18 November 2014 - Solar powered airtightness test
Thanks to Young Design and Build Greenbuild can now boast to having undertaken a solar power airtightness test!
The house, in County Louth, has a 6 kWp system on the roof, and at the time of the test was producing a little over 3 kW. The 2200 series Retrotec fan used by Greenbuild for the test pulls about 750W when pulling full power - so the power was fully supplied by the sun for the test.
 The house |
 Well sealed too - passive house airtightness |
 Close up of the SMA Sunny Boy inverter showing power production - time was nearly midday |
27 October 2014 - Airtightness Tapes...why not just use masking tape/duct tape?
Sometimes we come across situations while testing where duct tape, or masking tape, or some other non-specialist tape has been used.
If this is to provide a temporary seal for the test, fine - but if it is for the actual airtightness layer, it is not good enough.
To prove this to ourselves, we undertook a little experiment - while not full of scientific rigor, it is clear enough for us:
The prinicpal of Greenbuild, Gavin Ó Sé uses insulation boards to conserve heat and keep out light from the house windows at night. To prevent the silver foil of the boards from cutting hands while placing the boards and taking them down, some of the boards were taped at the edges using duct and masking tape while others were taped with one of the lowest priced 'proper' airtightness tapes on the market. We are not specifically recommending this tape - but note that it is cheaper than most others on the market. It costs little more more than a good duct tape, and is only 50mm instead of the 60mm normally recommended for best results, yet you can see from the pictures how the stick and quality of that tape remains high compared to the non-specialist tapes over a time period of about 2 years.
We know the specialist airtightness tapes and the other tapes are not made for use in situations where they are subject to constant movement and pushing together, as happens with these boards every day and night as they are set up and brought down - but we feel it is a good indicator of how we can expect the tapes to perform when out of sight inside the building's hidden layers.
 The state of masking and duct tape after about 2 years |
 The state of a specialist airtightness tape - and this is one of the budget ones |
 Close up of the masking/duct tape |
 Close up of the airtightness tape used |
01 April 2014 - Site toilets
Some builders seem to want to save any brass farthing they can, regardless of the regulations that would require otherwise.
When it comes to on-site sanitary facilities, we have been glad to see things have been improving, but it hasn't reached all builders just yet...
 For example, this is absolute luxury compared to... |
 This! This is not a set up for April fools day! This is how it was. And it has not been the only one like this. |
20 Feb 2014 - Airtightness Testing - The bar is being raised (or is it lowered?)
Recently, Greenbuild has been priviliged to test two very airtight dwellings.
Less than 0.10 ACH?
Congratulations to Roman Szypura of Clioma House who has achieved an airtightness rate on a timber frame new build of under 0.10 ACH @ 50Pa. Although he was chuffed on the day of the test, he was also relieved!
 House with an air change rate of under 0.10 ACH |
 Fan seems a bit oversized for this type of work, no? |
The second testing record for Greenbuild was for an Enerphit project being undertaken by Young Design and Build - a phenomenal result that is better than many a new build Passive house!
 Renovated house with an air change rate of under new build Passive house standard of 0.60 ACH |
 Again, we ask ourselves why we use why such a big fan with only a few little holes left open - we will have to review our equipment inventory at this rate.. |
