Heat Transfer a Different Elevations

[Shooze]

When a heater is installed at a higher elevation than sea level does it take more or less gas to heat the bath

 

[Plasmech]

Not anywhere neat 100% sure I understand the question, but there is a post only a few clicks below this one about "Thermal conductivity of a vacuum", the main jist being that pressure does not affect thermal conductivity of a gas unless you get to extremely low levels, as in less than .01 Torr.



-Plasmech

Mechanical Engineer, Plastics Industry

 

[IRstuff]

The other half of the answer is that only the BOILING point is affected by pressure, so unless the intent is the consume the bather afterwards, the heating to a non-boiling temperature is the same, since you'd most likely do this in a water heater that's amply insulated.

TTFN

FAQ731-376

 

[Plasmech]

I wish this forum had an "edit" feature...ugh.

-Plasmech

Mechanical Engineer, Plastics Industry

 

[willard3]

The film coefficient will change with gas conductance/density which changes with elevation.

Higher elevations will require more gas to heat the bath because heat transfer is lower.

 

[djack77494]

I think willard's got it. Properties of the hot flue gases will change with pressure. Increasing elevation = decreasing pressure = changes making the heat transfer process less eficient.
Doug.