Airedale News


HTM 03-01 new guidelines for AHUs

On the 22nd of June 2021, the revised Health Technical Memorandum 03-01 (HTM 03-01) – Specialised ventilation for healthcare buildings, was released by NHS England & NHS Improvement. The HTM 03-01 provides comprehensive advice and guidance on the legal requirements, design, installation, maintenance, and operation of specialised ventilation in healthcare premises.

HTM 03-01 legislation for healthcare indoor air qualityThe importance of ventilation, indoor air quality and their associated health benefits have been steadily growing as a topic of interest as we, as a society, have learnt more about the impact of pollution on our wellbeing. With the emergence of Covid-19, we have all had to take measures to stay safe, and this has seen interest in IAQ surge. As we understand more and more about the role that ventilation can play in reducing the opportunities for airborne virus to spread, the demand for renewed formal guidance has also grown.

At Airedale, we all welcomed the publication of the much anticipated Health Technical Memorandum 03-01 (HTM 03-01) revision by NHS England & NHS Improvement. Originally published in 2007, these guidelines bring a much-needed step-up in the requirements for healthcare ventilation in the UK. Developed with the support of the CIBSE Healthcare Group, the document brings together the advice and recommendations from a wide range of building services engineers with specific interest in the healthcare sector as well as many others involved in hospital ventilation, to offer best practice solutions.

When these guidelines were published they became instantly effective. All work in progress now needs to meet the requirements of these new guidelines and whilst that can be a bit of a headache when you are well on your way to completion, I would imagine most reputable AHU manufacturers who understand the UK market place will have been pre-empting these revisions and should be able to incorporate any unforeseen changes fairly fluidly. That said, as a consultant working on a healthcare project, or FM responsible for a healthcare facility, you should absolutely check that the unit you are installing meets the updated requirements. This gives you longevity in your investment, as well as meeting the required indoor air quality (IAQ) standards.

Meaningful Change

If Covid-19 has done anything positive, it has at least bumped IAQ up the priority list. At Airedale, we have seen a surge of requests for advice on the maintenance and control of air handling systems. There is also increased demand for spares from building owners and facilities managers, worried their systems might not have been maintained up to the standard required to be effective as the world starts to open up again. This, along with the publication of the revised HTM 03-01 guidelines, means many more healthcare organisations and commercial building owners are in a position to hold meaningful conversations about IAQ. They can then be given the resources to make the refurbishments, adjustments or investments needed to upgrade plant equipment.

Of course, it is important that this increased awareness and concern about ventilation systems does not become just a passing trend, but that it leads to tangible action and change in how these are seen in the eyes of those who design, manufacture, install, maintain, and use them. We are certainly glad that government regulators are re-thinking the existing design approach and taking action to improve on the current guidance.

Alongside the pandemic-induced increase in interest in IAQ, is the 2020 government announcement that 40 new hospitals will be built by 2030. This is part of a package worth £3.7 billion, delivering on their commitment to improve the UK healthcare infrastructure in the face of the COVID-19 pandemic and Brexit. This has led to a significant increase in demand for HTM 03-01 compliant air handling units, and we are aware that the recent changes in the guidelines has left the industry somewhat playing catch-up.

HTM 03-01 CPD

As leading manufacturers of air handling units for the healthcare sector in the UK, we sank our teeth into the new documents and have dissected the new guidance. Not only to recognise and acknowledge the changes, but also interpret them into some sort of meaningful, digestible form as to what it means to our industry. Which changes are essential? Which are recommended? What value engineering options are there, if any, and most importantly, what do the changes mean to our clients?

At this point I am very tempted to rattle off the changes and debate the ins and outs of them, but I fear it isn’t something that can be done so well in a blog post and lends itself better to a conversation. Given the immediacy of the changes, and urgency of getting up to speed with them, many of our existing client base have requested a CPD, so this has been developed as a one hour session and is available to anyone who feels they would benefit from a summarised, more conversational look at the changes and what they mean to them right now, and the industry in general longer term.

Summary of AHU guidelines

I have listed below a brief summary of the changes for air handling units, for those unsure if the CPD would be relevant to them:

  • General refresh of the existing standards and regulations including the eco-design directive for ventilation products (EU 1253/2014)and updated filtration standard ISO 16890
  • Updated maintenance and service requirements.
  • Selection of appropriate build materials to avoid corrosion, growth of microorganisms and condensation.
  • The implementation of energy efficient solutions for air movement, heat recovery and controls, covering newer technologies and highlights their importance in achieving a sustainable design for the system.

Anyone familiar with the HTM’s knows that while some of the guidelines are straightforward, there can also be some ambiguity and the guidance can be somewhat open to interpretation. The new version of the HTM 03-01 still contains many areas of discussion and its execution should therefore be discussed carefully and objectively. This is the main reason we decided to come up with a CPD which will allow us to both inform and open a dialogue with professionals in our industry.

In conclusion we very much welcome the heightened interest in IAQ and we hope the publication of the new HTM 03-01 guidelines will keep that conversation going in the right direction. We do however appreciate new legislation and documentation that has to be implemented with immediate effect can create extra work to a time-poor industry. Our experience and knowledge of the ventilation requirements in the healthcare environment affords us insight into the interpretation of these documents and we are very happy to share that with you, in a succinct, webinar-based CPD format.

The HTM 03-01 CPD is available, free of charge, to any industry professional who might benefit from this information. Those interested in booking a CPD session can email us at or call on 01207 590575.

Author: Bruno Guedes, AHU Product Manager

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