At what outside temperature should I turn on the heating?

Energy prices are rising and temperatures are falling. When looking at the weather and the approaching autumn and winter, many ask themselves: turn on the heating Or would you rather throw the blanket around your shoulders?

There is no clear answer to the question of when the radiator should be turned on, but fortunately there are a few guidelines that can be used as a guide. Especially that Age of the building and desired indoor temperature are good starting points.

Heating is important – otherwise there is a risk of mold

Actually, the heating period is roughly from October 1st to March 31st, but people in this country often start to shiver as early as September – no wonder when it’s stormy and raining outside and the temperatures drop well below 20 degrees. As an Eon survey from 2020 showed, most Germans turn on the heating when the average daily temperature is below 15 degrees Celsius – but does that make sense?

When it comes to the question of whether you should heat, it is not only your own perception of heat that is decisive, but also the building fabric. If you heat too little, consumption falls in the short term, but in the long term you damage the building. When rooms cool down, the humidity increases and moisture condenses on walls and window frames – but also on furniture. This quickly leads to mold. In winter, there is also the fact that rooms with water pipes should not cool down too much. If the temperatures fall below freezing, there is an acute risk of water damage from bursting water pipes in addition to mold.

As a guideline for humidity, the risk of mold increases sharply at more than 60 percent permanent humidity. Correct heating in combination with correct ventilation can prevent this.

Heating on – depending on building type and age

The outside temperature from which you should heat depends on the age and construction of the house. You can use this breakdown as a rough guide:

  • Building built before 1977: Heating on when the outside temperature is 15 to 17 degrees Celsius
  • 1977 to 1995: 14 to 16 degrees Celsius
  • after 1995 (Construction according to the WSchV or Energy Saving Ordinance EnEV): 12 to 15 degrees Celsius
  • low-energy house: 11 to 14 degrees Celsius
  • passive house: 9 to 11 degrees Celsius

From the list you can see that the outside temperatures at which you should turn on the heating fluctuate greatly. While the radiators in old houses should be turned on as early as mid-September, residents of passive houses can wait a little longer before heating on a large scale.

Heating in autumn and winter: how warm should it be in which room?

Decisive for the answer to the question “When do you start heating?” is of course also your own feeling of heat. It is recommended that the indoor temperature should be between 20 and 22 degrees Celsius. Depending on the activity, whether you are sitting and working on the PC or whether you are moving and cooking, for example, the feeling is different and requires different amounts of heating.

Experts also advise different temperatures depending on the purpose of a room. A temperature of 16 to 18 degrees is sufficient in a bedroom, as well as in the hallway, where you spend very little time. A room that is too warm is not conducive to a good night’s sleep. It looks different in children’s rooms. Very small children in particular should not sit in cold rooms all the time – a temperature of between 22 and 24 degrees is recommended here and in bathrooms. In living and working areas as well as in the kitchen, the values ​​already mentioned are between 20 and 22 degrees.

Roughly one can say: The question of whether you turn on the heating is based on the energy status of the building and the desired interior temperatures.

More about heating:

Leave a Comment