The technical overview for the NZ Green Building Council Energy and Carbon Calculator for Homes is now available. The guide was put together by me and NZGBC’s Sam Archer. It’s a free download, available here, plus there’s general information about the guide here.
We developed the first version of ECCHO in Excel using PHPPv9 as the engine, then Sam Archer built an online version in Python. As part of the NZGBC team’s drive for better performing homes, education and transparency, they produced this technical overview to help users understand what’s going on under the hood of the Homestar ECCHO models.
Because ECCHO uses the same conventions and methods as PHPP (v9.6a), designers can go looking there for technical details. But ECCHO is designed to be simpler and easier to use for those who aren’t qualified Passive House designers so this new technical overview fills the gap.
It was a difficult balance to choose how much detail to put in the manual and how much to leave out, which we resolved by creating some extended technical footnotes and appendices.
For the building science über-geeks, ISO 13790 has been replaced by ISO 52016. The new standard has some awesome new features, but the annual heating/cooling demand predictions for single-zone residential dwellings are nearly the same. I’ve run the numbers in a few projects to check for compliance with ASHRAE 140 for the NZ Building Code.