Which uses more power? Heating recirculation or heating using external air.

[philip456]

Does anyone know which is the more power hungry when it comes to heating (not ac cooling).

Either having air flow set to recirculation or to take air in from the outside?

 

[Alb]

Recirc will use less energy but will cause fogging after a while.

 

[Lovemyev]

Using recirc will allow the car to reach the desired temperature more quickly, so in that case the answer should clearly be yes !.
But as @Alb correctly points out, the car will tend to mist up quickly !.
So switch over from recirc to outside air flow ASAP when you see misting starting.

 

[MoDolph]

How about only heating with fresh air vs. recirculate with AC on?

 

[Tim Green]

You are then using two battery drains, the heating and the aircon.
All the various possibilities have their uses, when appropriate.
For rapid demisting for instance, using both is justified, if you're not conserving the battery.
Horses for courses.

 

[Cocijo]

Doesn’t remote heating default to recirculating the air? It would make sense if it’s more efficient.

 

[MoDolph]

You are then using two battery drains, the heating and the aircon.
All the various possibilities have their uses, when appropriate.
For rapid demisting for instance, using both is justified, if you're not conserving the battery.
Horses for courses.

Yep but it's whether the decreased energy required to heat the already warm air is enough to offset the extra required to cool and reheat it after the AC.