Psychrometric charts, below sea level

[jreng1]

Does anyone know where I can find Psychrometric charts for below sea level, down to 5000 ft.

 

[MintJulep]

If such things exist I would guess that the Navy would be the place to look.

Otherwise, resort to the formulas.

 

[pennpoint]

jreng1
What is it you want to find out.

pennpoint

 

[jreng1]

pennpoint,

I am working on an underground mining project and require Enthalpy values for air at 5000 ft underground.

jreng1

 

[MintJulep]

I think any of the psychrometric calculators available could do this. Just enter -5000 ft as the altitude.

One option is here:

http://pmilligan.net/pmtherm.htm

I have no affiliation with that that, other than I use it. There are others available, a Google search should quickly turn up several.

Or, as I had previously suggested, crank out the formulas yourself.

 

[ProfSporlan]

My humble java psych calculator will properly handle "negative" altitudes within reason:

http://members.socket.net/~aschoen/psychcalc.html.

Unfortunately with PMTHERM, altitude is selected from a combo box, and -1000 ft is the lowest value accepted. The psychrometric equations behind PMTHERM would have accepted lower values though. But Paul and I didn't think anyone would need them. I did the psychrometric calculation programming for PMTHERM.

 

[MintJulep]

Prof,

in PMTherm -1000 is the lowest value available on the pull-down, but the combo box is not restricted to only values in the list. You can type in what ever you want.

 

[ProfSporlan]

MintJulep, you are correct. Paul Milligan wrote the interface, and I do see where he allowed user input for altitude.