Mike Andrews | Energy Saving Experts
Mike Andrews, Director and founder of The Energy Saving Experts, comments on The Green Register's recent Indoor Air Quality event.
I recently attended The Green Register’s training day ‘Indoor Air Quality, Air Tightness and Ventilation’, and like many of their courses I have attended over the years, I found it an extremely interesting and enjoyable day. My main business is providing Part L calculations, so why would I want to attend a training that on the face of it would appear to be so far removed from I do on a day to day basis?
Like many of the courses I have attended, having an interest in buildings in general and not just the energy side of things, this course provided some much-needed clarification as well as some points for further investigation. I’ve known for a long time that there are distinct links between improving the energy efficiency of a building and the wider topic of ventilation and air tightness. What I hadn’t really considered until now was the importance of indoor air quality, the effect this has on occupants, and how this can be affected by improvements through energy efficiency measures, and dare I say it, poor thought given to ventilation. However, it’s obvious from the speakers on the day that these links – energy efficiency – good ventilation – air tightness - indoor air quality are sometimes not considered when either improving an existing building or designing a new one.
Our first speaker, who was also our third of the day, Ian Mawditt from Four Walls, explained firstly why ventilation is becoming more important. As we improve the energy efficiency of our buildings by improving air tightness, we need to think carefully how we then ventilate those buildings, so that indoor pollutants and moisture are expelled and fresh air is brought in. If we don’t this can lead to a build-up of all sorts of health risks (more of that in a minute) by reduced indoor air quality (IAQ). He later went on the talk about the pros and cons of mechanical or natural ventilation, and the types to consider. Each building needs to be considered on its own merits, there is definitely not a one solution fits all approach.
Derrick Crump of UKIEG, was second up. He told us all sorts of horror stories about the number of indoor pollutants there are, and how these can be controlled at source. For example, Formaldehyde, a common ingredient in many products we use in the building industry, MDF being the main one that springs to mind, is banned from use in countries like Germany, but here there are no controls in the use of it here. We know that it can cause many health problems, so if more informed we have a choice as to whether we use it or not, thus taking away that risk. However, it is just one of many sources of indoor pollution that affects our indoor air quality, and if the building is poorly ventilated, where does that pollution go? Other less formidable sources affecting our IAQ are more benign, cooking, cleaning products, even some of our toiletries (although my teenage son’s deodorant could kill and elephant at 100 paces I’m sure), so maybe not.
Speaking just before lunch was Leigh George from Allergy UK, an information service to help us identify what may be causing allergies and improving IAQ (relative to health issues). She also endorsed products that are known to reduce problems encountered like moulds, dust mites and allergies associated with these problems.
After lunch Kevin Coulting from AECOM presented some examples of commercial buildings and their ventilation solutions, and how even in good design, in practice some things can go unexpectedly. In one such project the night ventilation happened to be working correctly, but with no grills over the open windows, an enterprising squirrel came into the building at night and helped itself to whatever it wanted! In another project, the doors at one of the building being opened almost constantly at the start of the day, were freezing the occupants on reception because the prevailing wind blew directly through those open doors. Ventilation was good, but almost too good! The solution was installing revolving doors, thus not affecting the ventilation, but keeping the temperature up to where it should be.
Lucy from The Green Register talked us through one of the Zero Carbon Hub Guides , the Services Guide, and in particular highlighting the dos and don’ts when installing various ventilation measures. This guide, and the others in the series, were made available to take away at the end of the day.
Our last speaker was Simon Jones from AERECO, a company that manufacture, design and install mechanical ventilation systems. This session was about how to control the systems properly to improve IAQ, which if not done correctly can lead to many different problems.
A highlight of the day for me in terms of information to take away was a short video, available on You Tube, which quickly went through the 4 system types – Natural ventilation with intermittent fans and cross ventilation, Passive stack ventilation, Centralised and Decentralised mechanical extract ventilation (MEV), and finally Mechanical Ventilation with Heat Recovery (MVHR). Very simple but very effective way of showing the main characteristics of each system.
The day concluded with a discussion between the audience and the panel of speakers and specifically looking at the following questions, ‘What levels of ventilation are appropriate?’ ‘What should the balance be between ventilation and source control?’ And,’ What metrics should we use to measure air quality?’ Of course there is no definitive answer to any of those, the building in question and/or the occupants needs are going to vary, but levels of CO2, Relative Humidity and how this affects moisture levels and therefore IAQ, other chemicals etc are important factors.
Like all Green Register events, a fascinating day. Even if sometimes the subject matter may seem unrelated to your main stream of work, there is always something good to learn, and you meet likeminded people too! Mike Andrews – Energy Saving Experts Ltd. Specialising in all aspects of Part L compliance, advice and training. Our new PDF book, SAP - The Essential Guide For Dwelling Designers And Architects, will be available from May 1st via our Website www.energy-saving-experts.com.