charging

[bbdd1]

I work mainly on light commercial a/c and heat pumps.
I would like to know, besides weighting in your freon
what method do ya'll like to charge by,pt chart,
superheat,subcooling,ambient plus 30,25 or 20 or some other method, just wondering what most tech's like.

[frigetater]

superheat or subcooling...depending on the type of metering device...use manufacturers recommendation

[john dalton]

Dear Bbdd1,

Regarding your previous post:

First and foremost, welcome to this forum of your peers, and colleagues friend. Please state your field experience and knowledge in the HVAC industry so we may better answer your posted questions more thoroughly. Until then, here’s some information to ponder:

The word “Freon” refers to the trade name “refrigerant” owned by Dupont for their discovery, and marketing of Freon gas, and although is used loosely throughout the end-users of this world, should be abandoned by professionals (you), and the word “refrigerant” substituted instead.

Next, as for the “other” methods of charging a system rather than weighting in a charge (requires a system be completely recovered, and evacuated), here are some answers.

First of all the “ambient plus 30,25 or 20 method” is a “generic round-a-bout ball park type” method, and should only be used by “generic round-a-bout ball park type service technicians”. So friend, do you want to be known as one of these type service technicians? (hint: this is a rhetorical question).

As Frigetater stated before me, the superheat/subcooling method is by far the best method for proper “refrigerant” charging my friend. If you have any questions regarding obtaining, or interpreting these readings please post further. We are here to help friend.

Lastly, although the superheat/subcooling method for refrigerant charge may not be the method that all service technicians employ, it is the most accurate one, period!

Good hunting friend………………

Respectfully Submitted,
John J. Dalton

[NormChris]

http://www.hvac-talk.com/vbb/showthread.php?threadid=33829

[john dalton]

Dear NormChris,

You’re quicker on the draw than I was on this thread my friend. Yours was the link I would have posted, had our young apprentice asked for help with either subcooling, or superheat. See you on the next thread, and I’ll try to be a little quicker on the draw, as to make this forum a bit more exciting my friend.

"Most" Respectfully Submitted,
John J. Dalton

[airworx]

subcooling and superheat is the only correct way to charge.
20-25-30 degrees above ambient doesnt work unless you like to sell compressors. pressures dont mean anything.

[bbdd1]

Hey friends, been in the business just 15 years,the first 10
i just grabed the suction line until cold.The reason i asked
is because i work mostly on commercial split units that the
average age is 10 yaers old.Now i want to charge my a/c's
as best as i can,thanks for the info.

[john dalton]

Dear Airworx,

Not wanting to split hairs, but……………………

Regarding your previous post:

“…subcooling and superheat is the only correct way to charge…”

The above statement is not entirely true my friend. There are other “correct” ways to charge a system depending on the type of system you have, here are only two examples, but there are others:

Packaged system: A weighted in charge is completely appropriate and correct.

Cascade system: Either a weighted, or static charge on the 2nd and above stages are correct.

Respectfully Submitted,
John J. Dalton

[john dalton]

Dear Bbdd1,

Refreshing to see someone who has been in the business for as long as you have, and still willing to stand up and say that you have a great deal more to discover about our profession. I’ll just silently stand behind you in that line my friend, thirty-one years in the business and still discovering new things every day.

Respectfully Submitted,
John J. Dalton

[Shophound]

Originally posted by john dalton
Dear Airworx,

Not wanting to split hairs, but……………………

Regarding your previous post:

“…subcooling and superheat is the only correct way to charge…”

The above statement is not entirely true my friend. There are other “correct” ways to charge a system depending on the type of system you have, here are only two examples, but there are others:

Packaged system: A weighted in charge is completely appropriate and correct.

Cascade system: Either a weighted, or static charge on the 2nd and above stages are correct.

Respectfully Submitted,
John J. Dalton


Dear Mr. Dalton,

Excluding cascade systems (I believe the subject matter is commercial split system HVAC), and with no intention as to appear to be straining at gnats with you, I would wish to add that even with a package unit and weighing in the charge, I wouldn't be satisfied with that alone to conclude that the charge was correct.

Weigh in the charge, gather the superheat and subcooling readings and any other pertinent parameters (yes, including pressures)...then call it good.

To the other comment (not made by you) regarding pressures not meaning anything, again at the risk of being the nit-picker (and I do know what you mean by the statement), pressures DO mean something. They mean something alone, they mean a whole lot more with other parameters factored in.

Most respectfully submitted,

Shophound, back online after a four day hiatus