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When a technician is testing the charge level or subcooling or superheat, and is using gauges with hoses that are several feet long, how much Freon is lost from filling up the hoses? Should the technician have a canister of Freon with him to replace what is lost when he completes his system check? Thanks.
Professional Member*
If the hoses have low loss fittings like most of ours do, the loss is minimal and would take several thousand "checks" before affecting performance.
"Surprised ?! If I woke up tomorrow with my head sewn to the carpet, I wouldn't be more surprised."
Clark Griswold
Professional Member
With low loss fittings and proper techniques you won't lose enough to make a difference with regular service. Should they put more in just because they hooked up? No. The amount you are talking about is not readily measurable, so all they would do is screw the charge up.
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God Speed, Jim. We'll miss you - 2-26-23
Should he have a jug of gas in the truck yes.
Should he try to put .25 oz. back in, no. ( presuming low lose fittings )
Professional Member
Be careful, many of the techs on this site and many in the field use one set of gauges for all residential refrigerant types. Which means they dump the charges on their gauges after each use. If your system is near critical and the tech has 6 foot hoses it could affect system performance.
I STARTED WITH NOTHING, AND I STILL HAVE MOST OF IT!
Former Site Administrator- Now Retired
Originally Posted by emoney1971
(cough)
Bull****
Please explain to this group what you mean by "critical charge" on a residential unit and how loosing less than on ounce of refrigerant will matter.
Professional Member
critical charge .....resi AC....... naahhhhhh
besides..... most resi guys do not dump the hose charge between calls, they deal primarily with just a few refrigerants and have a set for each.
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Professional Member*
I dump the charge from my hoses after every check. Matter of fact I disconnect from the high side of the equipment first, open the high side of the guage to the crossover and then slowly open the low side of the guage to the crossover. IE: I put what liquid I took out of the system right back in. The only thing thing left in my guage set when im done is whatever gas it'll hold at the pressure of the low side. Anyone ever measured how much that is? Oh........ I run 5' hoses if someone is going to do the measurement.
Use the biggest hammer you like, pounding a square peg into a round hole does not equal a proper fit.
Professional Member
diminimus
Professional Member
Yeah firecontrol.... I think every good tech does that.... I was just saying that you would not vent the hoses to atmosphere between calls.
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Professional Member
I pre-charge my gauge hose set before I hook them up.......
yeah,yeah, that's the ticket.
Actually I don't.
If everything was always done "by the book"....the book would never change.
Professional Member*
O God! how to folks get so bored? I wished I had time to worry about stuff like that,
heck with my busy life that would be like meditation to me.
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“Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
Professional Member*
A similar thought crossed my mind...O God! how to folks get so bored? I wished I had time to worry about stuff like that,
heck with my busy life that would be like meditation to me.
...interesting what questions get asked in this section at times.
Professional Member*
Hey good to see a Texan on the Educational Committee and folks think were are just good
old "dumb" country boys in Texas, I guess the "intelligent" owners here think differentially.
__________________________________________________ _______________________
“Experience is a hard teacher because she gives the test first, the lesson afterwards" ~ Vernon Law
"It's what you learn after you know it all that counts." ~ John Wooden
"When the teachers become unteachable we're all in trouble" ~ Mr. Bill
"Remember "Pro" is only a name, it's not always a mindset determined to do everything correctly" ~ Mr. Bill
Professional Member
Everything is bigger in Texas
Professional Member*
I use 4' hoses with a ball valve on the end, then another 10" hose screwed onto the ball valve. Each of my 3 hoses is a 3 piece assembly(long hose-ball valve-short hose). The short hoses with a ball valve permanently attached are not a good idea because you can't purge the air out of just the small hose if you keep pressure in your manifold like I do.
I can't stand low loss fittings!
When I disconnect from a system, I open both valves on my manifold briefly to clear any oil, and close the ball valve on the liquid side.
I let the system pull all the liquid out of my hoses and manifold, then close the ball valve on the vapor side and disconnect my hoses. I only loose the little bit of refrigerant in the 10" hoses.
This leaves my manifold and hoses under some pressure from the remaining vapor.
The next time I hook up to a system, I connect my hoses, purge the air out of the 10" hoses and open the ball valves.
I'm loosing less than an ounce of refrigerant from connecting and disconnecting to a system.
Before I got a 2nd set of digital gauges, I used the same set for R-22 and R-410A.
Before hooking up to a system with a different refrigerant than the last one I worked on, I would bleed my gauges and manifold down to 0psi, and hook up to the system, then purge my hoses and manifold with the new refrigerant. Still probably loosing less than an ounce of refrigerant.
Now that I have 2 digital manifolds, I just use one for each refrigerant.
Professional Member*
According to recent studies, even our bellies.Everything is bigger in Texas
God Speed, Jim. We'll miss you - 2-26-23
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