Wood stove external air supply - What is the best technique for it?

Ok, learned something new again :) But why did you forgo it? An [Außenluftanschluss] basically has no disadvantages, only advantages with hardly any additional costs.

But why did you do without it? An outside air connection basically has no disadvantages, only advantages with hardly any additional costs.

It has a very big advantage: The hot air goes out through the chimney, creating a negative pressure in the house.
As a result, cold air from outside is sucked into the house through all the cracks.
The only prerequisite is that the blower door value of the house is poor enough.
This pleasantly cools the living space while actually far too much heating energy is introduced into the living space through the chimney. :cool:

I quickly couldn't find how much air volume is required for the combustion of one kilogram of wood. Compared to the air volume in the room, this does not create any significant negative pressure, especially since in daily life a door or window is occasionally opened here and there. The whole thing is completely unproblematic. You save yourself additional dampers and the house.

The chimney also burns great, when starting to burn it makes sense to open a window for a few minutes.

Opening a window makes no difference at all for us during the burn - not even at the beginning. The only important thing is that the chimney draws properly. The tiled stove has a bypass damper for starting from a cold state in order to use the direct draft. This can be closed after a few minutes.

I did not quickly find how much air volume is needed for the combustion of one kilogram of wood.

One can find, for example, 80m³ of air for 1kg of wood. So, in a 20m² living room with a ceiling height of 2.5m, the air per kg of wood is exchanged 1.5 times completely. And of course it comes entirely from outside, where else would it? At the current outside temperatures, really (not) a great thing! ;)

Opening the window doesn't make any difference to the burn - not even at the start.

Yeah, then the house must be quite "drafty" even with closed windows. Probably no blower door test done?

Ok, learned something new again :) But why did you do without it? An outdoor air connection basically has no disadvantages, only advantages with hardly any additional cost.

The difference for us was at least the stove. Our chimney can also supply outdoor air. But we wanted a panoramic stove. This way we were able to buy a good used one for little money, otherwise we would have had to buy a new one for three to four times the price. And why should I do that? What disadvantages does the lack of an outdoor air connection have, and what advantages should the outdoor air connection have?

The difference for us was at least the stove. Our fireplace can also supply outside air. But we wanted a panoramic stove. That way we could buy a good used one for little money

Exactly the same for us and for our model an outside air module could also be purchased. As often mentioned: call the chimney sweep beforehand, their position on this is crucial!!!