We live on a windy coast of North Sea. High wind is a norm here. One of the problems I face with the wind: it comes out from kitchen sink drainage pipe. If it is blowy outside, you can feel a draft coming from the drainage pipe.
I think the problem is because the drainage pipe finishes outside and does not make a sealed connection:
Because the drainage pipe is not sealed, the wind blows up the pipes and comes out from my sink drain. Making the kitchen colder (we have enough vents there already!)
Is there anything can be done to prevent this draft?
I'm thinking cover the drain hole (the one on the picture) with something, but could it not cause more problems?
UPD: Pipes under kitchen sink look like this:
Thin pipe on the first photo on the left is a waste from dishwasher.
Best Answer
You don't have a trap seal, to prevent air from moving through the drain.
Only the dishwasher is draining through the trap, so there's no trap to prevent air from coming up the drain. you'll have to fix the plumbing, so that both the sink and dishwasher use the trap.
Instead, the plumbing should look more like this...
Use a tailpiece like this, off the bottom of the sink.
This allows you to connect the dishwasher to the drain. You can trim the end of the tailpiece, so that it fits into the space you have.
Connect one side of the trap to the end of the new tailpiece, and the other end to the drain pipe.
You'll also have to add a vent to the system. Depending on where you live, air admittance valves (AAV) can be used.
After looking more at the plumbing, you might not need additional fittings (other than for venting).
Basically, just swap these connections.