Conditions were perfect for performing a blower door test on a new build, low energy project I'm working on in Jacks Point with Climate House. For those of you who don’t know what a blower door test is, it’s a method of pressure testing to determine the amount of air infiltration through the exterior of a building. This gives us confirmation of the projected energy efficiency of the project. For further information, have a look at the FAQs on the Passive House Institute NZ website . The bottom line is that, while our building code has an objective of reducing air infiltration and improving energy efficiency, there are no targets or testing regimes in place. For this project, we set a target of 1.5 air changes per hour at 50 pascals. This is the German standard for new build homes with ventilation systems. (Air changes means how many times the interior air volume changes per hour and 50 Pascals is equivalent to a strong wind). We set the blower door up in the door to the garage and then ran the fan at low speed so that we could check for any obvious leaks. This is a valuable step in the process, as it enables you to get the best result from the test. We managed to find a couple of unsealed ducts and plumbing pipes which were promptly sealed up. During the test itself, there is not a lot to do as the process is automated. But for entertainment’s sake, here’s a photo of us standing around, nervously awaiting the test result. |
So how did we do?
I’m pleased to say we achieved 1.35 air changes per hour at 50 pascals and it’s likely that the result will improve before we perform the final test on completion of the project.
Measuring air infiltration is an important part of achieving energy efficiency in construction. Blower door testing is mandatory in much of Europe and is set to become much more widespread in New Zealand.
Measuring air infiltration is an important part of achieving energy efficiency in construction. Blower door testing is mandatory in much of Europe and is set to become much more widespread in New Zealand.