4 in. Round Tee

A:  You can get a 4" cap for the unused end and then seal that if you like. You can also stuff the unused end on the inside with insulation to prevent an accumulation of lint in that end. If this elbow will remain accessible to be able to reach in and clean out periodically, e.g. annually, then sealing the joints would be optional. The elbow you were speaking of has overlapping joints and would not leak. Buy mylar tape made for hot air vent systems. Foil tape breaks down in time and is also easily torn.

A:  You should not use tees in a dryer vent applications.

A:  Correct, you will need to crimp the desired portion(s) of the Tee. If you have any other inquiries about our Master Flow products please email warrantyllbp@gaf.com .

A:  No. Code says everything needs its own dedicated vent.

A:  It is possible, if both fans have a damper, check to see if your local codes permit it. If you have any other inquiries about our Master Flow products please email warrantyllbp@gaf.com .

A:  You can combine two or more ventilation systems into single exhaust port. considering air flow dynamics I would use a "Y" duct connecter rather than a "T" connector for joining two ventilation systems. Typical household exhaust fans come with 3" and 4" vents with dampers but for a junction you should add inline backdraft damper for each exhaust system at the junction and one more before the exterior exhaust port. Consider the length of the exhaust vent and exhaust fan CFM. When venting over 8', adapt to a 4" vent pipe at the fan exhaust port from a 3" exhaust port and adapt to 6" from a 4" exhaust port.

A:  Both fans will need backdraft dampers and the shared vent pipe to the outside of the structure will need to be oversized.

A:  Yes, there are closed 4" caps.

A:  You could, if needed. Look for Model# DC4 to cap one end it may need to be crimped to fit securely. If you have any other inquiries about our Master Flow products please email warrantyllbp@gaf.com .