One or two ducts to center vent?

[dmjlambert]

In the LMC catalog there is an option for buying plugs to replace one of the hoses to the A/C center vent (plugs are item 16). And in the Brothers catalog they have a special adapter for the center vent that only has a fitting for one hose, and they are claiming on their website and in a video that output of the center vent is increased by 40% by using their one-hose adapter because when using 2 hoses there is a canceling effect. They are saying "A similar modification was illustrated by GM back in 1972 to fix the problem of poor center vent volume." Does anybody have any experience with this one-hose-to-the-center-vent idea vs. the factory design?

[Andy4639]

Originally Posted by dmjlambert

In the LMC catalog there is an option for buying plugs to replace one of the hoses to the A/C center vent (plugs are item 16). And in the Brothers catalog they have a special adapter for the center vent that only has a fitting for one hose, and they are claiming on their website and in a video that output of the center vent is increased by 40% by using their one-hose adapter because when using 2 hoses their is a canceling effect. They are saying "A similar modification was illustrated by GM back in 1972 to fix the problem of poor center vent volume." Does anybody have any experience with this one-hose-to-the-center-vent idea vs. the factory design?

I plugged off the drivers side for 2 reasons. 1 the speakers I use in the center grill made it impossible to get the hose there. 2 I read the article about plugging one side off. To be honest I can't tell you if it did anything are not for the flow.

[davepl]

I disagree that going from two hoses to one would increase the flow. They still, in theory, should carry more air than a single pipe, even though limited and constricted at the end by the same outlet.

But two might be largely redundant. GM likely went to 1 because they found it did almost as good a job and saved money and simplified routing.

[Jrainman]

the static presure or the air would increase by going with a single duct, but you will loose CFM ,(Cubic ft per min ) because you are transitioning the air flow in to a smaller area.

What i am trying to say is ....its like turning your water hose on and then puting your finger over half the outlet of the hose..........

[Jrainman]

The only real way to upgrade your HVAC system would be to increase the size of your entire HVAC system .. including hot water coil, evap coil and compressor and also fan size and all ductiong and outlets.

Although I only have a heating system in my truck that I use every single day ,I have not had any issue as far as the ability of the stock system to heat or defrost the cab at all ,

[dmjlambert]

Originally Posted by Jrainman

The only real way to upgrade your HVAC system would be to increase the size of your entire HVAC system

Yes, that makes sense. I think the system will be adequate, not looking to upgrade, but wondering why the interest in "adapting" center vents to a single duct.

The ultimate for my Texas truck would be to run one duct to the center vent, and run the other duct on top of the hump (or through a console) to under the seat, then up into the bench seat and into a network of permeable material just under cloth upholstery in the driver's seat and seat back. A seat cooler.

[RenoKeene]

The system was designed to blow from both sides so it came out of the duct evenly in a cross pattern. I blocked the driverside so it blows at me in the driver's seat.

[100%Chevy]

I also blocked the drivers side of the center vent.
I'm greedy and wanted all the air on me!
Mike.