Why is the kitchen sink usually placed under a window.
Kitchen sink vent stack. Notice how the main vent and waste pipe remain separated behind the sink only connecting via the attached went pipe. Because the vent must extend horizontally from the drain and can t slope down with respect to the vent outlet there s literally no way to install a conventional vent in an island. It basically involves tapping into the existing drain trap configuration to install an aav via a new sanitary tee fitting and a short upward extension pipe. These in turn lead to the main stack which is the largest pipe of all typically 4 inches.
Because the main stack is also vertical it will rarely clog. What not to do with sink drain vent pipe plumbing nightmare gregvancom. If you were to look in most of the homes kitchens you d find a sink under the outside window. Sinks installed in kitchen islands present a problem when it comes to venting.
The plumbing vent. The plumbing code requires venting on every plumbing fixture in your house to keep your pipes from clogging and to protect. How to install a vent pipe for a kitchen sink that is under a window. When a kitchen island has a sink the vent has to go through the floor to connect to the vertical vent stack and to overcome the problem of the vent having a downward slope the code allows a structure called a loop vent.
It connects just above the trap and extends vertically. From the side angle it becomes easier to imagine what these pipes might look like behind your bathroom or kitchen walls. The general rule is that smaller drainpipes 1 1 4 inches for bathroom sinks and 1 1 2 inches for kitchen sinks for instance lead to larger branch drains. Small vent pipes can choke off on the inside with ice in bitterly cold climates.
The chicago loop is the answer. When you use a full sized 3 or 4 inch vent it takes much more ice to close off the vent pipe. Installing an aav to vent a sink is fairly easy whether you are replacing an old existing vent or putting one in for the first time.