Overlooked legislation changes causing problems for AHU filtration


14 April 2022
Offices and workrooms are covered by new Building Regulations as ‘occupiable rooms’ where air quality must now be monitored. Copyright: DigitalGenetics. Credit: Adobe Stock / S&P UK Ventilation Systems

Lee Page, sales director at S&P UK, raises concerns that recent changes to legislation and recommendations may not filter through to some people and risks causes air handling units (AHUs) being wrongly selected or inadequately installed for building projects.
We admit it – staying up to date and reacting to key legislation changes and recommendations that encircle the HVAC industry are probably not the most exciting part of our day-to-day working lives. But they are unavoidably essential – especially if you care about indoor air quality (IAQ) and delivering the very best for your customers and end users.

Air purification is undergoing a renaissance in society due to the pandemic and the repeated high-profile soundbites and public health messaging over ‘ventilation’ – ventilation in the workplace, in schools, in public buildings like restaurants, museums and shops.

Filtration is a subject that everyone in HVAC is talking about under the banner of IAQ and yet from our perspective as a leading ventilation manufacturer, new recommendations from Building Regulations and EN standards, and their consequences for specifications, aren’t filtering through to the right people as much as one would hope or expect.

Whether that’s due to a lack of investment in training or internal communications, or just general disinterest, it’s a serious problem that needs addressing because it could lead to products such as AHUs and heat recovery units being specified and used without the most up-to-date recommendations and legislation for filtration.

It’s a problem that may be impossible be rectify later down the line by simply installing higher grade filtration because of potential motor power problems and current specific fan power requirements.

So with such a powerful role to play for us HVAC professionals, comes great responsibility to stay informed and responsive.

Lee Page, sales director at S&P UK. Copyright: Warren Page. Credit: S&P UK

Let’s take a closer inspection at the Building Regulations which have covered HVAC since 2010 but were significantly updated in December 2021 as part of the shift towards a Future Buildings Standard, as well as EN Standards that have since been superseded.

Important responsibility

With more people now heading back to the office, getting acquainted or reacquainted with Part F of the Building Regulations is a necessity, particularly for landlords and business owners.

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Clause D of F1(1) is a new instruction to monitor air quality in ‘Occupiable Rooms’: a new definition that covers ‘offices, workrooms, classrooms and hotel bedrooms’.

For offices, section 1.32 is new and confirms that 10 litres per second per person or 1 litre per second per m2 floor area – whichever is highest – must be provided.

Section 1.37 is the first specific guidance to “reduce the risk of the transmission of airborne infection” via mechanical ventilation that provides 100% outdoor air to specified levels or incorporates HEPA filters if required.

Meanwhile, the commonly known EN-779 standard defined filter labelling as we know it today (i.e G4, M5, F7) was withdrawn and replaced with the new ISO 16890 in 2018.

This standard defines the required level of filtration depending on environment and application, plus a new labelling format based on efficiency for different particle sizes. A summary of ISO 16890 can be found in the Eurovent 4/23 – 2020 third edition recommendation document.

As an HVAC manufacturer, we use ISO 16890 as a guide when selecting all AHUs to ensure the recommendations are being applied where necessary. Our AHU units, such as the RHE, CADB and CAIB product series, are installed by engineers with filters as standard that meet the minimum requirement ISO 16890: to ePM level 1 70% (F7).

Everyone who works in the HVAC industry faces an important responsibility to ‘do the right thing’ and go over and above the regulations. We just need to ensure that the most up-to-date standards and recommendations are constantly being filtered through so that we’re all on the same page.

S&P UK Ventilation Systems is the UK subsidiary of leading global manufacturer Soler and Palau, and is the sole UK distributor of commercial, industrial and residential fans and ventilation systems.