Smallest possible window for ventilation in utility room

Good morning!

We are busily continuing with the planning. Our utility room will be relatively small (which is fine, not much needs to go in there). However, we plan to install a door leading outside so that later on you can get directly from the garage or carport into the utility room. Then you can leave jackets, groceries, dirty shoes there and not carry everything into the hallway. The problem now is that the door could only go where there is currently a window. A utility room without a window would be inconvenient because the washing machine, dryer, and air-to-water heat pump will be located there. Ventilation is therefore actually a must.
Our thoughts on how to solve the problem are as follows:
Either install the world’s smallest window. Or is there the possibility of installing ventilation only for this one room? What would be more cost-effective? Or do you have another idea?

Have a nice second Advent!

I would install a strip of light somewhere.

Mini-window is rubbish. There is also both in one, try searching the web for "door with tilt-and-turn window"

I am not entirely clear on what you need. Do you want a ventilation option for the damp shoes or an air supply for the heat pump? The heat pump needs more than just a window; there should be two holes in the wall, preferably around the corner so that the supply and exhaust air do not mix. For room ventilation, there are these elements for decentralized ventilation systems that alternately blow air in and out using a propeller.

Apart from the fact that there are doors with window cutouts (the best known is probably the patio door, which also comes with a lock), the statements "relatively small" and "leaving groceries and dirty shoes" do contradict each other

Utility room will be relatively small

to later be able to get directly from the garage or carport into the utility room. Then you can leave your jacket, groceries, and dirty shoes there and don’t have to carry all that into the hallway.

How is that supposed to be understood? The hallway then no longer serves its purpose, instead the utility room has to take the hit, which, when laundry days come, is already bursting at the seams anyway? Should the laundry then be dried in the hallway? I think you imagine a small utility room to be a little too "flexible" ;)

Install a decentralized ventilation system.