heatloss.js example

See linked resources at the bottom for more information on how to use this tool

How to use this tool

Example calculation and discussion: A mid terraced house
(Typical design temperature heat loss, heated neighbours, average January wind speeds and air change rates.)

This tool is based on the BS EN 12831:2003 heat loss calculation standard:
Room by room heat loss using MCS heat pump calculator

There are a number of useful resources available on the MCS installer standards and tools page (see under Heat pump section), including U-value and heat emitter guides: MCS installer standards and tools

MCS Guidance on U-Values from Domestic Heating Design Guide

To generate a more accurate degree-days value for your location see: https://www.degreedays.net/

This tool is open source and free to use, the source code is available on github: https://github.com/trystanlea/heatlossjs

You may also be interested in SAPjs, a tool for household energy assessment based on SAP 2012: https://openenergymonitor.org/sapjs