Category: favourites

Can I fit a heat pump? What do I need to know?

At the start of 2022 we finally got rid of the gas supply to our home, and retrofitted an air source heat pump. With the high proportion of renewables in grid electricity now, this has led to an absolutely huge cut in our household carbon emissions, and we are delighted with how it has performed so far.

picture of a heat pump
Our Mitsubishi Ecodan

While we were planning this, I wanted to know more about what the process entailed and what we would need to think about – so I decided to write an article about it. I learned so much that I ended up writing a two-parter. Continue reading “Can I fit a heat pump? What do I need to know?”

A leaky fabric is no substitute for ventilation

In some corners of the construction community there is still a lurking belief that a leaky fabric is needed in order to ensure good indoor air quality.

But gaps and cracks are random, and the air flow through them, even more so. Believing a leaky fabric will contribute usefully to indoor air quality is an act of blind faith. Continue reading “A leaky fabric is no substitute for ventilation”

Welcome

Welcome to my site – a collection of some of the articles and resources that I have written or contributed to.

Generally you will find a summary on here, and then a link to the article/resource, wherever it was published.

If you want to get in touch, see the ‘about me’ page under ‘about’.

(note: posts appear in the order I add them here, not the order of original publication, but hopefully by using the categories  in the menu or the search function, you can find what you are looking for)

Preston (and other) failed retrofits on Radio 4

The story of the failed retrofits in Preston, along with similar issues faced in Blackpool and – this time, with cavity insulation – in Leeds, were covered in an item by Zoe Conway on the BBC Radio 4 Today programme. I helped Zoe with some background, but she did a lot of work visiting the sites and interviewing occupants, and I think this was a pretty fair account.

The report can be heard here, until the beginning of December: https://www.bbc.co.uk/sounds/play/m0001282 -starts at approx 1hr 33m.

The Radio 4 item was also picked up by Mail Online later that day.

You can read my original post, which includes a link to my article in Passive House Plus,  here

 

 

Cold is not the whole story – what the health services need to know about housing

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”

A look at the evidence on mechanical ventilation

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”

Electric Heating – time to come in from the cold?

While there are well-established technologies to produce electricity without fossil fuels, decarbonisation of heat is struggling to get under way. Recommended strategies include expansion of low carbon networked heat and possibly the decarbonisation of gas – though these are still only happening at a scale (and with dubious carbon credentials, see PH+ Iss 15 – district heating). However, the commonest proposed means for decarbonising heat is via electrification.

Electrification of heat raises a number of questions about the ability of our power systems to produce enough low carbon electricity and their capacity to transmit it.  But it also represents something of a u-turn in building services design. Continue reading “Electric Heating – time to come in from the cold?”

District Heating – does it work with Passivhaus?

Cost effective district heating schemes need a nice dense energy demand. They also involve a lot of circulating hot water, which with the best will in the world, is going to involve continuous heat loss. Highly-insulated low energy buildings need very little heat – and in the summer, heat gains can be a positive menace.

So can the two work together? I explored the question a bit in this article for Passive House Plus – downloadable here as a pdf.

District Heating – does it work in Passivhaus?

Deep retrofit – the big prize?

Simple home energy efficiency improvements (such as new boilers, cavity wall insulation etc) can bring valuable comfort and health benefits to the occupants of inefficient homes – especially those in fuel poverty – as the last article revealed (see here). However, energy, carbon and bill savings tend to be modest, rarely topping 15% or 20% – and sometimes energy use actually increases!

If housing is to contribute its share of the 80% cuts in carbon emissions this country is committed to, in order to play is part in tackling climate change, retrofits will need to go deeper – a lot deeper. But will occupants benefit from the extra work? And is it affordable? Continue reading “Deep retrofit – the big prize?”