This page collects discussion on practical heating / energy saving advice, including controversial issues.

Heating by electricity

Generally, generation of electricity has only 30-50% efficiency.
However, using electrical device on well-defined time slices can be more efficient than heating an entire room.

Shall I use an electrical radiator / convector?

Local electric heating (e.g. heatfans) can be used to quickly warm up the space you are currently in. This can be more efficient than maintaining comfortable temperature in every room most of the time, and hence save gas and money.
Blackout due to heat fans? Rather unlikely:
- If all 650.000 heatfans bought in 2022 will work at max power simultaneously, they would generate additional power demand of 2 kW * 650.000 = 1.3 GW. This is less than 2% of the typical electricity demand in Germany (70-75 GW in winter peak-time).
- In their recent stress test, German grid operators estimated additional demand due to heat fans between 1.5 GW to 2.5 GW. This is +3-4% peak demand.
- At least in new buildings, there should be 10 kVA (~8 kW) power per flat available: [1] [2]. This is enough for two typical heat fans running at max power, plus one large consumer (dishwasher/microwave/washing machine), plus all regular household devices (TV, lights, PC etc.)

With installation
- "Classical" heat pump: https://www.youtube.com/watch?v=MFEHFsO-XSI
- Cheaper & easier: AC heating / Heizen mit Klimaanlage
Without installation (for tenants / Mieter)
- Heat blanket / Heizdecken
- Portable AC (?): https://www.youtube.com/watch?v=aYHQzQQwSn4
- Infra-red heating: https://www.youtube.com/watch?v=qw4X44h2Jk4
- Convectors
- Heat fan / Heizlüfter
- in principle, electrical heatings cannot be inefficient, as every use of electricity generates heat (e.g. you also could mine bitcoins, or alternative, support writing this wiki on your computer)