razorback
Full Access Member
id settle for ac in the front seat...
Crew cab rear AC
- Thread starter RLDSL
- Start date
Ironman03R
Full Access Member
I just saw this thread, I wanted to do this after I saw an AC unit on Ebay out of a Centurian F150 about a year ago. Nice work!
So far I haven't found any references to time involved in getting water to boil in a vacuum, heck, the literature won't even tackle boiling time at room temp on a stove, too many variables, but even if there were, it would only be time to begin boiling in an open cylinder, standard scientific practice, an air conditioning system is far more complex, lots of twists and turns that would cause the escaping steam to want to condense and go back to square one, hence the industry standards for vacuuming times for open systems.
Below is a chart for the temps needed to boil at a specific vacuum. You will notice that the vacuum produced by many lower end pumps is not enough to boil water out of a system unless it is REAL lot outside A lot of lower end pumps have trouble reaching 28 and youll notice that it would haveto be 100 deg out for it to begin boiling at that vacuum, and just like a stove, the heat outside is going to play a big role in the time involved to boil it out
other nasty things come into effect if a system has been partially evacuated without fully getting it cleaned out, some really wierd stuff starts happening to the water that makes it even harder to get out, but lets stay out of physics 201 before I blow a brain gasket and have to self prescribe something in a brown bottle
*Since forum will not keep format, chart is chopped up but in each pair of numbers the top is the level of vacuum and the lower is the temperature at which water boils at that vacuum
The chart below shows how temperature plays a role in the level of vacuum needed to boil water.
Inches of Mercury
Boiling Point of Water °F
26.45
120
27.32
110
27.99
100
28.50
90
28.89
80
29.18
70
29.40
60
29.66
50
29.71
40
29.76
30
29.82
20
29.86
10
All values are at sea level. Subtract 1 inch for each 1000 ft. above sea level
Let me try to fix that for you
Inches of Mercury===============Boiling Point of Water °F
26.45========================120
27.32========================110
27.99========================100
28.50=========================90
28.89=========================80
29.18=========================70
29.40=========================60
29.66=========================50
29.71=========================40
29.76=========================30
29.82=========================20
29.86=========================10
All values are at sea level. Subtract 1 inch for each 1000 ft. above sea level
There you go, that should be a lot easier to understand.
Inches of Mercury===============Boiling Point of Water °F
26.45========================120
27.32========================110
27.99========================100
28.50=========================90
28.89=========================80
29.18=========================70
29.40=========================60
29.66=========================50
29.71=========================40
29.76=========================30
29.82=========================20
29.86=========================10
All values are at sea level. Subtract 1 inch for each 1000 ft. above sea level
There you go, that should be a lot easier to understand.
Last edited:
JwS
Full Access Member
Of course it depends on your environment, if you are in a 95% humidity part of the country you will have more stuff to remove. Here where the humidity is more like 10-20 percent there is less to get out.
Good note about the change with elevation, I could not figure out why I only saw 26 or 27 inches, double checked everything, scratched my head, then realized I am at 4000ft....hmmm
JwS
Good note about the change with elevation, I could not figure out why I only saw 26 or 27 inches, double checked everything, scratched my head, then realized I am at 4000ft....hmmm
JwS
