19

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: Drainage pipe is not sealed

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: enter image description here enter image description here

Thin pipe on the first photo on the left is a waste from dishwasher.

trailmax
  • 448
  • 1
  • 5
  • 15

6 Answers6

36

You don't have a trap seal, to prevent air from moving through the drain.

enter image description here

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...

enter image description here

Use a tailpiece like this, off the bottom of the sink.

enter image description here

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).

  1. Remove the sanitary tee connection from the drain.
  2. Connect the dishwasher outlet to the sanitary tee, where it used to connect to the drain.
  3. Connect the end of the trap (where the dishwasher used to connect), to the drain.

Basically, just swap these connections.

enter image description here

Tester101
  • 133,087
  • 80
  • 327
  • 617
5

You could put a cover over the drain box but when you do so it has to allow for free air flow so the isolation afforded by that air gap drain box still functions properly. If I was making the cover it would have a baffle design with a double wall construction. See figure below:

enter image description here

The inner wall of the baffle cover would sit on the ground or maybe even set below grade. The outer shell would not come all the way down. The picture is somewhat conceptual and does not attempt to show how the two parts of the cover fasten together.

Before committing to an elaborate construction project you could prototype the design to determine how effective the concept is. This could be done using heavy corrugated cardboard carton material. You easily cut the cardboard with a sharp utility knife and a straight edge. The pieces can then be joined together with hot melt glue. (Hot melt glue sticks to the brown corrugated cardboard amazingly well). Hold your prototype in place using some bricks to keep the howling wind from blowing it away.

Michael Karas
  • 67,833
  • 7
  • 68
  • 153
3

While I agree that this was assembled backwards I think the apparent lack of a vent is acceptable here. It looks like it basically goes through the wall and then into that box outside--so long as it's close enough to the sink that would suffice for venting.

Loren Pechtel
  • 982
  • 1
  • 7
  • 14
2

Most drains (in the US) vent thru a vertical pipe which prevents sewer gas from accumulating in the structure (home,apartment,etc) Part of that system should include a trap (usually a J or S shaped piece of pipe which holds a small quantity of water which prevent air or gasses from passing back into the room from the sink or toilet. If that trap was not included air ("wind") might be noticed.

Check for presense or lack of a trap.

M. Flood
  • 41
  • 3
1

All you need is a trap on both paths like the one you have coming from the dishwasher/washing machine

The trap fills with water and stops draughts although in excessively windy conditions its still possible for very strong winds to force their way through a water trap but normally there wont be enough pressure

I wouldn't personally suggest swapping the fittings over personally as theyre pretty cheap, so I would say its better to get a second trap or I bend and fit it between the sink and the outside pipe

removing it from the other pipe will make it more likely that food waste that goes down the plug hole could end up in the draining pipe from the appliance and risk causing a blockage if there isn't a filter, and even if there is a filter it could could clog the filter up

Mike Mckay
  • 11
  • 1
0

An easy test would be to cut a panel out of some junk styrofoam, that would go under the black grate, and block up but not tightly seal, the tub that the white pipes drop into. It's free and easy to work with, and if such a block cuts down on the wind problem, you can then make something more permanent and better looking.

Pete Danes
  • 109
  • 1