Scout wrote:

the original unit is a $90 window shaker from Walmart. I
installed the pressure access ports after I removed the condensing coil. I
had to braze the refrigerant line into my tube-in-tube, and I needed a way
to purge with nitrogen while brazing, and then attach vacuum pump, and
finally, charge the unit. So I had refrigeration gauges on the system
during testing. I converted the pressures to saturated temps using the R-22
pressure temperature relationship charts. I also installed temperature
sensing wells at various points in the system, and inserted thermocouples in
them to get feedback.

Wow, that's a lot of work. What do you reckon your time is worth?


The superheat and subcooling values are calculated.

You have to know pressure & temp at two points in the system, and the total
weight of the charge.

After that you
can calculate anything. Without that, no calculation provides any useful data.
Usually output temp, weight of charge,
and watts are the only data.



The delta T I referred to is in/out of exchangers.
The delta T for 'baywater' vs cooling water is about 10 degrees.

Sounds like you are well above the average shade tree mechanic. Can you fix
turbine driven machinery? If so, please consider moving to NC... I want to hire
somebody to do my job so I can retire!

DSK

"DS King" wrote
Wow, that's a lot of work. What do you reckon your time is worth?
I'm a high school teacher (science and English). Long story how I got mixed
up with both areas.
Anyway, now I have nothing to do but play all summer. Besides, this was a
labor or love.

The superheat and subcooling values are calculated.
You have to know pressure & temp at two points in the system, and the
total
weight of the charge.
You are correct sir! But in this particular case, the total weight is
insignificant. I knew the saturated evap temp and the suction gas temp,
hence, I could calculate superheat of the suction gas. And I knew the
saturated condensing temp, and the liquid line temp, hence the sub-cooling
was simple subtraction. I didn't bother with superheat of the discharge gas
(got lazy toward the end).

Sounds like you are well above the average shade tree mechanic. Can you
fix
turbine driven machinery? If so, please consider moving to NC... I want to
hire
somebody to do my job so I can retire!
It's easy to see that you have a mechanical background too. I "retired"
into teaching after 23 years in mechanical construction and engineering.
Worked with boilers and industrial hvac equipment in Philadelphia and the
surrounding areas. I cannot, however, take your job! I'm licensed only to
MAKE steam in New Jersey and Philadelphia. My turbine experience is not
worth mentioning. I did spend two years stationed at a nuclear plant though
(Limerick), and did some work at Peach Bottom nuclear as well. All I know
is turbines are loud! Can't tell you much more than that.
Cheers,
Scout