Reg seems to breathe harder when looking up?

[meesier42]

Since there is a distance in a double hose setup from air source in mouth to reg on tank, does this cause more resistance in breathing than a single hose setup?

From the information that I have read about these double hose rigs is that they are tuned to have lower cracking pressures and therefore breathing them is compariable if not easier than single hose regulators.

The lower cracking pressure is normally a free flow problem for regulators is not nearly as much an issue since these double hose rigs will not be used as Octopus' for free flow should never be an issue

 

[Greg Barlow]

From the information that I have read about these double hose rigs is that they are tuned to have lower cracking pressures and therefore breathing them is compariable if not easier than single hose regulators.

The lower cracking pressure is normally a free flow problem for regulators is not nearly as much an issue since these double hose rigs will not be used as Octopus' for free flow should never be an issue

I collect, rebuild, and dive with vintage double hose regs. They have higher inhalation effort due to the pressure differential between the center of the lungs and the diaphragm. Using a backplate makes this differential even greater, so many divers use a simple harness to hold the tank and reg closer to the body. Due to the pressure difference, a double hose reg exhales easier than a single hose model.

The large diaphragm common to most double hose regs (like the DA AquaMaster), gives a mechanical advantage to the initial cracking effort.

Rolling over onto one's back causes the diver to have "chipmunk cheeks" from the water pressure differential.

The overall work-of-breathing effort for a double hose reg will not equal the higher performance single hose regs of today. I love my vintage regs, but understand their pros and cons.

Greg Barlow