Originally Posted by Umpledord
I have a 2015 cougar 26 rbiwe trailer. It seemed like I wasn't getting much flow out of the heater vent in the kitchen area. So after trying to dump the black water and the handle pulled off in my hand I decided to remove the undercarriage cover and have a look around. (Black water handle problem for a different time). It seem that the manufacturer crammed two 4 inch hoses through a 6 inch square in the floor. One hose is almost completely squashed flat. It doesn't look like I can cut the hole any bigger. Does anyone know of a work around for this problem?
I haven't dealt with this, but doing the math there is enough area in a six inch square hole (36 square inches) to accommodate the area of two four inch circles (24+ square inches, 2x(3.14x4), the problem is the shape. The circumference of the ducts is about 12". Fabricate two square ducts 3"x3" from light gauge aluminum or even plastic, about 4"-6" long so you have room to work on either side of the hole. Cut the existing ducts at the hole and slide the new ducts through the hole and attach the existing ducts to the ends. The existing ducts will be a little big, but you can seal them together with aluminum foil tape. There will be a 25% restriction on air flow, 9 square inches instead of 12+ square inches, but at least it will be more even. Alternatively you could make the new ducts 3"x4" to give you the full 12 square inches of flow and split the existing ducts to fit around them and seal the resulting v shaped gap with aluminum foil tape when you connect them to the new ducts. Good luck.