Charging walk in coolers and freezers

[crackertech]

I always charge liquid into the suction line and have yet to kill a compressor although I have tried to in a pi$$ed off mood.

[jpsmith1cm]

I always charge liquid into the suction line and have yet to kill a compressor although I have tried to in a pi$$ed off mood.

3/8" hose to the suction service valve.

You just weren't trying hard enough...

[crackertech]

3/8" hose to the suction service valve.

You just weren't trying hard enough...

Gee thanks I'll try to remember that.LOL

[rayr]

3/8" hose to the suction service valve.

You just weren't trying hard enough...

LMAO That is a GREAT TECH TIP!!!!!!!!!!

[jpsmith1cm]

LMAO That is a GREAT TECH TIP!!!!!!!!!!

Always trying to be helpful.

If you frontseat the valve, the refrigerant will charge faster due to a greater differential in pressure.




For all the newbies out there, I should post a disclaimer.

Do not try this at home or on the job. I am a professionally trained idiot.

[Poodle Head Mikey]

Install a schrader access tee under the TXV equalizing line flare nut. Then blow liquid in there with the system running. The evap will boil it off and the low SSH will throttle the TXV.

You can also pump 90-95% of the charge into the high side with your recycle machine before starting the compressor. Then just top off to 10 degrees subcooling and you're done.

PHM
--------

Hi,

I worked with a tech recently who when charging walk in coolers and freezers after compressor change outs. He would cut off the condenser fans for brief periods of time. Both R-22 and 404-A.

Im just curious at what this was accomplishing and do any of you guys also do this and why? And how is this done properly etc...

Another thing say you are charging an R22 refrigeration system (large pan cooler) which requires 34 pounds of R-22. I had a heck of a time getting that much charged in. I ran warm water over the container many times to get the pressure back up to charge in the vapor.

Any tricks out there at speeding this process up? I know that charging liquid is considered a no no and the little liquid charge restrictor device is pretty slow as well.


Thanks

[timebuilder]

Install a schrader access tee under the TXV equalizing line flare nut. Then blow liquid in there with the system running. The evap will boil it off and the low SSH will throttle the TXV.

You can also pump 90-95% of the charge into the high side with your recycle machine before starting the compressor. Then just top off to 10 degrees subcooling and you're done.

PHM
--------

I always enjoy hearing ideas. Thanks, PHM!

[frigeguy]

Always trying to be helpful.

If you frontseat the valve, the refrigerant will charge faster due to a greater differential in pressure.




For all the newbies out there, I should post a disclaimer.

Do not try this at home or on the job. I am a professionally trained idiot.

LOL I had to quote this one...but it was a good laugh

[Poodle Head Mikey]

I promise that you Will hear some ideas! <g>

PHM
---------

I always enjoy hearing ideas. Thanks, PHM!

[Airmechanical]

I always charge liquid into the suction line and have yet to kill a compressor although I have tried to in a pi$$ed off mood.

x1000



.

[hvacr man]

I dont do a lot of refrigeration but on a smaller walk in I will calculate how much liquid the cond coil will hold and then the receiver. I add 80% of what the receiver will hold and what the cond coil will hold. I have done this 3 times and havent had a problem with being short in the winter or overcharged in the summer.

[AtoZhvac]

I dont do a lot of refrigeration but on a smaller walk in I will calculate how much liquid the cond coil will hold and then the receiver. I add 80% of what the receiver will hold and what the cond coil will hold. I have done this 3 times and havent had a problem with being short in the winter or overcharged in the summer.

Hi

Please tell me how you calculate how much refrigerant to put into the condenser and the receiver.

Something that really bothers me about the Sporlan Head Master charging data is nothing is considered for the evaporator or the line set. Am I wrong that that does not matter when making a proper charge?

Thanks

ps please some of you guys lay off of turning this thread into a joke fest!
I am sincerley trying to learn something important here and I honestly can not tell when some of you are contributing something useful or joking about something.



Thanks

[jpsmith1cm]

Hi


Something that really bothers me about the Sporlan Head Master charging data is nothing is considered for the evaporator or the line set. Am I wrong that that does not matter when making a proper charge?

Yes. I cracked a few jokes, but now I get to be a jerk.

Did you read the Sporlan instructions? Really?

If so, you would know that the first step is to charge the system to a clear sightglass.

This automatically accounts for linesets and evap and all that.

If you're going to learn something, make it the right thing.

[jpsmith1cm]

Hi

Please tell me how you calculate how much refrigerant to put into the condenser and the receiver.

Something that really bothers me about the Sporlan Head Master charging data is nothing is considered for the evaporator or the line set. Am I wrong that that does not matter when making a proper charge?

Thanks

ps please some of you guys lay off of turning this thread into a joke fest!
I am sincerley trying to learn something important here and I honestly can not tell when some of you are contributing something useful or joking about something.



Thanks

Something bothers me about this reply.

The sporlan method allows you to calculate the amount of refrigerant required to flood the condenser at low ambient conditions.

The receiver does not enter into these calculations except that it must be large enough to hold that excess when it isn't needed.

I don't understand how low ambient is going to affect the amount of refrigerant held in the evap or the lineset, nor do I see how the semi-scientific WAG method offered compensates for them anyway.

If you want more calculations, look up the Heatcraft installation manual. It has all the numbers to calculate the entrained charge very, very closely. If you are having trouble with the math, bring the numbers here and we will help you with it.

We DO joke and fool around, but there is more than a little knowledge and experience hanging around here.

[AtoZhvac]

Yes. I cracked a few jokes, but now I get to be a jerk.

Did you read the Sporlan instructions? Really?

If so, you would know that the first step is to charge the system to a clear sightglass.

This automatically accounts for linesets and evap and all that.

If you're going to learn something, make it the right thing.

jpsmith1cm,

Yes indeed I "REALLY" read the Sporlan instructions. You seem to have missed the fact that my post that you quoted was my reply to a post that was made by hvacr man who says he calculates how much the cond coil will hold AND the receiver. See the quote below please.

posted by hvacr man :
"I dont do a lot of refrigeration but on a smaller walk in I will calculate how much liquid the cond coil will hold and then the receiver. I add 80% of what the receiver will hold and what the cond coil will hold. I have done this 3 times and havent had a problem with being short in the winter or overcharged in the summer."

So yes jpsmith1cm I certainly wanted to know what procedure that "hvacr man" uses to calculate for the cond coil and the receiver!
As far as I know it could be as good or even better method than the Sporlan instructions.

Also please forgive me for assuming that if the condenser tubing and bends can be calculated for charging purposes that similar measurements and calculations might also apply as well to the evaporator and the lineset.

After all I have seen systems with NO sight glass on them.

Im not going to take the route of being a jerk,sarcastic,or condescending on this forum to another member and I would encourage everyone to do the same.

I continue to believe that this thread will be helpful not only to me but potentially to others as well.

Best Regards

[hvacr man]

atozhvac
I am not sure that the way I have done it is correct, but it netted the results I needed. I really expected some yeahs or neys to my method. I do know that this cant be used for all systems. I have looked for the info on the receivers on the net but cant find it. I do have a hard copy so all I can do is give you an example, but you should be able to locate it on the net or call a refrigeration supply house. So anyway I calculate the cond tubes and u bends just like the sporlan instructions then I measure the reciever and refer to the chart that I only have a hard copy of. Example from the chart: A 6inch dia. x 12long vertical reciever will hold 10lbs of r-22 @ 90 degrees and 90%full. We get hotter here than that some times so I figure a little less. I would then add that to the number I came up with on the sporlan chart for the cond volume and put that total into the system. I am NOT saying that this is the way to do it, but 2 of the 3 or 4 times I have done this I cross checked with the full formula from sporlan and they came out very very close.

[AtoZhvac]

atozhvac
I am not sure that the way I have done it is correct, but it netted the results I needed. I really expected some yeahs or neys to my method. I do know that this cant be used for all systems. I have looked for the info on the receivers on the net but cant find it. I do have a hard copy so all I can do is give you an example, but you should be able to locate it on the net or call a refrigeration supply house. So anyway I calculate the cond tubes and u bends just like the sporlan instructions then I measure the reciever and refer to the chart that I only have a hard copy of. Example from the chart: A 6inch dia. x 12long vertical reciever will hold 10lbs of r-22 @ 90 degrees and 90%full. We get hotter here than that some times so I figure a little less. I would then add that to the number I came up with on the sporlan chart for the cond volume and put that total into the system. I am NOT saying that this is the way to do it, but 2 of the 3 or 4 times I have done this I cross checked with the full formula from sporlan and they came out very very close.

Hi

Thanks for the reply!
Does your chart have an address or info on it that could lead me to where to get one? Could you email a copy of it to me? if so please email to <Please put your email address in your profile, not in post, thank you>


Thanks

[jpsmith1cm]

jpsmith1cm,

Yes indeed I "REALLY" read the Sporlan instructions. You seem to have missed the fact that my post that you quoted was my reply to a post that was made by hvacr man who says he calculates how much the cond coil will hold AND the receiver. See the quote below please.

posted by hvacr man :
"I dont do a lot of refrigeration but on a smaller walk in I will calculate how much liquid the cond coil will hold and then the receiver. I add 80% of what the receiver will hold and what the cond coil will hold. I have done this 3 times and havent had a problem with being short in the winter or overcharged in the summer."

So yes jpsmith1cm I certainly wanted to know what procedure that "hvacr man" uses to calculate for the cond coil and the receiver! As far as I know it could be as good or even better method than the Sporlan instructions
.

Also please forgive me for assuming that if the condenser tubing and bends can be calculated for charging purposes that similar measurements and calculations might also apply as well to the evaporator and the lineset.

After all I have seen systems with NO sight glass on them.

Im not going to take the route of being a jerk,sarcastic,or condescending on this forum to another member and I would encourage everyone to do the same.

I continue to believe that this thread will be helpful not only to me but potentially to others as well.

Best Regards

Point #1. Refrigeration is 95% of what I do. I work on stuff that hold 7 ounces of gas and I work on stuff that holds 1700# of gas and everything in between. I've done it wrong and I've done it right. I have learned the hard way what works and what doesn't.

Point #2. Somehow I seriously doubt this.

Point #3. Systems without sightglasses are typically critically charged systems with a weighed in charge and not pertinent to this discussion.


I have tried to help you. You have refused to accept the advice that has been given you. There is a right way and a wrong way to do things. You can accept the advice of someone who admits to not doing a lot of refrigeration work, or you can take the advice of the people who design the equipment that you are working on.

Your call.

[jpsmith1cm]

Hi

Thanks for the reply!
Does your chart have an address or info on it that could lead me to where to get one? Could you email a copy of it to me? if so please email to

Thanks

Probably the same chart I offered you a while ago.

[crackertech]

Hi

Thanks for the reply!
Does your chart have an address or info on it that could lead me to where to get one? Could you email a copy of it to me? if so please email to

Thanks

please remove your E- mail addy