The Leak Detective

The kits are available to borrow free of charge for a period of two weeks. Armed with a few DIY tools you can conduct your own home energy survey to pinpoint problem areas – and test whether work you’ve carried out has paid off!

Public libraries in Dublin city are now offering you the possibility of hiring out not a book or a DVD, but a Home Energy Saving Kit, courtesy of Codema (City of Dublin Energy Management Agency). The kit allows you to monitor energy use in your house; Caitriona Fisher, whose house you might remember from our Winter 2015 issue, agreed to take on the challenge and test her very own home which was beset by high humidity and poor insulation levels up until the time she renovated. The burning question is whether all the hard work she invested in has really paid off.

The Kit

Caitriona’s two favourite devices were the leak detector and the temperature/humidity reader, which allowed her to gauge the effectiveness of her insulation and ventilation strategy.

Temperature and humidity meter: With this piece of kit you get to confirm what you already suspected: if the house feels damp it probably is. Reasons for high humidity include poor ventilation systems, insufficient heating, lack of insulation and low indoor air quality. Ideal humidity levels are between 40% and 60%. Low temperature can be due to insufficient insulation or heating system; draughts and poor window quality can also be at cause.

Thermal leak detector: A digital thermometer which shows you temperature differences within a room – this pinpoints where there may be thermal air leaks, e.g. around windows, and identify areas for further insulation and draught proofing. The difference between the temperature of a surface and your room should be no greater than 5 degC. When you turn on the device it sets the reference temperature automatically, and, depending on what you are pointing it at, the LED light on the device will change colour if it detects colder or warmer
temperature changes.

The Verdict

It was with some trepidation that Caitriona opened the kit; the last thing you want after investing a lot of money in a refurbishment is to be told it was all for nothing! Discouraging is too small a word.

But thankfully the readings, which were taken in April, showed that the additional insulation that was installed in the internal walls paid dividends (calcium silicate boards on lime rendered walls) as temperature differences were not high. In most rooms these came back at around 1 degC. Maximum temperature difference in a room was 2.6 degC, which, despite being a south facing room, had not been insulated as part of the renovation. The humidity level however was good at 50%.

The subfloor was also ventilated and insulated as part of the works undertaken two years ago; the humidity levels are much improved (50%) as compared to when dry rot was present (95%). The temperature differences (2.2 deg C) in these rooms, i.e. in the living and dining rooms, and humidity levels (54%) are the highest but still within acceptable bounds.

Caitriona is considering insulating her walls in these rooms but as the building has historic value this would mean having to insulate on the inside, as they did in the bedrooms, and this will lead to making the rooms smaller.

The back bedrooms, which are upstairs and east and south facing, were insulated and have the lowest difference in surface temperatures which is obvious in how comfortable they are.

Caitriona says she will repeat these readings to see if the good results are maintained after the summer and into the winter.

Other Tools

Part of the kit is also a plug-in energy monitor to show you how much electricity appliances use, a radiator key to bleed your rads (should be done once a year; having to bleed often can be a sign of a leak), a stopwatch to test the flow rate of your taps and shower, and a fridge/freezer thermometer – did you know you should keep your fridge between 3 degC and 5 degC and your freezer between -15 degC and -18 degC? With this device you can set your food storage appliances correctly.

The Home Energy Saving Kit is currently available for the public to borrow free of charge from 10 Dublin City Public Library Branches.

To find out more about the kit and for a list of branches where they are available, visit 

Update March 2017: The Home Energy Saving Kits are now available from all Dublin City libraries and libraries in Leitrim, Roscommon, Cork City and some parts of Galway. The kits are available to borrow free of charge for a period of two weeks.

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About Astrid Madsen

Astrid Madsen is the editor of SelfBuild & Improve Your Home magazine. She previously held the same role in an Irish trade publication, before that she worked at the National Standards Authority of Ireland. She graduated with a BA in Urban Studies from Columbia University in New York and holds an MBA from the Instituto de Estudios Bursatiles in Madrid. France of origin, she now lives in Portarlington, County Laois, where she's taken on the task of renovating a listed building! Email

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