# Refrigerant Overcharge



## HVACWalter

OK, so now I get to display my lack of knowledge. I am here to learn so hopefully I can find some way to give back as well.

Can Refrigerant Overcharge cause icing?


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## gene2

I have seen systems 100%-200% overcharged, showing normal or freezing temps, they might have air in the system also & dirty coils or air filters that were not checked.

Best course of action is recover refrigerant, weigh in new charge AFTER cleaning coils & air filers. 

Amazing that compressors even withstand this.


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## Yuri

Overcharge can cause icing as the evaporator gets flooded with liquid refrigerant, not all of it boils off to a vapor and some can slug back to the compressor and wreck the valves.


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## beenthere

An over charge in its self won't cause freezing(of the coil).
There are usually other things at work that cause it to freeze because of the over charge.


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## hvaclover

The simple answer is yes. A fixed orifice system is more susceptible to icing than a TXV.


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## hvactech

Overcharging is the most common rookie mistake! And it's the worst thing you can do to a compressor. Most of the time it's caused by a plugged air filter or dirty evap coil.


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## scooter

hvacwalter
Why are you asking this question.
If you have a specific situation then please list all the info you can. 
Equip brand, year, size, lineset size, refrigerant, equip location ie. residential, commerical, crawl, basement, upflow, counterflow etc. 
Only then can we try to accurately find a solution to your problem. 
If you are just asking for general education then I am sure that we can help you with this, however, keep in mind that there are several factors involved with A/C and or refrigeration that can cause or create the illusion of overcharging. 
Taking the time to learn basic fundamentals will be well worth the time and money.
Please do not try to learn by takng the quick answer and running with it. Learn how to ACCURATELY DIAGNOSE the problem/s to determine proper service. 
Always start diagnosis by VERIFIYING THE COMPLAINT!!!! if you cannot verify the complaint, dont fix anything. there is nothing wrong with circling in a holding pattern. 
many times a 10 min interview which involves YOU actually listeneing to your customer will shorten hours of diagnosis.
Always verify the repair. sometimes this requires a call back or another visit, but it must be done.
Let us Know!!!
Scooter


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## hvaclover

Yeah, and don't forge the DNA sample too! LOL


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## gene2

The first rule is when confronting a problem, go back to the basics & think about it awhile. Unfortunately, this business is very scatter-brained in education & training because what we do is educated guesswork. I don't think we should be so hard on someone in the trade earnestly trying to learn or find a solution. In the heat of battle we all can end discombulated, tired at the end of the day. Suggestions regarding the basics to be posted are helpful though. We all were once rookies, actaually still are.


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## hvaclover

gene2 said:


> The first rule is when confronting a problem, go back to the basics & think about it awhile. Unfortunately, this business is very scatter-brained in education & training because what we do is educated guesswork. I don't think we should be so hard on someone in the trade earnestly trying to learn or find a solution. In the heat of battle we all can end discombulated, tired at the end of the day. Suggestions regarding the basics to be posted are helpful though. We all were once rookies, actaually still are.


i concur.


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## RoBoTeq

I've seen compressors encased in ice due to overcharged conditions.


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## nicktech

if the unit is grossly overcharged the evap pressure and boiling point would be higher than normal, this would get you further from freezing. however a slight overcharge could cause freezing if it's compounded with a low load situation (not enough air going over the coil). the overcharge usually is caused by not properly evaluating the unit and assuming low pressure meant low charge.


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## heatgain

I have never heard of an a/c system icing from an overcharge without other underlying conditions. Roboteq can you give some details on how these overcharged systems caused icing. I have only seen overcharged systems cause icing with refrigeration systems.


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## RoBoTeq

heatgain said:


> I have never heard of an a/c system icing from an overcharge without other underlying conditions. Roboteq can you give some details on how these overcharged systems caused icing. I have only seen overcharged systems cause icing with refrigeration systems.


Yes, there has to be other issues. The worse I have seen was with a system where the tech had charged a five ton piston metered system to the proper superheat, as per my instructions to him.

When the system, which was already oversized for the appliction most times (School rooms relying on the system to do the job empty or filled with heat producing children) did not cool despite the tech telling me the superheat was right on the money, I checked it out myself.

Well, I get to the job and sure enough, the system is running. A five ton, 10 SEER Goodman with a Bristol recip, it was just humming away....with the compressor and suction service valves encased in crystal hard ice.

I chip away the ice from the service valve and take my superheat. Yep, right on the money. Something that struck me as a possible indication of a problem that the tech did not bother to tell me was the suction line temperature was 4 degrees.

So, into the attic space to take a look at the coil. The coil was so covered with debris (this was a system put back into operation shortly after a major hurricane and it had run without a filter) that I could not even make out that it was a coil.

So, I cleaned up the coil as best I could, fired the thing back up and removed several pounds of refrigerant that the tech had added in order to get the superheat proper with no airflow.


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## nicktech

simply put, in and of itself...NO. could you find an overcharged system icing..Yes, not due to the over charge but to another problem that exists!


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## Swampfox

RoBoTeq said:


> So, I cleaned up the coil as best I could, fired the thing back up and removed several pounds of refrigerant that the tech had added in order to get the superheat proper with no airflow.


I would think the superheat would have been low well before he got the proper amount of refrigerant into the unit, if he was actually measuring superheat, you should have found it undercharged after correcting the airflow issue

more likely he was trying to get the suction pressure up and wasnt measuring superheat


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## RoBoTeq

Swampfox said:


> I would think the superheat would have been low well before he got the proper amount of refrigerant into the unit, if he was actually measuring superheat, you should have found it undercharged after correcting the airflow issue
> 
> more likely he was trying to get the suction pressure up and wasnt measuring superheat


The technician was a government maintenance tech for the school system trying to get air conditioning up and running after a major hurricane hit. So, there is a very good chance he was trying to get the suction temps up, but, the superheat was proper when I first got to the job. The problem of course was having proper superheat with too low of a suction line temperature. The saving grace was a constant heat load.

I have pics of that job in my files somewhere if carnak says it's ok to post them now.


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## nicktech

well what type of metering device was the system equipped with? a TXV system is charged via subcooling and fix orifice is done with superheat. maybe thats the problem.


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## RoBoTeq

nicktech said:


> well what type of metering device was the system equipped with? a TXV system is charged via subcooling and fix orifice is done with superheat. maybe thats the problem.


I'm not looking for a solution, I already resolved the problem. This was in 2005, not a current issue.

The system was fixed metered. That is why I told the technician to charge to proper superheat. I was giving these techs basic charging outlines for them to get many systems up and running and was not specifically going over this one system with them. This was just one of the systems they wanted to know if the hurricane had done damage to. 

My job was to ascertain if the hurricane damaged the systems. There were hundreds of systems that needed to be checked for hurricane damage. This was just one that stuck out because it was operating with it's compressor encased in ice and was severely overcharged.


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## Savage16

RoBoTeq said:


> I've seen compressors encased in ice due to overcharged conditions.


No you have not chubbles


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## hvaclover

Savage16 said:


> No you have not chubbles


look, Robo does not need me to speak for him but compared to your apprenticeship Robin (real name) is a PHD in hvac science.

If you have never seen a comp encased in ice you ain't been around the block.


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## RoBoTeq

Savage16 said:


> No you have not chubbles


Got a nice picture of one in Cayman that was froze up and still operating. Chubbles?


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## hvaclover

RoBoTeq said:


> Got a nice picture of one in Cayman that was froze up and still operating. _*Chubbles?*_


Yeah, that pissed me off just enough answer him in the same vein as he posted.

Guy's an apprentice and he's telling guys with 40 years in the biz stuff don't happen.

Saw a low temp 502 system freeze the comp dome with nothing wrong with. The suction line vapor was below the dew point of the air......


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## RoBoTeq

Poor savage. One day he's going to log into the Internet only to find that even the gay porn sites have had to ban him.


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## Roadhouse

And yet I find another very informative thread with beenthere, RoboTeq and this time Swampfox involved, thanks. 

And now I have to ask, if a system is completely brand new or clean, coil in new condition, duct sizes correct both supply and return, all cfm in perfect order, all equipment the same and the ONLY thing wrong is that there is too much freon, can it freeze?


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## RoBoTeq

Roadhouse said:


> And yet I find another very informative thread with beenthere, RoboTeq and this time Swampfox involved, thanks.
> 
> And now I have to ask, if a system is completely brand new or clean, coil in new condition, duct sizes correct both supply and return, all cfm in perfect order, all equipment the same and the ONLY thing wrong is that there is too much freon, can it freeze?


 Yes. Too much refrigerant returning to the outdoor unit will provide liquid that will flash into vapor in the suction line, accumulator and eventually the compressor causing these components to get cold enough condense and freeze moisture in the atmosphere to them.


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## beenthere

I have never had or seen a system(A/C or heat pump, (not talking about refrigeration units) where all other things were correct. That an over charge lead to anything freezing.


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## hvaclover

I am talking refer and ac.

The ac i saw had a jammed contactor and would not shut off. It ran thru several mild days and it iced back and turned the comp into a snow ball.

When the people who'd been on vacation came home and found it that way and called me. Granted: a one time freak occurrence but it did. The clogged furnace filter didn't help.


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## DuMass

hvaclover said:


> Saw a low temp 502 system freeze the comp dome with nothing wrong with. The suction line vapor was below the dew point of the air......


This seems to be pretty common for walk-in’s using R502, especially when the condenser is located in a basement or boiler room with high humidity.


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## beenthere

hvaclover said:


> I am talking refer and ac.
> 
> The ac i saw had a jammed contactor and would not shut off. It ran thru several mild days and it iced back and turned the comp into a snow ball.
> 
> When the people who'd been on vacation came home and found it that way and called me. Granted: a one time freak occurrence but it did. The clogged furnace filter didn't help.


Ok. But an over charge didn't cause it to freeze up.


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## hvaclover

beenthere said:


> Ok. But an over charge didn't cause it to freeze up.


Yer right but a comp freeze over happened and that's what is important.


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## beenthere

hvaclover said:


> Yer right but a comp freeze over happened and that's what is important.


I think the thread is about freezing from an over charge.


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## RoBoTeq

beenthere said:


> Ok. But an over charge didn't cause it to freeze up.


 If the outdoor unit is running and there is no indoor load because the blower isn't running, what happens? 

The indoor coil winds up flooding, the same as it would if it were overcharged.

What happens when a system is overcharged? 

The superheat drops to zero as liquid refrigerant starts treating the suction line and then the accumulator and finally the compressor (recips) as an evaporator (as the overcharged liquid flashes to a gas in all of these components respectively.)

I've seen some older units build ice monsters that pushed out the unit casings, from overcharge.


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## beenthere

RoBoTeq said:


> If the outdoor unit is running and there is no indoor load because the blower isn't running, what happens?
> 
> The indoor coil winds up flooding, the same as it would if it were overcharged.
> 
> What happens when a system is overcharged?
> 
> The superheat drops to zero as liquid refrigerant starts treating the suction line and then the accumulator and finally the compressor (recips) as an evaporator (as the overcharged liquid flashes to a gas in all of these components respectively.)
> 
> I've seen some older units build ice monsters that pushed out the unit casings, from overcharge.


When I take 16 pounds out of a system. And then recharge it with 6 pounds, like it should have had. Why wasn't the system freezing up.


If the blower isn't running. The system freezes up because there isn't enough heat going through the air side of the coil. For the mass flow rate of the refrigerant. An over charged system. Does mean the mass flow rate of the refrigerant increased. Only the volume of refrigerant in the system increased.

Zero SH in its self doesn't mean a system will freeze up. A vapor line at 50°F can have zero SH. 


Overcharged systems that freeze up. Also have another problem somewhere. Weather it be a restriction in the refrigerant system, and or an air flow issue. There is another problem. 

The overcharged systems you saw froze up. Did you actually measure CFM. And if so, was it 400 CFM per ton?


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## RoBoTeq

beenthere said:


> When I take 16 pounds out of a system. And then recharge it with 6 pounds, like it should have had. Why wasn't the system freezing up.
> 
> 
> If the blower isn't running. The system freezes up because there isn't enough heat going through the air side of the coil. For the mass flow rate of the refrigerant. An over charged system. Does mean the mass flow rate of the refrigerant increased. Only the volume of refrigerant in the system increased.
> 
> Zero SH in its self doesn't mean a system will freeze up. A vapor line at 50°F can have zero SH.
> 
> 
> Overcharged systems that freeze up. Also have another problem somewhere. Weather it be a restriction in the refrigerant system, and or an air flow issue. There is another problem.
> 
> The overcharged systems you saw froze up. Did you actually measure CFM. And if so, was it 400 CFM per ton?


 If this particular system has a txv or other mechanical metering device that controls the superheat, then rather then freezeing up at the outdoor unit, the outdoor unit coil will just fill up with liquid and back up into the compressor.

If this is a fixed metered system and it is overcharged and doesn't freeze it, it is so overcharged that the refrigerant has nowhere to expand for evaporation to take place.


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## nH3man

In residential A/c I can honestly not think of one reason why an overcharged unit would ice up. If you go back to the basics of refrigeration, pressure relates to temperature. An over charged unit typically has a high head which equals a high suction which equals high temperature. If you are asking wether or not overcharging a system, being that all other options have been correctly diagnosed and marked off the list, no an overcharge will not freeze up an evaporator. With that being said, if you are having a problem with a unit freezing up and can not properly diagnose the situation than you should probably get someone who knows whats going on before damage is caused to the compressor.


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## hvaclover

yeah, you're probably right. Guess me and Robo should just disregard the paradoxical experience we both had.


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## nH3man

hvaclover said:


> yeah, you're probably right. Guess me and Robo should just disregard the paradoxical experience we both had.


Im not sure that this is ment for me but I did not read the above posts. I was just simply stating that an overcharged unit, with that being the only problem would not freeze the evaporator. No after reading the above posts I did however not fully understand how some of the answers favoring freezing made since, but I also know that in havc or refrigeration, never doubt what some have seen.


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## beenthere

hvaclover said:


> yeah, you're probably right. Guess me and Robo should just disregard the paradoxical experience we both had.


You posted that you had a system that had other problems besides being overcharged. 

So the overcharge didn't cause the freeze/ice up.


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## RoBoTeq

nH3man said:


> Im not sure that this is ment for me but I did not read the above posts. I was just simply stating that an overcharged unit, with that being the only problem would not freeze the evaporator. No after reading the above posts I did however not fully understand how some of the answers favoring freezing made since, but I also know that in havc or refrigeration, never doubt what some have seen.


 No one said anything about freezing the evaporator. No, an overcharged unit cannot freeze up at the evaporator.

Overcharged units can freeze up along the suction line, at the suction port service valve, accumulator and recip compressors.

After an evap coil freezes up from low air flow; what happens? There is no load on the refrigerant so the normally correct charge becomes an overcharge for the now changed indoor coil air flow. So even in this case, it is the system acting as an overcharged system that causes the outdoor unit components to freeze up. This is what Tranes Snoball was all about.


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## RoBoTeq

beenthere said:


> You posted that you had a system that had other problems besides being overcharged.
> 
> So the overcharge didn't cause the freeze/ice up.


What's the first thing that starts to happen when you overcharge a system? 

Does the suction line not drop in temperature? Does frost not start forming on the suction line and suction line service valve? If you don't know, try it next time you have a tank of refrigerant hooked up to a system.


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## nH3man

RoBoTeq said:


> No one said anything about freezing the evaporator. No, an overcharged unit cannot freeze up at the evaporator.
> 
> Overcharged units can freeze up along the suction line, at the suction port service valve, accumulator and recip compressors.
> 
> After an evap coil freezes up from low air flow; what happens? There is no load on the refrigerant so the normally correct charge becomes an overcharge for the now changed indoor coil air flow. So even in this case, it is the system acting as an overcharged system that causes the outdoor unit components to freeze up. This is what Tranes Snoball was all about.


First off, I was wrong about saying evaporator but none the less I am only expressing a specific point. The first point is that the forum that this was currently posted in is residential. So with that taken into fact, in residential evaporator suction pressure's are above freezing temperature. In the case of an overcharge in a unit with no other problems, the pressure will only go up. Even with saturated liquid flooding back to the compressor, boiling or not , there would not be any freezing due to the high suction pressure caused by the overcharge. Now I would say that you are 100% right about freezing up suction lines, service valves etc. if there was another underlying problem. Also your are 100 % correct that this would happen in refrigeration where a DX coil floods back and suction pressures below freezing would allow iceing as you described. You all seem very knowledgable and Im not saying your wrong I was only considering where the post was posted and by the amount of knowledge of the original poster I highly doubt hes working with 20 ton split system in a freezer.


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## RoBoTeq

nH3man said:


> First off, I was wrong about saying evaporator but none the less I am only expressing a specific point. The first point is that the forum that this was currently posted in is residential. So with that taken into fact, in residential evaporator suction pressure's are above freezing temperature. In the case of an overcharge in a unit with no other problems, the pressure will only go up. Even with saturated liquid flooding back to the compressor, boiling or not , there would not be any freezing due to the high suction pressure caused by the overcharge. Now I would say that you are 100% right about freezing up suction lines, service valves etc. if there was another underlying problem. Also your are 100 % correct that this would happen in refrigeration where a DX coil floods back and suction pressures below freezing would allow iceing as you described. You all seem very knowledgable and Im not saying your wrong I was only considering where the post was posted and by the amount of knowledge of the original poster I highly doubt hes working with 20 ton split system in a freezer.


 I'm referring to fixed metered, recip compressor systems 1-1/2 to 5 ton in residential and light commercial applications. Come to think of it, most of the ones I have seen were in light commercial usage, but that is only because they are more prone to be overcharged due to a dirty filter or indoor coil.

I'll have to find the photos I have of a five tonner that is frozen solid from the service valve to the bottom half of the compressor. That one was in Cayman in a school where the maintenance techs had grossly overcharged the system due to not realizing that the evap coil was packed with dust and sand from the recent hurricane that put me in Cayman.


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## beenthere

RoBoTeq said:


> What's the first thing that starts to happen when you overcharge a system?
> 
> Does the suction line not drop in temperature? Does frost not start forming on the suction line and suction line service valve? If you don't know, try it next time you have a tank of refrigerant hooked up to a system.


Its not like I never overcharged a system. And no, it didn't frost at the service valve.

UNLESS, there was another issue with the system also. The overcharge itself, did not, and will not cause it to freeze up. There has to be a second problem with the system.

Such as the dirty air filters you listed for commercial systems.


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## RoBoTeq

beenthere said:


> Its not like I never overcharged a system. And no, it didn't frost at the service valve.
> 
> UNLESS, there was another issue with the system also. The overcharge itself, did not, and will not cause it to freeze up. There has to be a second problem with the system.
> 
> Such as the dirty air filters you listed for commercial systems.


 Dirty air filters or any other issue that reduces the amount of air across the indoor coil essentially causes the system to become overcharged for the amount of the load. If you overcharge a system that doesn't have air flow issues, you are doing the same thing; dumping liquid refrigerant into the suction line. 

Why would the results not be the same if the same thing is occurring?


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## nH3man

beenthere said:


> Its not like I never overcharged a system. And no, it didn't frost at the service valve.
> 
> UNLESS, there was another issue with the system also. The overcharge itself, did not, and will not cause it to freeze up. There has to be a second problem with the system.
> 
> Such as the dirty air filters you listed for commercial systems.


This is exactly what Im saying, I completely agree with the man Im just stating that with it being the ONLY problem, freezing up is not possible.


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## beenthere

RoBoTeq said:


> Dirty air filters or any other issue that reduces the amount of air across the indoor coil essentially causes the system to become overcharged for the amount of the load. If you overcharge a system that doesn't have air flow issues, you are doing the same thing; dumping liquid refrigerant into the suction line.
> 
> Why would the results not be the same if the same thing is occurring?


Your making a play on wording.

The system is NOT overcharged, just because the air filter is dirty. Its simply a low air flow issue.

And no. If I overcharge a system that doesn't have air flow issues. I have a compressor being flooded. But that doesn't mean the liquid is under 32¨F


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## hvaclover

lol you guys.....hook line and sinker:laughing::laughing::laughing::laughing:


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## beenthere

hvaclover said:


> lol you guys.....hook line and sinker:laughing::laughing::laughing::laughing:


The report button, is only to be used to report threads or post that violate rules. 

Use other then that, is in itself a violation.


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## hvaclover

beenthere said:


> The report button, is only to be used to report threads or post that violate rules.
> 
> Use other then that, is in itself a violation.


huh?

who pushed the button


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## beenthere

hvaclover said:


> huh?
> 
> who pushed the button


Response went into the wrong thread.

So another guy is reading about over charges now. LOL


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## RoBoTeq

beenthere said:


> Your making a play on wording.
> 
> The system is NOT overcharged, just because the air filter is dirty. Its simply a low air flow issue.
> 
> And no. If I overcharge a system that doesn't have air flow issues. I have a compressor being flooded. But that doesn't mean the liquid is under 32¨F


 I'm not playing with words. I'm trying to show you that the results of liquid returning to the outdoor unit results in freezing no matter what the reason for it.

What the hell is the difference between liquid returning to the outdoor unit because of low indoor air flow or liquid returning to the outdoor unit because of system overcharge?

It is the process of evaporation that absorbs heat and lowers temperature; will you agree with this?

When liquid refrigerant enters the suction line and is allowed to boil off (evaporate), it absorbs the heat in the suction line, reducing the temperature; will you agree to "this"?

Unless a system is so grossly overcharged that the refrigerant stays liquid all the way back to the compressor, and then some to fill up the can of the compressor, anywhere the liquid boils off (evaporates), it absorbs heat and drops the temperature of that component; will you agree with this?

Not just once, but several times, I have seen overcharged units that have formed ice monsters so big around the accumulators and compressors that the ice has buckled the cabinetry of the units. This is usually after years of neglect of a system resulting in one gauge techs topping off the system instead of cleaning the evap coil. Then, another tech notices that their is little air through the system and cleans the coil, but doesn't adjust the charge. Now everything else in the system is proper except that it is overcharged....and it freezes up. 

Once a system is so overcharged that there is no evaporation of the liquid refrigerant happening anywhere, it is not going to freeze up but is going to wipe out the compressor.


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## hvaclover

RoBoTeq said:


> I'm not playing with words. I'm trying to show you that the results of liquid returning to the outdoor unit results in freezing no matter what the reason for it.
> 
> What the hell is the difference between liquid returning to the outdoor unit because of low indoor air flow or liquid returning to the outdoor unit because of system overcharge?
> 
> It is the process of evaporation that absorbs heat and lowers temperature; will you agree with this?
> 
> When liquid refrigerant enters the suction line and is allowed to boil off (evaporate), it absorbs the heat in the suction line, reducing the temperature; will you agree to "this"?
> 
> Unless a system is so grossly overcharged that the refrigerant stays liquid all the way back to the compressor, and then some to fill up the can of the compressor, anywhere the liquid boils off (evaporates), it absorbs heat and drops the temperature of that component; will you agree with this?
> 
> Not just once, but several times, I have seen overcharged units that have formed ice monsters so big around the accumulators and compressors that the ice has buckled the cabinetry of the units. This is usually after years of neglect of a system resulting in one gauge techs topping off the system instead of cleaning the evap coil. Then, another tech notices that their is little air through the system and cleans the coil, but doesn't adjust the charge. Now everything else in the system is proper except that it is overcharged....and it freezes up.
> 
> Once a system is so overcharged that there is no evaporation of the liquid refrigerant happening anywhere, it is not going to freeze up but is going to wipe out the compressor.


Robin i don't think you are going to win over Beenthere with _*BS*_ and _*Brilliance.*_

you said it your self you love to needle people (and I love to come along on the ride when you do cause it's a lot of fun) but Been is unflappable.

You two will be at it for pages... well considering Been's quiet cool and your biting flamboyance, this might be like watching an irresistible force netting an immovable object:laughing::laughing::devil2::w00t::boxing::boxing:


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## beenthere

RoBoTeq said:


> I'm not playing with words. I'm trying to show you that the results of liquid returning to the outdoor unit results in freezing no matter what the reason for it.
> 
> What the hell is the difference between liquid returning to the outdoor unit because of low indoor air flow or liquid returning to the outdoor unit because of system overcharge?
> 
> It is the process of evaporation that absorbs heat and lowers temperature; will you agree with this?
> 
> When liquid refrigerant enters the suction line and is allowed to boil off (evaporate), it absorbs the heat in the suction line, reducing the temperature; will you agree to "this"?
> 
> Unless a system is so grossly overcharged that the refrigerant stays liquid all the way back to the compressor, and then some to fill up the can of the compressor, anywhere the liquid boils off (evaporates), it absorbs heat and drops the temperature of that component; will you agree with this?
> 
> Not just once, but several times, I have seen overcharged units that have formed ice monsters so big around the accumulators and compressors that the ice has buckled the cabinetry of the units. This is usually after years of neglect of a system resulting in one gauge techs topping off the system instead of cleaning the evap coil. Then, another tech notices that their is little air through the system and cleans the coil, but doesn't adjust the charge. Now everything else in the system is proper except that it is overcharged....and it freezes up.
> 
> Once a system is so overcharged that there is no evaporation of the liquid refrigerant happening anywhere, it is not going to freeze up but is going to wipe out the compressor.


Its not the over charge. Its the other things that are causing the freeze up. 



Officer. It wasn't me having my foot to the floor that caused my car to exceed the speed limit. it was the fact that I'm driving down a hill, that caused my car to go 140 MPH. Honestly, full throttle had nothing to do with it.


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## RoBoTeq

beenthere said:


> Its not the over charge. Its the other things that are causing the freeze up.
> 
> 
> 
> Officer. It wasn't me having my foot to the floor that caused my car to exceed the speed limit. it was the fact that I'm driving down a hill, that caused my car to go 140 MPH. Honestly, full throttle had nothing to do with it.


 Really? And here I thought it was liquid refrigerant flashing into a gas that made where ever it changed state the evaporator portion of the unit. And I thought that when an evaporator portion of a unit that had no airflow to create load would drop below freezing to first condense and then freeze the moisture in the air. Is that not what is happening when a unit is overcharged?


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## RoBoTeq

hvaclover said:


> Robin i don't think you are going to win over Beenthere with _*BS*_ and _*Brilliance.*_
> 
> you said it your self you love to needle people (and I love to come along on the ride when you do cause it's a lot of fun) but Been is unflappable.
> 
> You two will be at it for pages... well considering Been's quit cool and your biting flamboyance, this might be like watching an irresistible force netting an immovable object:laughing::laughing::devil2::w00t::boxing::boxing:


 I can do this for the rest of my life. Hell, I've seen guys who judge that a system is charged when the suction line starts to sweat and determine it is "overcharged" if the suction line frosts.


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## beenthere

RoBoTeq said:


> Really? And here I thought it was liquid refrigerant flashing into a gas that made where ever it changed state the evaporator portion of the unit. And I thought that when an evaporator portion of a unit that had no airflow to create load would drop below freezing to first condense and then freeze the moisture in the air. Is that not what is happening when a unit is overcharged?


Not like your making it out to be.

I can take a brand new unit. Make sure it has 400 CFM per ton air flow, correct. And while operating at an indoor of 75 and outdoor of 85. Slowly add refrigerant until the compressor drowns. And it will not freeze up. 

I could add 4 ounces every 10 minutes, and it would not freeze up. Until I changed another condition.

Seen lots of heat pumps that were overcharge in winter. Come summer. They aren't cooling. And they aren't freezing up either.


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## nH3man

RoBoTeq said:


> Really? And here I thought it was liquid refrigerant flashing into a gas that made where ever it changed state the evaporator portion of the unit. And I thought that when an evaporator portion of a unit that had no airflow to create load would drop below freezing to first condense and then freeze the moisture in the air. Is that not what is happening when a unit is overcharged?


Flashing is the result of the refrigerant boiling at a temperature that is above the boiling point for that specific pressure. If you overcharge brand spankin new unit and the suction was 83 psig which would be around 49F, whether it was flashing or not the results would not be freezing up. The reason for the flashing is the ambient temperatures around the pipe are higher than the 49F. So the liquid now occupying the suction pipe is building pressure, becoming warmer and moving its way to the compressor. The main theory of heat transfer is from hot to cold. Would you not agree that with the lower temperature being 49F due to a high suction pressure that temperatures below that would not be achievable. As liquid boils its not the pipe cooling down it is its surroundings exchanging the heat. If you have liquid in a pipe at 83psig equaling 49F, are you saying that as it flashes off the temperature goes down,thats not possible. Its absorbing heat as it is flashing which in turn only makes the temperature go up. The only reduction in temperature is at the point of expansion when a 225psig head turns into a 72psig suction, after that point the temperature and pressure only goes up due to heat tranfer. Take for example charging a system from a fresh vacuum, as soon as liquid exits your gauge port what happens. It freezes up due to the vacuum. Now as soon as the suction pressure rises above 57.8 which would be 32F the ice melts away. The basics of refrigeration still apply no matter what, Pressure relates to temperature. If your ONLY problem was an overcharged unit from a unexperienced tech, the results would be a high head and high suction pressure. If you walked up to a unit that had ice on the compressor, service valves etc would your first thought honestly be overcharge, NO. Now with further investigation you might find exactly what you are saying caused the icing but it would be another problem with the overcharge factor. Not just an over charge. I completely understand what your saying (3rd time saying this) but it seems that you are refusing to understand that this is a very simple question with a very simple answer. Im sure we can all give reasons why a system would freeze up and at this point it would seem that a whole new forum should be created to justify that.


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## nH3man

RoBoTeq said:


> I can do this for the rest of my life. Hell, I've seen guys who judge that a system is charged when the suction line starts to sweat and determine it is "overcharged" if the suction line frosts.


Well I guess now when I hire someone I better ask them what they would assume if they seen a unit freezing up. Thanks for the heads up. I dont think that the first assumption I would want for my techs to have when they saw a frozen up unit in residential is that its overcharged.


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## RoBoTeq

nH3man said:


> Well I guess now when I hire someone I better ask them what they would assume if they seen a unit freezing up. Thanks for the heads up. I dont think that the first assumption I would want for my techs to have when they saw a frozen up unit in residential is that its overcharged.


I absolutely agree that when we see a frozen outdoor unit we do not think first about overcharge. I can also see where in all of the frozen units I have worked on, there were extenuating circumstances leading to the overcharging of the system which ultimately froze up. 

Of course, I remedy the real problems before realizing that the systems are overcharged, so I may be associating the systems now being in proper operation except for being overcharged as being overcharged being the reason for them being frozen up. 

I think I finally get what you guys are saying and where I am making my mistake in my thought process. Now I have to start overcharging a new system to see if I can get the service valve to start frosting.


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## nH3man

RoBoTeq said:


> I absolutely agree that when we see a frozen outdoor unit we do not think first about overcharge. I can also see where in all of the frozen units I have worked on, there were extenuating circumstances leading to the overcharging of the system which ultimately froze up.
> 
> Of course, I remedy the real problems before realizing that the systems are overcharged, so I may be associating the systems now being in proper operation except for being overcharged as being overcharged being the reason for them being frozen up.
> 
> I think I finally get what you guys are saying and where I am making my mistake in my thought process. Now I have to start overcharging a new system to see if I can get the service valve to start frosting.


Yes sir, thats all I was saying. Your 100 % correct on your theory and I have been behind numerous techs that wrongfully diagnosed a dirty coil and shoved a couple of pounds of refrigerant in which only increased the problem at hand. On the positive side I can say that this experience has been enjoyable and I look forward to more threads like it. You all seem very knowledgable and challenges always keep the mind sharp.


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## hvaclover

RoBoTeq said:


> I can do this for the rest of my life. Hell, I've seen guys who judge that a system is charged when the suction line starts to sweat and determine it is "overcharged" if the suction line frosts.


 On domestic refrigs the frost back method was a factory prescribed method
when I was a rookie. But then they came out with field chargers like dail-a-charge. We didn't have scales accurate enough for the critical charged cap tube system's so the frost back was a great way to know if you hadenough charge.

Charge just a little at at time with the refrig empty and as soon as the frost line showed it self out side the cabinet uou would stop. You let the box run over night and trimmed the charge back a little at a time 'til the frost line disappeared.

If I ever did a resi refer comp replacement I would do it the same way. Even 134A is ok to charge by frost line.:001_tongue:


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## hvaclover

[LEFT said:


> nH[/LEFT]3man;4240]Yes sir, thats​ all I was saying. Your 100 % correct on your theory and I have been behind numerous techs that wrongfully diagnosed a dirty coil and shoved a couple of pounds of refrigerant in which only increased the problem at hand. On the positive side I can say that this experience has been enjoyable and I look forward to more threads like it. You all seem very knowledgeable and challenges always keep the mind sharp.


As a person in business for over 35 years I can honestly say that when ever Robo​ or Beenthere​ have differences of opinion with any body it usually lasts for pages, and I always come a way from the thread either understanding a concept much better or learn something I had no idea of previously


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## beenthere

I still charge/check charge on those little resi(and some commercial ones) refers like that. When I have to work on one.

And you can see where I specified I was talking about A/C in one of my earlier post. That was because of those refers.


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## nH3man

hvaclover said:


> As a person in business for over 35 years I can honestly say that when ever Robo​or Beenthere​have differences of opinion with any body it usually lasts for pages, and I always come a way from the thread either understanding a concept much better or learn something I had no idea of previously


Well, as a 26 year old with a third of the years you have in I can so this. I was taught that if you think your right argue. If you dont how will you ever know your wrong. Another lesson is dont learn by repetition, know the theory.


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## DuMass

beenthere said:


> I still charge/check charge on those little resi(and some commercial ones) refers like that. When I have to work on one.
> 
> And you can see where I specified I was talking about A/C in one of my earlier post. That was because of those refers.


Not to hijack, but I will also occasionally charge a window unit by frost line and evap temp in a pinch.
Although I rarely work on them, these things are usually on their last legs anyway and since you can often buy a new one for under a hundred bucks at WallyWorld or HD, they are not worth putting a lot of effort into.


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## beenthere

I remind those customers. that they can probably but 2 new window shakers. For what it will cost them for me to put in just a few ounces of refrigerant.


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## RoBoTeq

hvaclover said:


> On domestic refrigs the frost back method was a factory prescribed method
> when I was a rookie. But then they came out with field chargers like dail-a-charge. We didn't have scales accurate enough for the critical charged cap tube system's so the frost back was a great way to know if you hadenough charge.
> 
> Charge just a little at at time with the refrig empty and as soon as the frost line showed it self out side the cabinet uou would stop. You let the box run over night and trimmed the charge back a little at a time 'til the frost line disappeared.
> 
> If I ever did a resi refer comp replacement I would do it the same way. Even 134A is ok to charge by frost line.:001_tongue:


 Oh, I agree. I've reverted to many old school ways of charging when I didn't have the proper tools on hand. This happens to me more often then one would think because I am not in the field with my own tools any longer, so I have to work with what the tech du jour has on hand.

Vacuum pump? We don't need no stinking vacuum pumps. I clearly recall the instructions saying to purge (diminimus, of course) the lines for 15 seconds for 25' of line and 2 seconds for every 10 foot of line thereafter.


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## RoBoTeq

hvaclover said:


> As a person in business for over 35 years I can honestly say that when ever Robo​
> 
> or Beenthere​
> have differences of opinion with any body it usually lasts for pages, and I always come a way from the thread either understanding a concept much better or learn something I had no idea of previously


I think most of that is because beenthere and I look at things from different points of view and expressing ourselves in different ways. 90% of the time it turns out we are thinking the same thing but saying it in different ways.

We have also had some opinion conversations in which I too have learned quite a bit, even though I wind up keeping my opinion. One that comes to mind is the value and benefits of variable speed blowers.

I won't keep up an argument unless I feel there is a possibility that I might learn something.


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## RoBoTeq

nH3man said:


> Well, as a 26 year old with a third of the years you have in I can so this. I was taught that if you think your right argue. If you dont how will you ever know your wrong. Another lesson is dont learn by repetition, know the theory.


 It's good to know that young people with this attitude are replacing we old timers. Nothing irks me more then to hear someone my age bracket complain that the newbies in our industry are just a bunch of lazy punks. From what I have seen, there are more younger techs wanting and willing to know "why" they do what they do then there are older techs having any clue as to why they do the things they have been taught to do.

This thread is a prime example of an older tech who has only seen a particular issue after other issues have been resolved. So, I was only seeing the issue from one viewpoint and not understanding what others were talking about. Sort of like me looking a woman with a dog face not understanding why the guy standing behind her looking at her smoking hot butt is saying how great looking she is.


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## RoBoTeq

DuMass said:


> Not to hijack, but I will also occasionally charge a window unit by frost line and evap temp in a pinch.
> Although I rarely work on them, these things are usually on their last legs anyway and since you can often buy a new one for under a hundred bucks at WallyWorld or HD, they are not worth putting a lot of effort into.


 Not a hijack at all. This fits right in with the conversation and supports where my thought pattern was coming from.


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## RoBoTeq

beenthere said:


> I remind those customers. that they can probably but 2 new window shakers. For what it will cost them for me to put in just a few ounces of refrigerant.


 6,000 Btu window units for $99 at Lowe's two years ago. I bought three of them for the upstairs of the old farmhouse I was living in while I worked on the attic system. Darned things worked great and were not really that noisy at all.


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## beenthere

RoBoTeq said:


> 6,000 Btu window units for $99 at Lowe's two years ago. I bought three of them for the upstairs of the old farmhouse I was living in while I worked on the attic system. Darned things worked great and were not really that noisy at all.


Ya. I can't believe some people actually think I can fix it for less then 99 bucks.


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## nH3man

RoBoTeq said:


> It's good to know that young people with this attitude are replacing we old timers. Nothing irks me more then to hear someone my age bracket complain that the newbies in our industry are just a bunch of lazy punks. From what I have seen, there are more younger techs wanting and willing to know "why" they do what they do then there are older techs having any clue as to why they do the things they have been taught to do.
> 
> This thread is a prime example of an older tech who has only seen a particular issue after other issues have been resolved. So, I was only seeing the issue from one viewpoint and not understanding what others were talking about. Sort of like me looking a woman with a dog face not understanding why the guy standing behind her looking at her smoking hot butt is saying how great looking she is.


 Thats funny! You know honestly I lucked out and have had the opportunity to work with some of the best men out there in refrigeration. I mainly work on ammonia refrigerated equipment and large tonnage freon systems. You know the 2 guys that have helped me the most, I honestly have almost ended up fighting on several occassions due to not seeing eye to eye on issues. Its this reason that both men are my best friends and it was the challenge that enabled me to become a mechanical contractor by the age of 26. More than once I was wrong about situations and before Ill give up on a theory it will need to be explained in great detail why Im wrong.


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## josuevos

Overcharged....doubt it. Clogged evap...duh!


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