MCS updates Heat Load Calculator
UK – The Microgeneration Certification Scheme (MCS) has published an update to its Heat Load Calculator (HLC).
The HLC is an online tool that helps MCS-certified low-carbon heating installers complete a BS EN 12831-1: 2017 compliant heat load calculation, supporting the requirement in the Heat Pump Design Standard (MIS 3005-D) and the Biomass Installation Standard (MIS 3004).
Since its launch in December 2024, MCS has worked with industry to refine the tool, including hosting regular meetings with members of its Heat Pump Technical Working Group and Elmhurst, the heat load calculator software developer. MCS has also collated feedback directly from HLC users to ensure the platform continues to be fit for purpose.
This has informed the latest improvements to the HLC tool.
What are the changes?
The following changes are designed to help heat pump installers to use the HLC to help meet MCS requirements:
1. Removal of references to heat emitters in the final report
2. Lists the 99.0% dry-bulb temperatures
3. Removal of old excel version of the HLC
4. Air change values (ACH)
5. Air permeability defaults
6. External design temperatures added for Jersey
All of the required inputs to complete a calculation in the tool remain the same, however the technical assumptions and values have changed as listed above – unless installers choose to override them.
For calculations that were in progress at the point of update, all progress up to that point will be saved, however, you may receive various errors and not be able to finish the calculation as a result. To resolve this, you need to close and re-open their browser so that the calculator can update to the new version. All calculations completed using the tool will be compliant.
MCS worked with Elmhurst to develop a process of logging changes made to the tool, which is also included in the update. The calculation summary will include a reference to which version of the tool was used for each calculation report.
MCS says it will continue to work with the Heat Pump Technical Working Group and wider industry to review industry best practice, including the changes to the CIBSE Domestic Heating Design Guide, to ensure both the HLC and the associated standards are kept up to date.
For more information, contact [email protected]
