How this page evolved

Every published version is kept. Each entry shows what changed and why. Earlier versions can be restored by moderators, but only if the material they rely on is still available.

1. Revision 4Oct 4, 2026, 4:09 PMLiveAI-organised, reviewed

   Added newer evidence on real-world retrofit outcomes (New Zealand programme, Canadian retrofit modelling), geothermal heat pumps and thermal networks, and heat pump noise. Reframed the money section around local variability and added guidance on noise, older homes and non-gas heating.

   • · The main finding was rewritten.
   • · Updated “Will it save you money?”.
   • · Added section “What households actually experienced”.
   • · Added section “Beyond air-source: geothermal and shared networks”.
   • · Added section “Noise”.
   • · 4 new sources cited.
   • · The note on uncertainty changed.
   • · The key takeaways were revised.
   • · 4 new pieces of guidance for specific situations.
   • · 2 new open questions.
2. Revision 3Sep 30, 2026, 6:25 PM

   Added NREL's household cost modelling, a comparison of systems and a note on changed US tax credits.

   • · Added section “Will it save you money?”.
   • · 1 new source cited.
   • · Key takeaways were added.
   • · 4 new pieces of guidance for specific situations.
   • · 1 new open question.
3. Revision 2Sep 30, 2026, 6:25 PM

   First brief from the IEA heat pump report and cold-weather field data.

   • · The main finding was rewritten.
   • · The finding is now labelled “evidence” (was “interpretation”).
   • · Added section “Why heat pumps are so efficient”.
   • · Added section “Do they work in cold climates?”.
   • · 3 new sources cited.
   • · The note on uncertainty changed.
   • · 2 new open questions.
4. Revision 1Sep 30, 2026, 6:25 PM

   Created the Sylo.

   • · First published version.