A BTO (branch take off) is commonly used in exhaust or ventilation applications where the ducting is needed to branch off in different directions. The reason for this may be an inline exhaust fan with multiple inlet points, a heat transfer system that disperses heat to different rooms or any other setup that will require ducting to be split.
Please Note: This image is generic – the actual shape of the junction may not always be exactly as pictured.
David Bogle –
Easy install quality products not the cheap stuff.now I can get on to the other jobs around the house and not worrry about condensation in the house.