Thank you for another important and extremely well done video. I am so happy you explained about sight glasses and residential installations. Carrier wants those systems using TEVs charged by the sub cooling method and weigh in method for new installs using over 25 ft of 3/8 liquid line. As you said, just because the sight glass is clear, does not mean the charge is up to the manufactures specifications. And, no, close enough does NOT count. In commercial equipment, as you said the sight glass is helpful, BUT, not the be all, end all answer. Thanks again for another great and accurate video!
Should the sight glass be installed horizontally or vertically? I saw one installed vertically and could see a solid strong stream of liquid falling from top to bottom, and the fridge was cooling perfectly, but the sight glass wasn't full?
At 3:25 you are explaining it opposite. Typically need more refrigerant during winter as the headmaster bypasses and backs liquid into the condenser to maintain head pressure. If the system was only charged to a clear sight glass when installed in warmer weather, you could end up being very low when the headmaster bypasses to the point you lose liquid seal and the headmaster is wide open and just feeding boiled gas to the expansion valve. I have had units do this and start bouncing off the low pressure control.
Ty this is a little off topic and probably out of order from your teachings but I’d love if you did a video on green wheels. Function, purpose and material it’s made of and why.
Yes sir. It will be a good bit before I get to the ER wheels and ERV there and I have a difficult time sourcing used ones in my price range of free. There is a lot to unpack, good bad and ugly.
Is it just me? Nowhere on Google/TH-cam can I find a simple guide on how to read a sight glass. I don't need theory. If a sight glass looks like (A), it means (B). If a sight glass looks like (C), it means (D). etc. Anyway, our HVAC guy is having a look tomorrow, maybe he can tell me.
A sight glass alone is not used to diagnose a system but a tool that provides more information assisting in diagnosing. Interpreting a sight glass should be left to an HVAC professional. If you want the simple "it looks like/it means" here it is. If the color in the center matches the color in the outside ring under "WET" it means there is moisture that will turn to acid and kill the system. If the color in the center matches the outer ring under "DRY" then there is no moisture. If the metal is anything other than shinny brass there are contaminants in the system need to be cleaned. If the system is running near operating conditions and the sight glass is clear it means it's extremely undercharged with only vapor or charged correctly with liquid, or overcharged with liquid. If there are bubbles in the sight glass it means it's undercharged, has non condensables, or not yet operating close to design conditions.
Late to the party I know. Sight glass is a tool for the technical primarily. First we have to assume that the sight glass is installed with an expansion valve metered evaporator coil. If not then it is useless. It should only be installed as close to the metering device as possible. Always. However, if the lines et is 30' or less and sized correctly then most of the time you can get away with it. Always verify sub cool. If you have a lineset much longer than that and it is installed at the outdoor unit then you will have bubbles or periods of clearing and bubbles. Sub cool should also be checked at the evaporator. Can't tell you how many times I've had to correct an overcharge at town houses and condos because the tech pumped it up to clear the sight glass. For the home owner. If you are having cooling issues and see bubbles in the sight glass then call a tech. Could be low or could be something else like a bad txv. It's not something to worry about as there really isn't a lot you can do on your end. If you see occasional bubbles that clear up and go away that is most likely normal operation. Especially on a really hot day. Hope that helps. Appreciate the video.
Hi there and thx for the video, so I was told that in order to remove a moisture contaminated system, you'll also need to remove the compressor oil. I made a mistake and didn't get a good vacuum and now head pressure reveals non-condensables with the aid a poor pump and hose. Yikes!!! Any suggestions TY Branaman??
If it's POE oil, then you may need to change the oil. POE is hygroscopic, meaning it has an affinity for moisture. Once water gets in it turns to an acid. It is possible to pull moisture out of POE oil with multiple fiter drier changes. Either way moisture in POE oil is a pain in the @$$.
Great video, thank you. I'm moving from residential AC to refrigeration and all I've been hearing is "clear the glass". However, I've noticed many machines off on high limit that have flashing glasses (checked dirty condenser, fan blade position, RPMs etc. ). It was during that heat wave we had a few weeks ago and none of the glasses would clear ( especially 404A ) I started reading up on it and I've read that the best way to check a charge is to see the receiver is 80% filled regardless of the sight glass. Is this true? Thank you again!!
Yes, a receiver should never be over 80% full during pump down. A sight glass is a tool bit it's not a complete method of charging. Especially during a hot pull down, the charge could be good and the sight glass flashing. Condensor being clean is also very important.
The site glass,liquid drier & subcool reading I do inside as close to the metering device as possible,that's what peirce Phelps taught. I don't install site glasses. What does a black dot mean (acid)! 🥃🥃🍺🍺🍺🎳🍇 Stay safe. Retired (werk'n)keyboard super tech. Wear your safety glasses.
I forgot to mention the black dot! I've installed most of my sight glasses inside after the drier before the metering device. Nobody told me that, it just makes sense to me. It's measuring knowing others teach my that way. That seems to really upset people. I've been caused out for that before. I agree with you it's usually the best place. I don't like a drier in a walk in though.
hi .as we know, the moisture inside the refrigerant system can damage the compressor..So, how to identify if there any moisture that exist inside the refrigerant system?? is there any alternate prevention or method to avoid the moisture from damage the compressor from the early stage??
The moisture indicator in the sight glass is 1 We can also use an acid checking tool and test a sample of refregerant or refregerant lol. The moisture is going to get in by #1 improper evacuation/dehydration ie not a dream enough vacuum in microns. #2 not purging the hoses properly when servicing, or bleeding the HP threw they manifold gauge set. #3 leak in the system on the LP side that causes the unit to go into a vacuum pulling moisture in. Units over 30 years old have 0 moisture in them.
Ac systom circualingtime drit moster filshioin need coprssar pard damerges some ttime this liuqud the circulating mostisure may harm the motor winding and valves because if high suction pressure the boiling point of liquuid in the eva porator of water coiler bottlw cooer ac is above 32°f amd moisture inside wil not freeze in such machiesdrier filtres are not required nly strainers arerequired to removeig dust particles .but in some ac and watrcoolers drier filtr is used stop the circulation of moisture throgh the systom thrd typ 2side weding type sight glss fee size sam derfrnt typed fee varus typ of moisture in dicators are ftted in the sytem to indicate the presence of mosture the liquied line moisture idicator turingpik or orange if dangerous amount of moisure is preset and reen or blue if the refrigerant is dry some times a filter is mounted i the suction line also to perevnt foregn particls entering the compressor dire cap city on compressor motor hp ...drier size cubic iches comprssor moto hp ..using 2i ..hp or exls 1/8..3..1/6to 1/4 ..6 ....1/4 t1/2 ... 6 ..1/4to1/2...9 .1/2to3/4 ..9..1/2to3/4 ..12..3/4to 1" ..30 .1/2to3 "usinexpls
No, no matter the refrigerant, you don’t want any bubbles, bubbles mean it is not a subcooled liquid or you don’t have enough refrigerant in your system.
Thank you for another important and extremely well done video.
I am so happy you explained about sight glasses and residential installations.
Carrier wants those systems using TEVs charged by the sub cooling method and weigh in method for new installs using over 25 ft of 3/8 liquid line.
As you said, just because the sight glass is clear, does not mean the charge is up to the manufactures specifications. And, no, close enough does NOT count.
In commercial equipment, as you said the sight glass is helpful, BUT, not the be all, end all answer.
Thanks again for another great and accurate video!
Should the sight glass be installed horizontally or vertically? I saw one installed vertically and could see a solid strong stream of liquid falling from top to bottom, and the fridge was cooling perfectly, but the sight glass wasn't full?
At 3:25 you are explaining it opposite. Typically need more refrigerant during winter as the headmaster bypasses and backs liquid into the condenser to maintain head pressure. If the system was only charged to a clear sight glass when installed in warmer weather, you could end up being very low when the headmaster bypasses to the point you lose liquid seal and the headmaster is wide open and just feeding boiled gas to the expansion valve. I have had units do this and start bouncing off the low pressure control.
Great video .you pointed me in the right direction.
Thx ty for sharing your knowledge and videos.
Ty this is a little off topic and probably out of order from your teachings but I’d love if you did a video on green wheels. Function, purpose and material it’s made of and why.
Yes sir.
It will be a good bit before I get to the ER wheels and ERV there and I have a difficult time sourcing used ones in my price range of free.
There is a lot to unpack, good bad and ugly.
Interesting I’ve been working on a few units with them and only ever heard them called green wheels. At least I know their names now.
Is it just me? Nowhere on Google/TH-cam can I find a simple guide on how to read a sight glass. I don't need theory. If a sight glass looks like (A), it means (B). If a sight glass looks like (C), it means (D). etc. Anyway, our HVAC guy is having a look tomorrow, maybe he can tell me.
A sight glass alone is not used to diagnose a system but a tool that provides more information assisting in diagnosing. Interpreting a sight glass should be left to an HVAC professional.
If you want the simple "it looks like/it means" here it is.
If the color in the center matches the color in the outside ring under "WET" it means there is moisture that will turn to acid and kill the system.
If the color in the center matches the outer ring under "DRY" then there is no moisture.
If the metal is anything other than shinny brass there are contaminants in the system need to be cleaned.
If the system is running near operating conditions and the sight glass is clear it means it's extremely undercharged with only vapor or charged correctly with liquid, or overcharged with liquid.
If there are bubbles in the sight glass it means it's undercharged, has non condensables, or not yet operating close to design conditions.
Late to the party I know. Sight glass is a tool for the technical primarily. First we have to assume that the sight glass is installed with an expansion valve metered evaporator coil. If not then it is useless. It should only be installed as close to the metering device as possible. Always. However, if the lines et is 30' or less and sized correctly then most of the time you can get away with it. Always verify sub cool. If you have a lineset much longer than that and it is installed at the outdoor unit then you will have bubbles or periods of clearing and bubbles. Sub cool should also be checked at the evaporator. Can't tell you how many times I've had to correct an overcharge at town houses and condos because the tech pumped it up to clear the sight glass. For the home owner. If you are having cooling issues and see bubbles in the sight glass then call a tech. Could be low or could be something else like a bad txv. It's not something to worry about as there really isn't a lot you can do on your end. If you see occasional bubbles that clear up and go away that is most likely normal operation. Especially on a really hot day. Hope that helps. Appreciate the video.
a sight glass will meter the refrigerant correct so a 3 4 5 ton is not going to do its purpose but a sight glass works with what amout of BTU
Hi there and thx for the video, so I was told that in order to remove a moisture contaminated system, you'll also need to remove the compressor oil. I made a mistake and didn't get a good vacuum and now head pressure reveals non-condensables with the aid a poor pump and hose. Yikes!!!
Any suggestions TY Branaman??
If it's POE oil, then you may need to change the oil.
POE is hygroscopic, meaning it has an affinity for moisture. Once water gets in it turns to an acid.
It is possible to pull moisture out of POE oil with multiple fiter drier changes. Either way moisture in POE oil is a pain in the @$$.
thanks beste Man....
Great video, thank you. I'm moving from residential AC to refrigeration and all I've been hearing is "clear the glass". However, I've noticed many machines off on high limit that have flashing glasses (checked dirty condenser, fan blade position, RPMs etc. ). It was during that heat wave we had a few weeks ago and none of the glasses would clear ( especially 404A ) I started reading up on it and I've read that the best way to check a charge is to see the receiver is 80% filled regardless of the sight glass. Is this true? Thank you again!!
Yes, a receiver should never be over 80% full during pump down.
A sight glass is a tool bit it's not a complete method of charging.
Especially during a hot pull down, the charge could be good and the sight glass flashing.
Condensor being clean is also very important.
Be sure to check out my friend Chris Stevens with HVACR Videos. He has excellent commercial videos
Good job
The site glass,liquid drier & subcool reading I do inside as close to the metering device as possible,that's what peirce Phelps taught.
I don't install site glasses.
What does a black dot mean (acid)!
🥃🥃🍺🍺🍺🎳🍇
Stay safe.
Retired (werk'n)keyboard super tech. Wear your safety glasses.
I forgot to mention the black dot!
I've installed most of my sight glasses inside after the drier before the metering device. Nobody told me that, it just makes sense to me. It's measuring knowing others teach my that way. That seems to really upset people. I've been caused out for that before. I agree with you it's usually the best place. I don't like a drier in a walk in though.
Yes but this is mostly for refrigeration where a sight glass is almost always needed. In addition, SC is rarely used in refrigeration.
hi .as we know, the moisture inside the refrigerant system can damage the compressor..So, how to identify if there any moisture that exist inside the refrigerant system?? is there any alternate prevention or method to avoid the moisture from damage the compressor from the early stage??
The moisture indicator in the sight glass is 1
We can also use an acid checking tool and test a sample of refregerant or refregerant lol.
The moisture is going to get in by
#1 improper evacuation/dehydration ie not a dream enough vacuum in microns.
#2 not purging the hoses properly when servicing, or bleeding the HP threw they manifold gauge set.
#3 leak in the system on the LP side that causes the unit to go into a vacuum pulling moisture in.
Units over 30 years old have 0 moisture in them.
Ac systom circualingtime drit moster filshioin need coprssar pard damerges some ttime this liuqud the circulating mostisure may harm the motor winding and valves because if high suction pressure the boiling point of liquuid in the eva porator of water coiler bottlw cooer ac is above 32°f amd moisture inside wil not freeze in such machiesdrier filtres are not required nly strainers arerequired to removeig dust particles .but in some ac and watrcoolers drier filtr is used stop the circulation of moisture throgh the systom thrd typ 2side weding type sight glss fee size sam derfrnt typed fee varus typ of moisture in dicators are ftted in the sytem to indicate the presence of mosture the liquied line moisture idicator turingpik or orange if dangerous amount of moisure is preset and reen or blue if the refrigerant is dry some times a filter is mounted i the suction line also to perevnt foregn particls entering the compressor dire cap city on compressor motor hp ...drier size cubic iches comprssor moto hp ..using 2i ..hp or exls 1/8..3..1/6to 1/4 ..6 ....1/4 t1/2 ... 6 ..1/4to1/2...9 .1/2to3/4 ..9..1/2to3/4 ..12..3/4to 1" ..30 .1/2to3 "usinexpls
Excellent vid. That last example, system short of gas?
Yes, we where charging several units and has the opportunity to show a variety of views of bubbles
What does it mean when the refrigerant crosing the sight glass is miky, white , not clear
Low on charge, non condensables or contaminants.
Very good
So bubbles are OK, if its a mixed refridgerant?
No, no matter the refrigerant, you don’t want any bubbles, bubbles mean it is not a subcooled liquid or you don’t have enough refrigerant in your system.
@@tristanhamel1839 Thanks!
on the topic of stupid questions nobody asks: does the moistuire indicator "reset" if you vaccum the system or does it needs to be replaced?
Most Yes, once you pull a deep vacuum it pulls the moisture out. Some need a little run time before the "reset"
What kind of refrigerant was it?
in a real world scenario its not ideal to put a sight glass right next to metering device. I usually put it in front of the filter.
www.achrnews.com/articles/143707-where-to-install-the-liquid-line-sight-glass
yep
Where boes this filter is in stall before the condenser filter or compressor let me know please thanks you God bless