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How Do You Guys Charge A System

 
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Old 07-12-2011, 07:50 PM   #1
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How Do You Guys Charge A System


hey guys. Just seeing how you guys charge an ac system lets say a 16 seer r-22 system. Reason why i ask is that i went to school for ac but never went into the trade (stayed in the plumbing and heating side of it) i had a customer who had a problem with there ac unit so had a friend come over to fix it ( i knew what the problem was but i dont have the equiptment to evac the system) anyway when i was in school they though us how to charge a system using superheat. When i asked him about it he laughed and said he goes by his gauges (was a 10 seer so he went by 30+ degrees above amibent on the high side) So how do you guys charge a system
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Old 07-12-2011, 08:59 PM   #2
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Re: How Do You Guys Charge A System


It depends on what the metering device is. If it's a txv, I go by sub-cool, if a metering device, super heat. If the literature isn't available, I go ten degree sub cool or super heat.

I do have a clamp on probe and like to keep the suction temp at about 55.

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Old 07-14-2011, 04:58 AM   #3
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Re: How Do You Guys Charge A System


Super heat and sub cooling. I check both weather its a fixed metering device or a TXV. SH more important on fixed metering devices, SC more important on TXVs.

Charging by 30 over ambient is a great way to over charge a unit when it has a restriction in the circuit.
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Old 07-14-2011, 09:31 PM   #4
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Re: How Do You Guys Charge A System


Quote:
Originally Posted by beenthere
Super heat and sub cooling. I check both weather its a fixed metering device or a TXV. SH more important on fixed metering devices, SC more important on TXVs.

Charging by 30 over ambient is a great way to over charge a unit when it has a restriction in the circuit.
Ditto
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Old 07-15-2011, 07:07 AM   #5
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Re: How Do You Guys Charge A System


First and always measure air flow. If the air flow isn't correct the charge will not be correct.

Subcooling method for txv system

Superheat method for flow restrictor system
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Old 07-31-2011, 09:52 PM   #6
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Re: How Do You Guys Charge A System


I charge based on the how much can you afford method then add 30 degrees supper sub-cooling txv divided by cfm over hvac delta tee.

actually I have a simple fool proof system for charging

1 clean condenser coil
2 check air flow
3 after condenser is dry use ether supper heat (fixed ) or sub-cooling (txv)
4 take an amp draw of the compressor
5 check for a 20 degree DT supply to return
Simple

Years ago I would look for a 60 to 70 pound back and a 225 to 275 head. but then years ago I sucked at this.
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Old 07-31-2011, 09:56 PM   #7
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Re: How Do You Guys Charge A System


Is supper heat, anything like super heat?

LOL...

I hate when I make typos.
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Old 08-02-2011, 06:34 PM   #8
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Re: How Do You Guys Charge A System


no supper heat is far more filling and tasty. Which is why I prefer it.

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