- Mar 15, 2006
- Boat Info
- 1998 400 DB
- 7.4 Mercrusier Horizons
Thank you for your valuable input. I plan on disconnecting that duct this coming week to determine if there is a kink or some type of blockage.I did learn a LOT about ducting from this experience. I will now gone into the master stateroom and reconnect the ducts for better airflow. My ducts on my main unit were kinked and compromised airflow significantly.
Just in case anyone is wondering, The outlet from the 16K btu unit in the main salon has a 6 inch supply feeding a 7 inch duct and a 3 inch duct. There is a square box with 2 outlets on the original factory unit. I added a Y fitting on my new unit and then stepped one side up and the other side down. The hoses after years need reinforced and I get an enormous volume of air now flowing from both vents. The 3 inch duct is the supply on the starboard side below my cabinet and the 7 inch goes to the vent on the shelf behind the folding salon sofa bed.
IF I were you randerson I would take the duct off the side that is going to the guest stateroom and see if it is crimped or kinked leaving the unit. Especially since you said the air increases if you partially close off the flow in the master. There is an inner duct you can't feel unless you disconnect it. The insulation surrounding it made the pathway impossible to check without disconnecting. (sorry for the long ramble all)