Environment, energy, sustainable building
Moisture in buildings harms the health of the occupants, and often damages the fabric itself. It is important in the design of retrofit insulation, but also, an issue wherever ventilation is inadequate
This 150-odd-year old historic stone warehouse in the centre of Cirencester has been very carefully converted to create a youth hostel, providing much-needed budget accommodation in this pretty Cotswold town.
An Enerphit retrofit lifts the comfort way above the usual draughty-old-house-that-was-impossible-for-the-owners-to-heat that may be many people’s experience of UK youth hostels. Continue reading “Cotswold stone warehouse becomes Enerphit hostel”
An AECB consultation response
This document was written in response to a NICE (National Institute for Health and Care Excellence) 2014 consultation on producing guidelines for health authorities on tackling excess winter deaths and illnesses. It was written (mainly) by me, on behalf of the AECB, teaming up with Severn Wye Energy Agency and the STBA (Sustainable Traditional Buildings Alliance) – who also contributed information.
While at the time of this consultation the deleterious impact of cold living conditions on health were well known – prompting the consultation – poor indoor air quality was less discussed.
Yet of course, air quality can be very poor in cold homes: people will block out any draughts they can – including the intended fresh air supply from a ventilation fan or vent – especially if they are in fuel poverty. This only increases the risk of condensation and mould – already high in a dwelling with cold, uninsulated surfaces. And more and more evidence is piling up of just how bad mould in particular is for people’s health and wellbeing. Continue reading “Cold is not the whole story – what the health services need to know about housing”
Natural ventilation often fails – but what is the evidence that mechanical ventilation succeeds? – Investigation for Passive House Plus
There have been a number of studies showing that natural ventilation, dependent as it is on random gaps in the building fabric and the vagaries of wind and weather, is not a reliable source of fresh indoor air. (see here for my article on this)
In theory, mechanical ventilation is under more control, and should work more reliably. But does the evidence bear this out? Does mechanical ventilation deliver good air quality in practice?
I looked into the research to find out whether MVHR, in particular, lived up to the ideal. Continue reading “A look at the evidence on mechanical ventilation”
A well-designed and well-executed retrofit will not only save energy, it should offer a more comfortable, healthier indoor environment, and protect the building fabric as well. However, there have been a number of warnings about what might go wrong – sometimes, even suggestions that in some instances retrofit measures should not be undertaken at all.
Are these warnings justified? What might go wrong? What is the evidence in practice? In this article, first published in Green Building in 2015, I look at some of the concerns, examine the reasons behind them, and suggest ways to protect building and occupants so retrofit really delivers.
Risks of retrofit – article from Green Building Magazine
Slides from my presentation to the 2014 AECB annual conference on ‘Natural ventilation – does it work?’.
Download pdf – Natural Ventilation – talk for AECB 2014
For my article on the same subject, see this link:
Natural Ventilation: Does it Work? Article for Passive House Plus magazine
I’ve had a couple of requests for links to the sources for “Natural Ventilation – does it work?”, my article for Passive House Plus Issue 6 (start of 2014), so here is a list of most of them – live as at the time of posting in April 2014, but no guarantees they will remain so of course. Continue reading “Does Natural Ventilation Work? – References and Links”
While mechanical ventilation is sometimes perceived as problematic, expensive and possibly even energy-guzzling, natural ventilation often seems to be seen as – well – “natural” – a safe, old-fashioned, reliable default solution. In this article for Passive House Plus I had a look at this assumption.
Theoretical modelling suggests that natural ventilation is likely to be rather unreliable, with the same building at risk of both under- and over-ventilation under different weather conditions. But what happens in practice?
The first problem I had was finding some data: there is very little of it.
In the studies I was able to find, it turned out that indoor air quality in naturally ventilated homes (including levels of relative humidity, oxides of nitrogen, and volatile organic compounds, for example) is not what it should be. (I also found some studies from schools raising similar concerns, but there wasn’t room to write about these as well).
For example, a study of 22 homes built to the 2006 Part F regulations for ventilation found that about half of them failed to achieve their recommended background ventilation rate even with all vents open/fans running as intended; pollutants exceeded the guideline levels in a number of them.
But what was really worrying was that when the researchers first arrived, they found that many of the vents were closed, and many of the extract fans (both in bathrooms and kitchens) had been disabled at the isolator. Similar findings appeared in all of the studies I was able to track down. Continue reading “Natural ventilation – does it work?”