ᐅ Definition of "Outside Temperature" — Average Over Several Days?

When configuring the heating system, the term "outside temperature" frequently appears. It is unlikely that this refers to the current temperature, which varies daily depending on the weather, but rather to an average over several days, right?

Can someone explain how the "outside temperature" is calculated?

It depends on the heating system.
And also on the value.
For Vaillant, for example, it can be the currently measured outside temperature or the 24-hour average. ;-)

And to make things even more complicated, most heating systems nowadays also offer the option to take the weather forecast into account 😉

For Nibe, the default setting is the average over 24 hours.

Do you mean the heating system design, specifically the standard outdoor temperature? The standard outdoor temperature is defined as the lowest temperature during a cold period that occurs at least 10 times within 20 years, lasting for at least two consecutive days each time.

Or are you referring to the temperature within the heating system (which you already have)? In that context, it’s important to distinguish whether it is the outdoor temperature at which the heating system turns on (sometimes called summer shutdown) or the outdoor temperature used for current control.

So, as others have mentioned, it could be an average value or the actual outdoor temperature. It’s not always straightforward.