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Wirksworth CLT – seeking the heat!
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By Roger Shelley
Since the start of the colder season, the Community Land Trust’s intrepid volunteers have been seeking out the heat escaping from local homes...in an attempt to help householders plug the gaps!
Armed with an ingenious FLIR C5 thermal imaging camera (just the size of an ordinary digital camera) we have been out responding to enquiries from people who are keen to find out where they are losing heat from their homes. We were lucky enough to receive a grant from the Better Derbyshire Dales Fund and the Post Office Lottery for the camera.
It takes two images simultaneously, one a conventional digital image for reference purposes, the other exactly the same view, but with the temperature of objects represented in a range of colours from dark purple/blue (coldest) to yellow/ orange/white (warmest). For best results there should be at least a 10 degree C variation from inside to outside the property.
There are certainly pitfalls and we are learning all the time – it’s important to avoid taking pictures which include people, because they skew the temperature upwards, as do working radiators. Some shiny surfaces have strange effects too – so mirrors and reflections in windows are best to avoid.
Outside, it’s important to try and reduce the amount of sky in shot, otherwise you end up with an average temperature which includes that of the Milky Way! It’s fair to say that external images are harder to interpret because there are so many more variables.
Here are some examples:
The digital image on the left is of a loft, with insulation piled up around some wooden supports. On the right is the thermal image, which shows - yellow is warmer - that heat is escaping from the room below through some gaps in the insulation at the base of the supports..
Below, heat is escaping at the edge of the ceiling where it joins the wall - you can see missing insulation showing as purple, eg.
Showing heat loss from the wall, skiring board and floor edges in a Victorian house– a common problem.
A kitchen door – showing the thin 1970s door panel which may be leaking heat as much as the glass.
And an uninsulated loft trap door – compared to the insulation in the loft around it.
Having gathered this valuable data, we then record information from the householder and attempt to build up a picture of how the house is performing thermally. suggesting possible solutions which will keep the heat in. It’s important to say that we are not experts, but quite often we are able to confirm and show what people perhaps already suspected – but with actual photo evidence.
Common findings are missing insulation in lofts, heat loss from around external door frames and windows (even modern double-glazed window units - because when the frame was inserted into the wall, gaps were left for heat from inside to escape .)
It’s really evident that thick, well-fitting curtains help retain heat in winter months, as do some well-fitting shutters and blinds. Thick underlay under carpets also helps too, especially with suspended floors, eg over cellars.
We have had 16 requests for surveys and completed 10 of them, with the remainder still being processed. Properties have ranged from Victorian detached to 21st century social housing . We intend to compile the information into a suitably anonymised set of case notes so that others can learn about some of the issues too.
Over the summer, when it is not possible to use the thermal imaging camera, we will continue to visit householders to discuss energy efficiency and ways to use less energy and lower the bills. Contact us on wirksworthtclt@gmail.com
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MORE ON MARY ANN'S RETROFIT
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Progress at last!
By Mary Ann Hooper
In previous issues of the newsletter, I described how my early retrofit project in 2011 had some errors revealed when I took some thermal images with our new CLT camera. I had installed loft insulation and external wall insulation but the camera showed that the eaves were leaking heat on all four sides of my bungalow. I hadn't realised that the loft insulation didn't join up with the external wall insulation, so it formed a 'thermal bridge' of cold.
In January, work finally started. What the builders discovered about the insulation installed in 2011 was quite shocking. My receipt for the work says the insulation installed was 270mm thick, but in fact it was only 200mm thick. The insulation was especially badly fitted at the eaves and only went as far as the beam, so there was a large uninsulated area beyond it. In the photo, existing insulation has been removed from one space between two joists, and you can see where the insulation ended in the two adjoining stretches.
 Pushing more insulation far into the eaves risks cutting off necessary ventilation of the attic, so to ensure ventilation, a slab of solid insulation was laid on top with a space left for air to pass over. (See the architect's drawing.)
The other half of the project was to install a wedge of insulation at the join betwween the wall and the ceiling of the room below. This is meant to supplement the decreasing amount of insulation that can go into such a small space over the top of the external wall insulation. In the drawing on the right the insulation has curves. The wedge is at the bottom left. Above it in the loft is the existing insulation pushed into the eaves. Above that is the strip of solid insulation which leaves a small gap above it for ventilation. (The external wall insulation is vertical at the bottom right.)
I have thermal images from before and after:
Pre-retrofit -the lounge corner Post-retrofit.
 
 On the left is the photo which shows the wedge of insulation along the external walls. The thermal image above shows it is losing much less heat now.
I have been keeping a record of my use of gas in kilowatt hours for heating. I expect to see it go down, by how much I have no idea. It's the carbon emissions that are being reduced which is my priority.
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A sustainable Wirksworth
Richard Rowlatt, one of our trustees, has a vision for a sustainable Wirksworth. Would you like to help with his project? Email him on r.rowlatt@btinternet.com.
Wirksworth needs a building firm specialising in the installation of renewable energy equipment.
A house must be thoroughly insulated, damp-proofed and draught-proofed before equipment such as solar panels and/or heat pumps can be fitted. For an old house this is an expensive and disruptive exercise, chaotic and beset with pitfalls.
When retrofitting an old house the following are often lacking
- An unbiased surveyors opinion
- Skilled craftsmen
- High standards
- Teamwork
When installing equipment there is:
- A national shortage of qualified technicians
- Firms supplying equipment may subcontract to cowboy outfits who do a shoddy job and disappear
- A national shortage of equipment
- Shortages of sophisticated equipment such as heat pumps cause delays
A tangle of red tape!
It boils down to lack of:
- Planning
- Teamwork
- Standards
This can can only be rectified by bringing the whole operation under the control of a specialist building firm.
A renewable energy co-operative could devise a business plan and raise a proportion of the considerable start-up capital needed to acquire the necessary land, buildings and equipment and to hire the workforce.
A consortium of suppliers and manufacturers could provide start-up finance.
The co-operative could expand until Wirksworth is self-sufficient in renewable energy.
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COMING UP IN THE NEXT FEW MONTHS
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We are planning to run another Open Ecos Homes weekend in the early summer.
Come to our stall at the 1 April Farmers' Market for useful information about retrofitting.
Help us reach more people locally - we offer a way to tackle the climate crisis here in Wirksworth by doing something practical.
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Heat pumps are too expensive and complicated...
A Lords Committee is criticising the UK Government for poorly designing a grant scheme giving homeowners £5,000 towards heat pumps, arguing that the technology is still “impossible” to access for low-income homes.
Click here for more
Trustmark has updated its information on retrofitting – much better than earlier CLICK HERE
Request your free, remote energy assessment today,
HERE
Ashden Innovator Awards! Click here.
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Our Board
Noel Mayes (Secretary)
Mary Ann Hooper (Chair)
Alison Clamp (Treasurer)
Mike Whittall
Richard Rowlatt
Pam Taylor
Roger Shelley
Vacancies: 3
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