What's causing this?

[SirGalahad]

There is damp, condensation forming on the outside wall around an air vent that sits under the kitchen. The kitchen floor is above the air vent and the vent is accessible via a hatch in the cellar. The sink is directly above that.

View attachment 293580View attachment 293581

 

[SirGalahad]

 

[Wayners]

Warm moist air hitting cold surface. This forms condensation

 

[SirGalahad]

So the radiator in the cellar not helping then? Would turning that down make a difference?

 

[Wayners]

In Germany if you rent a house you have to agree to open windows and doors for 30mins every day.
Air the House.
This replaces the moisture in air with fresh dry air from outside.
Another option is to have vents either side to get through draft.
You can also run a dehumidifier. This takes the moisture at the air.

No idea what will work for you but read up or watch YouTube for ideas.

I will open my windows for 10mins after tea to reduce moisture in the air. Help stop the windows running in water in the mornings. Condensation isn't so bad Vs not doing that