

Ducting

Sadly, ducting is the number one sauce of problems when it comes to mechanical ventilation systems as this is where most of the costs are cut. 

Poor quality ducting that doesn’t have exacting tolerances (i.e. where the channel or pipe bows, or looks like it is concave, or the wall thickness appears uneven), will not push fit together, so end up taking more time to install.  More importantly, they result in air loss which reduces the system efficiency and increases the risk of moisture leakage around the connections which can lead to ugly stains.  If you want your mechanical ventilation system to function correctly, it’s imperative to invest in quality ducting that has been designed to work in harmony as part of a system and has been third party tested for end-to-end system performance. 

A quality ducting system will also usually come with a range of accessories which allows for a variety of solutions to unforeseen site circumstances.  Many of these are of a more specialist nature, such as ducting silencers and aerodynamic bends engineered to reduce system resistance. 

Insulation

Ducting insulation is required under Building Regulations where the ducting passes through unheated areas and voids, such as loft spaces.  The minimum duct insulation standard is the equivalent of at least 25mm of a material having a thermal conductivity of ≤0.04W/(m.K). 

Specialist duct insulation, such as Domus Thermal, is essential to meet this requirement.  A common mistake that is made is using insufficient insulation, using standard building insulation materials that are unsuitable or not using any insulation at all.

The problem with poor insulation is that condensation forms, which can lead to mould which is not only unsightly but can be hazardous to health. 

Fire Safety

When a hole is made in a compartment wall for plastic ventilation ducting to pass through, the hole must be fire-stopped to restore the walls’ fire rating in accordance with Approved Document B of Building Regulations.  It is essential that the firestopping product used for this has been specifically designed for this purpose. 

As with insulation, we have seen inappropriate material used and have also witnessed fire sleeves for ducting removed from systems altogether to save costs.  Clearly, the results of this action could have considerably worst consequences than mouldy walls.  With the recent climate of improved fire safety awareness, this has become less of an issue.

In 2021, the UK was found guilty by the European Court of Justice of “systematically and persistently” breaching air pollution limits. The court ruled that, since 2010, the UK had failed to tackle the problem of toxic NO² emissions in the shortest possible time.  The UK government’s latest data shows that NO² limits are being exceeded in 33 out of 43 air quality assessment zones. 

Measures to tackle air pollution have been announced, which cover both NOx (the collective name for Oxides of Nitrogen, with NO and NO² having the most effect on the environment and human health) and PM2.5 (particulate matter which is a mixture of solid particles and liquid droplets such as soot).  It aims to have new legal air pollution limits in place by October 2022, which will be informed by WHO guidelines.

So, air pollution is being taken seriously, but the focus is on external air pollution. When you consider we spend 80-90% of our time indoors, are we in danger of side-lining indoor air pollution? 

What are the indoor pollutants?

When it comes to outdoor air pollutants the focus is very much on NO² and PM2.5, with the key emissions sources being transport and domestic fossil fuel burning respectively.  For those living near busy roads and in built up areas, these emissions remain a problem indoors as well as outdoors as they readily enter homes around closed doors, through windows etc.

But pollution is also generated by activities conducted within the house.  Levels of particulate matter (PM) increase burning fossil fuel such as gas cookers and heaters, and even candles.  The cleaning equipment used often contains harmful toxins that accumulate indoors and linger. Even seemingly innocuous items within homes, such as furniture and the very materials these homes are built from, can release potentially harmful pollutants if properties are poorly heated and ventilated.

Sadly, this is a much under studied area and our knowledge of the sources and worst effects of indoor air pollution is lacking.

How to address indoor pollutants

Whilst ‘there are things that we know we don’t know’, as the saying goes, the things we do know that cause potentially harmful pollutants indoors we can address.

The first and easiest one of these is to switch to non-toxic cleaning products.  The second is to move away from fossil fuels in our home.  Whilst these focus on removing the pollutant at source, the third way to address pollutants in our homes is to disperse them through effective ventilation.

The simplest form of ventilation is to open windows, but this isn’t a good option if the property is in a heavily polluted area as you are simply bringing more polluted air into it.  Basic mechanical ventilation, such as bathroom and kitchen fans are essential and will remove a level of pollution (as long as they are correctly ducted!), but to truly make a difference you need to turn to mechanical ventilation systems.  And this is where housebuilders can make a potentially life changing difference to future home owners and residents.

Effective ventilation = mechanical ventilation

Mechanical ventilation, in the form of intermittent extract, continuous extract or supply & extract, are recognised as the most proficient means of ventilating a modern property. 

Mechanical Extract Ventilation (MEV) and Mechanical Ventilation with Heat Recovery (MVHR) systems actively extract air from wet rooms (kitchens, bathrooms, utility spaces) via ducting to a central ventilation unit which exhausts to the atmosphere.  In the case of MVHR, there’s the added benefit of supply and extract ventilation combined as these systems re-use waste heat from the extract air and use it to efficiently pre-warm the fresh air drawn into the building using a heat exchanger.  The filtered, pre-warmed air is then distributed around the home, effectively meeting part of the heating load in energy efficient dwellings.  Domus Ventilation’s new HRXE-HERA® and HRXE-AURA® MVHR units feature advanced heat exchange proficiency enabling up to 95% of waste heat to be recovered.  They come with 100% thermal (summer) 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. 

Both MEV and MVHR systems provide effective ventilation, are energy efficient and extremely effective at dispersing polluted air. 

Even with these clever systems, they still rely on brining outdoor air in so, in more polluted areas such as cities – you will need to combine them with a filter.  The Domus Ventilation NOX-FILT, for example, works on the supply leg of the ducting system of a mechanical ventilation system and prevents up to 99.5% of NO² pollution from entering a home.  There are two units in the range with the second one having the added benefit of a PM2.5 pre-filter. 

Because of the nature of these systems, which require extensive ducting, they are mostly suited to new build properties.  For existing properties, the most cost-effective options are bathroom and kitchen intermittent extraction fans (Axial and Centrifugal) and Positive Input Ventilation units (PIV).  PIV units are a cost-effective method of eliminating moisture from the home by gently pressurising a dwelling to expel stale and humid air through natural ventilation points.  They can be mounted either in the loft area of a house, or a hallway cupboard of a flat.

Getting to grips with indoor air quality

We certainly don’t want to detract from the work being done to improve external air quality – it’s literally life saving – but we do need to start taking indoor air quality seriously.  We should feel safe in our homes. 

This year, Domus Ventilation is pleased to announce it is exhibiting at even more Specifi Mechanical Services events than ever before.  Three shows – in Bristol, Manchester and Birmingham – have already been held and a further five are booked for the remaining year, in London, Edinburgh, Dublin and Leeds.

Aimed at the full gamut of specifiers in the construction sector, the Specifi events provide a more relaxed, informal alternative to major exhibitions.  They are designed for networking and professional development through the sharing of information. 

Aimed at the full gamut of specifiers in the construction sector, the Specifi events provide a more relaxed, informal alternative to major exhibitions.  They are designed for networking and professional development through the sharing of information.

Domus Ventilation’s experienced Specification Sales Manager, Russell Beardsworth, will be attending all the Specifi shows booked by the company.  He will be advising visitors on the latest, cost-effective ventilation solutions available for residential and light commercial applications.  Russell will also be highlighting Domus Ventilation’s new and updated RIBA and CIBSE CPD accredited courses on residential ventilation, which have proven very popular amongst specifiers.

Domus Ventilation takes a whole house approach to ventilation, with mechanical extract appliances, ducting and accessories designed and tested to work in harmony and achieve the highest possible efficiency.  The company strives to deliver ever more efficient products and systems, including the latest MVHR systems: HRXE-HERA™ and HRXE-AURA™.  These units feature advanced heat exchange proficiency enabling up to 95% of waste heat to be recovered.  They come with 100% thermal (summer) 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. 

Designed to work on the supply leg of a ducting system of a mechanical ventilation system, Domus Ventilation’s NOX-FILT, will also be discussed.  This innovative filter prevents up to 99.5% of NO² pollution from entering a home.  A second unit in the range has the added benefit of a PM2.5 pre-filter.  With air pollution now a major issue, the NOX-FILT provides residents with added protection.

Further Domus Ventilation products to be highlighted at Specifi, will be the CMX-MULTI Mechanical Extract Ventilation (MEV) unit; a selection of extract fans, including the recently released D-dMEV single flow, continuous running decentralised mechanical ventilation fan; ducting and ducting insulation; and products that enable compliance with Building Regulations Fire Safety Approved Document B, such as the new Solis air brick.

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 more information on the location and times of Specifi events, plus to register for free attendance, go to www.specifi.co.uk.  For more information on Domus Ventilation, go to www.domusventilation.co.uk.

Domus Ventilation, part of the Polypipe group, has launched the new Solis Air Brick™ range of low resistance, non-combustible metal air bricks that are fully compliant with the revised Building Regulations Fire Safety Approved Document B.

Changes to the Building Regulations, which came into force in November 2020, requires “Ductwork penetrating through the external cavity including termination to be non-combustible” when above 18m in England and 11m in Scotland, although it is expected the more stringent 11m rule will eventually be applied throughout the UK.  The new Solis Air Brick is made from 1.5mm galvanized steel (fire class A1) non-combustible material to meet these changes to the regulations and ensure compliance.

The Domus Ventilation Solis Air Brick comes in three options: 204×60 single metal air brick, and 220×90 and 220×126 double metal air bricks.  They are suitable for use with all external wall types and come with a wide range of stylish architectural grilles in a choice of colours for internal and external use.  They are fully compatible with Domus rigid ducting ranges and Domus Thermal duct insulation, a patented system that significantly improves the thermal insulation of round and rectangular ventilation ducting, thus reducing heat loss and preventing the formation of condensation.

The Solis Air Brick is the latest addition to Domus Ventilation’s Building Regulations compliant ducting fire protection products. The company has a range of Fire Sleeves and Fire Collars which prevent the spread of fire where ventilation ducting penetrates fire compartment walls. 

For customers wishing to find out more about the recent changes to Building Regulations, a Domus Ventilation Continuing Professional Development (CPD) accredited course on “Residential Ventilation Principles and Building Regulations” has recently been launched.  The course covers changes to Building Regulations Part B – Fire Safety in relation to mechanical ventilation, as well as addressing recent changes to Part F – Ventilation.  The CPD course, which runs between 45-60 minutes, can be booked through megan.bennett@domusventilation.co.uk.

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, please contact vent.info@domusventilation.co.uk or visit www.domusventilation.co.uk.

Mechanical ventilation is a growth sector and one that has partly come about based on the unintended consequences of making our new build homes more energy efficient.  In part driven by the now defunct Code for Sustainable Homes and by more demanding Building Regulations, new housing is fitted with high performance insulation and heat loss has been minimised.  This is positive news when it comes to sustainability, but less so when it comes to occupier comfort, especially in the summer months when over heating becomes an issue.  A study for UK Green Building Council – ‘Healthy housebuilding: Making 300,000 new homes a year better places to live’ – shows satisfaction with summer comfort levels in new homes is at just 76%, compared to 89% for older homes.  The study states ‘Careful configuration of windows (with shading if necessary) and suitable ventilation strategies will be necessary to raise wellbeing standards throughout the year.’

In order to achieve the correct level of ventilation, whole house, mechanically driven systems such as Mechanical Extract Ventilation (MEV) and Mechanical Ventilation with Heat Recovery (MVHR) are required.

Traditionally, mechanical ventilation installation has been undertaken by specialist contractors.  That’s because whole house ventilation and heat recovery systems require not only an understanding of the technology but also a good level of competence from the installer in all aspects of the system, including ducting.  Sadly, poor quality ventilation installations abound; so bad is the situation that Standard Assessment Procedure (SAP) actually deducts points against a building’s ventilation ducting as it assumes it will be of a poor quality!  SAP calculations are used to measure the energy efficiency of dwellings and are required for all UK new build developments.

Bearing this in mind, just how difficult is it to break into this sector and is it worth the effort?

Domus Ventilation is a manufacturer of ventilation systems and we run our own BPEC accredited ventilation installer training course, so we’re biased!  We’re passionate about all things ventilation and our answer is therefore obvious.  So, rather than listen to us, we think it would be far more useful for you to hear from someone who has recently branched out into ventilation from the plumbing sector.  Matthew Broad, co-owner of H2O Building Services Ltd. based in South Wales, spills the beans.

Established for over ten years, albeit in different forms, H2O initially purely provided plumbing and pipefitting services.  Over recent years, the company has grown and expanded its services to include sprinkler design, installation, signoff and maintenance and full mechanical packages in both residential and commercial sectors, primarily in South Wales, but also further afield.  The majority of these are undertaken in-house, but a reliable sub-contract team of between 12 – 20 operatives are on hand to complete specialist works (under floor heating, air conditioning, BMS controls, insulation, chlorination, servicing and commissioning) under H2O’s supervision.  

The latest addition to H2O’s in-house services is mechanical ventilation.  The company was sub contracting this, but saw it as a potentially profitable service to bring in house and also meant they could retain greater control of the overall work being conducted under their name.

H2O has not found the move into ventilation too challenging, as a number of skills are transferable, as Matthew explains: “there are a lot of similarities between ventilation and plumbing, so this helps us a lot when installing.  Our guys are used to running between four to eight different pipework systems in, so to run a couple of 204 x 60mm plastic ducts in to an MEV system came relatively easy to our operatives, with the help and guidance of a few people along the way. 

“However, MVHR was a bit more difficult and demanding. The most challenging aspects of MVHR was familiarising ourselves with the different types of duct fittings available and also the concept of the system itself and how to install the first fix well enough to make the second fix (on show) look the best it can.  Getting the bracketry correct is key to the installation looking its best.  The more and more we are fitting the MVHR systems, the more confident we are getting with it; practice makes perfect!”

H2O has received excellent support from VME Distributors Ltd. in Cwmbran, Gwent.  “The importance of VME, John Dunleavy in particular, is paramount and critical to how H2O have progressed as a company on the ventilation side of things” states Matthew.  “They are always on hand for advice and guidance which is key to us gaining confidence and making sure things are done correctly.  John is also a critical part of advice/guidance on Building Regs etc.”. H20 is fitting Domus Ventilation units including, most recently, HRXD MVHRs into The Moorwell apartment block in Penarth. 

VME’s John Dunleavy believes sourcing the right supply chain is essential to the success of installers and contractors entering the ventilation sector.  “The residential sector is a growing ventilation market and we are seeing more contractors taking on ventilation as a package.  Fitting ducting is a straightforward task for them, as is basic intermittent ventilation, but continuous ventilation is more complex.  They often feel out of their comfort zone and they lack confidence.  This is where linking up with a good manufacturer and a ventilation distributor is important, as these will supply the support and advice they need and give them access to BPEC courses for installation competency.  After all, if they get it wrong and Building Control picks up on it, they may well be liable for correcting any mistakes they have made.”

John offers some further useful advice for newcomers: “Ventilation should never be an after-thought, so don’t leave decision making to the last minute.  Don’t just accept a specification as it stands.  I often see wholly inadequate ventilation specs that will not pass Building Control, so it’s important you understand the different types of system and what they will achieve; training is therefore important.  And don’t think ‘cheap’.”

So ultimately, is it worth it?  Whilst Matthew and his team haven’t found it too difficult to learn the basic installation skills, he thinks the housing sector still has a way to go: “I think the industry, especially housing, still needs convincing of the benefits of these ventilation systems.  However, we are doing a lot of flats at the moment and definitely seeing an increase in it.  I think it is the future though and will become more and more popular”.

For H2O, getting in at this stage of the game is a strategic move that it thinks will pay well in the future.  The learning curve has not been overly steep and many of its operatives’ skills are readily transferable.  Opportunity has knocked for H2O and it has opened the door!

Ventilation has become a key concern in our buildings.  Ventilation has progressed from the primary concerns around condensation and mould prevention; to reducing over heating in the more air tight new homes we began to build in response to the Code for Sustainable Homes; through to addressing the issue of harmful indoor air pollution.  Most recently, ventilation is being talked about in the light of reducing virus transmission, elevating the subject to something that the everyday person now discusses and is aware of.

Ventilation and Coronavirus

Coronavirus, which causes the COVID-19 disease, is primarily spread in indoor environments by people breathing in infected droplets and smaller ‘aerosol’ particles in the air that have been exhaled from the nose and mouth of an infected person. 

Whilst masks help to limit the spread of these droplets, good ventilation is essential to disperse them.  Without ventilation, which brings fresh air into a building, the particles are unable to disperse, lingering in the air for hours and building up over time.  The more people that are in an unventilated area, and the longer they spend in that space, the more likely they are to breath in these particles and become infected with the virus.

A short film released by the Department of Health and Social Care in November 2020, which is part of the ‘Hands. Face. Space’ campaign urging the public to adopt simple health behaviours to help reduce the risk of the virus spreading, shows how ventilation can reduce the risk of infection from Coronavirus by over 70%, as fresh air dilutes the particles.  The video focuses on natural ventilation through opening windows, but also acknowledges the role mechanical ventilation systems have to play when used correctly and regularly. 

An advisor on the film and part of the government’s Scientific Advisory Group for Emergencies (SAGE), Professor Catherine Noakes studies air movement and the infection risk associated with different ventilation systems. Her research highlights the importance of good ventilation as a way to stop the spread of infection in indoor environments. “When a room does not have any fresh air,” she states “…that is when transmission of coronavirus is most likely. Fresh air must come from outdoors – recirculating air just means the aerosols containing the virus move around the same room rather than being extracted outdoors.

“Ventilation units or any household systems that use outdoor air can be just as effective as opening windows or doors as long as they are limiting the recirculation of the same air.”

The Benefits of Mechanical Ventilation in Reducing Transmission

Whilst extract fans in bathrooms and kitchens provide a basic level of ventilation and are low in cost, they are only one step above opening a window.  Using these fans, replacement fresh air is provided via background ventilators and normal air leakage.

For a more effective solution, that ensures fresh air reaches all rooms in a home and pollutants are directly extracted without losing costly heat from the property, whole house mechanical ventilation solutions can’t be beaten, especially if you opt for a Mechanical Ventilation with Heat Recovery (MVHR) system.

MVHR combine supply and extract ventilation in one system.  They work on the principle of extracting and re-using waste heat from ‘wet rooms’ (kitchens, bathrooms, utility spaces).  They efficiently pre-warm the fresh air drawn into the building with waste stale air using a heat exchanger.  The filtered, pre-warmed air is then distributed around the home, effectively meeting part of the heating load in energy efficient dwellings.  Domus Ventilation’s new HRXE-HERA™ and HRXE-AURA™ MVHR units feature advanced heat exchange proficiency enabling up to 95% of waste heat to be recovered.  They come with 100% thermal (summer) 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. 

MVHR systems provide effective ventilation, are energy efficient, extremely effective at reducing the risk of virus transmission, condensation and cold air draughts and, with their built-in air filters, are particularly useful in more polluted urban areas. 

A lower cost, easier to install alternative to MVHR, Mechanical Extract Ventilation (MEV) systems are also available.  These actively extract air from wet rooms via ducting to a central ventilation unit which exhausts to the atmosphere.  The systems are typically two speed, providing low speed continuous trickle ventilation and high-speed boost flow.  Replacement fresh air is drawn into the property via background ventilators located in the habitable rooms and through air leakage. 

Both types of system have been recognised by the World Health Organisation (WHO) as providing a line of defence against the spread of coronavirus. 

Because of the nature of these systems, which require extensive ducting, they are mostly suited to new build properties.  For housebuilders, these mechanical ventilation systems are no longer being seen as ‘nice to have’, but are slowly transitioning to something more akin to life safety systems. 

Lest we Forget: Air Pollution

Ventilation in our homes has never been more important, but it would be a mistake to focus solely on coronavirus as the only threat to our health. We have been in the midst of a health crisis for some time, caused by pollution in the air we breathe.  According to NHS England, 30% of preventable deaths in England are due to non-communicable diseases specifically attributed to air pollution.  Particulate matter, notably PM2.5 and NOx, are the biggest threats here.  This has been sadly brought to the fore by the recent recognition of air pollution as a cause of a person’s death for the very first time in the UK, and possibly the world.

However, much of the focus on air pollution has been on polluted external air, whereas our exposure to air pollution mostly happens indoors, where we typically spend 90% of our time; with coronavirus lockdown periods, this figure has increased, along with the risk to our health. 

Indoor air pollution sources are widespread and vary dramatically from house to house.  Sources include cooking, cleaning, fires, candles and even building and decorating materials.  Outdoor air pollution is another source and features some of the more lethal types of pollution including nitrogen oxides, which are tiny particles that can easily enter our homes around closed doors.

For reducing indoor air pollutants, experts agree that both source removal and ventilation are key.

We have already looked at how whole house mechanical ventilation systems work and how effective they are in distributing fresh air throughout the home.  But in more polluted areas, such as cities, bringing air into the home also brings in dangerous pollutants, especially if the property is located near a busy road.  In these instances, ventilation has to be combined with filtration.  The Domus Ventilation NOX-FILT, for example, works on the supply leg of the ducting system of a mechanical ventilation system and prevents up to 99.5% of NO² pollution from entering a home.  There are two units in the range with the second one having the added benefit of a PM2.5 pre-filter. 

Whilst the unexpectedly hot spring and summer months of 2020 saw external air pollution drop dramatically as we lived through the first coronavirus lockdown, sadly this has not been repeated in the second nationwide lockdown this winter.  With even more time spent indoors out of the bad weather, not only have we sadly seen a rise in COVID-19 infections, but also air pollution.  This has come from the large numbers of people working from home, who are using their gas boilers – a major source of local pollution – during the day, when normally they would be in their workplace and the heating at home would be off.  At the same time, many workplaces will continue to be heated for those staff who are in.  NOx emissions from cars are unlikely to drop much as, although fewer people are going to the workplace, many are using cars when previously they would have taken public transport.

The Years Ahead

No one is pretending that 2021 is going to be a good year, but there is light on the horizon for sure.  We are witnessing one of the biggest vaccination programmes in the history of the world in a bid to fight coronavirus.  We are also seeing governments across the world taking air pollution seriously and putting measures in place to reduce it.  And we are seeing ventilation being recognised as a valuable and relatively low cost means of improving our indoor environment and our health.