Posted by Bud...Suncoast Plumbing Inc. on March 27, 1999 at 17:22:33:
In Reply to: Use Single 'Y' Flue Pipe for Venting Gas Boiler&H20 Heater posted by Ken Abrahamsen on March 26, 1999 at 23:56:28:
Ken:--Allow for combustion air cosiderations, most codes require 1 sq. inch off free air for each 1,000 Btus on the rating plate of the water heater or boiler. The same rule of thumb is generally used for ventilation. If the installation is in a small room, Louvers can be installed in the upper and lower sections of the door to meet these requirements.
If the Dryer is to be vented to the outside, some provision for make-up air will be needed so that there will be no negative air pressure to draw vent gasses back into the room...Bud..