It was an interesting meeting today. I realise I cant share any detail due to confidentiality requirements but it’s encouraging that MCS and group members are open to external input.
I’ve been updating the various documentation pages that I’ve written on air change rate calculations this evening to reflect what I wrote above about the use of the EN 12831 ventilation calculation in the new MCS heat load calculator. Updated pages include:
- Heat loss calculation — OpenEnergyMonitor 0.0.1 documentation
- Air change rate calculation methods — OpenEnergyMonitor 0.0.1 documentation
- Heat loss — OpenEnergyMonitor 0.0.1 documentation
Technically the requirement to use the EN 12831 standard for heat loss calculation by MCS (I think adopted in 2012) means that both the older MCS Excel heat loss calculator (in use until December 2024) and many of the popular heat loss calculators are not actually compliant with the MCS MIS 3005 D design standard. I’m guessing that MCS are providing a grace period at the moment given that their own calculator was non-compliant for quite a few years..
This might be useful information for anyone arguing the case for a lower heat loss value in their assessment, but don’t blame the installer, this is more an issue that’s resulted from inconsistent industry guidance.