[tgsovlerkhgsel]

> the theory being that warming up a cold house in the morning costs more energy than maintaining a stable temperature

This is only true if the heating happens quickly and the system is less efficient when heating quickly. Otherwise, this doesn't make sense from a physics standpoint. A temporarily lower temperature differential means less kWh of heat lost.

[DamonHD]

This is a whole research topic, my PhD in fact!

FWIW I run my heat pump intermittently and with locally-smart TRVs that get to call for heat centrally, and a weather compensation only flow temperature curve, and it WORKSFORME!

https://www.earth.org.uk/heat-pump-16WW-control.html

[subscribed]

Fascinating read.

Certainly feels like I'd need PhD from it to successfully install, modify, calibrate and run the installation until its fully adjusted, for the peak comfort and minimum cost/dirty energy use.

[DamonHD]

I am putting my efforts into making that not be true, at least for something "close enough" to peak comfort/efficiency/whatevs for any nominal shortfall not to matter in real life.

The obsessives amongst us can continue to tweak if we wish...

[anotherhue]

I enjoyed reading this, thank you.

[DamonHD]

\o/

[jmilloy]

I think that maintaining a stable temperature means warm walls/floors/furniture and potentially cooler air temperature, as opposed to a cold house with intermittently warm air. Most people can feel comfortable at a lower thermostat (air) temperature if the walls etc are warm due to maintaining a stable temperature. I don't have calculations or references, YMMV.

[adrianN]

Heating systems generally are more efficient when they need to output less power. Whether that cancels the increased heat loss seems to be a question that can’t be answered in general.

[Suppafly]

>Otherwise, this doesn't make sense from a physics standpoint. A temporarily lower temperature differential means less kWh of heat lost.

This topic comes up anytime thermostats and heating are mentioned. The physics arguments only makes sense if you don't care about comfort. Most people would rather optimize for comfort with some energy/cost savings if possible and the physics folks seem to not care about comfort at all.

[rightbyte]

"Quickly" implies higher power which will make the air around radiators warmer than a slow heating.

The losses are proportional to the temperature differential between outside and inside.

So you should have somewhat higher losses from the hotter air streams from the radiators passing the windows.

Dunno about magnitude though.