Makeup air in a Passive House

Here’s a good summary on make up air for rangehoods, from HVAC consultants and designers at Energy Vanguard. It’s worth reading in full. The quick summary goes like this: Good kitchen cooktop installs position the cooking hood against a wall, and it fully covers the cooktop. In such a case, 125 L/s or 425 m3/hr is sufficient for a normal …

Passive House design training relaunches, on-demand format

New Zealand needs more Passive Houses—and other buildings heading in that high-performance direction. That requires more confident and skilled Passive House designers. Sustainable Engineering last year launched a new training course, designed to make the Passive House design process more practical, predictable and straightforward for the designer, architect, builder and client.  The course was very well-received and now it’s back, …

Detailed LCA resource available

The Buildings and Communities Programme (EBC*) has just published a huge resource of LCA work focused on buildings in Europe.  The focus of the research are heavyweight buildings powered by a grid that is less clean than New Zealand’s. I’m not sure how New Zealand’s metrics for embodied carbon emissions across the different stock levels will be set. It becomes …

MVHR inlet/extract positions

There’s some new advice available about locating the air inlets and exhausts in MVHR systems. If you’re a Passive House designer or otherwise involved in high-performance building, it’s important to keep up with the technical changes, as best you can. ASHRAE’s latest publication* has pulled together research and studies (including CFD work) in order to offer advice on the location …

TFA or CFA? The difference matters

Anyone who notices there are fewer biscuits in a packet that is outwardly the same size has encountered shrinkflation. Same price, but nine chocolate biccies instead of 11 means 18% less treats for your money. It’s not lying but it is confusing. We’ve got to watch out for shrinkflation in relation to building performance. A Passive House designer recently claimed …

Understand thermal implications of underfloor heating

Embedded under-floor heating is a luxurious way of keeping a house warm. You may encounter clients who hate heat pumps and who aren’t deterred by the cost of under-floor heating. But there’s some implications for a high-performance design that architects/designers must be aware of. Passive House buildings by definition have a very low heating demand. Heating the slab is an …

Thermal bridge calc error rate is way too high

I estimate nearly half the thermal bridge calculations we see during pre-construction review are wrong. Newly minted Passive House designers and consultants are not wholly responsible. The Sustainable Engineering Ltd team is finding errors in the maths provided by experienced designers too. Lifting skills and confidence in thermal bridge modelling—and slashing that error percentage—is our motivation for organising an online …

Q&A: Is spray foam insulation a good idea?

Q. What’s your opinion about spray foam insulation for New Zealand homes? A. Spray foam can be used with good results if properly designed and installed well—but a successful outcome requires both of these or a lot of luck. In the UK, there have been enough problems with bad installations of spray foam in retrofitted roof insulation that it impacts …

MBIE releases technical guidance on operational carbon

I welcome the release of technical guidance for operational carbon calculations by MBIE, as part of its Building for Climate Change programme. There is lots of work ahead of us but it’s an important step to have a document to argue about now. In short, the methodology calculates energy use by predictive energy modelling and uses a badness factor (annual …