Hydrogen
a. Windage losses are less. Hence efficiency increased.
b. Heat transfer is more. Hence output per volume is increased.
c. No corona discharge, which makes insulation life long.
d. Lesser denser and penetration and cooling more.
e. No fire risk at purity 4% to 74%
DM Water
a. Non-toxic and low viscosity.
b. High thermal conductivity.
c. Low conductivity.
d. Freedom from fire risk.
e. External heat exchanger used.