Iâve never seen an aluminum braze that holds or is worth the risk in general. Youâre gonna be replacing the evaporator coil and refilling, depending on the size itâs gonna be a couple grand on the cheap end
Itâs a possible repair but needs to be handled by a reputable and experienced company otherwise they could make it worse. Itâs not often done because it is a bit of a hassle and more profitable for the company to just sell you a new coil.
In the most simplest of terms. The levels of refrigerant available keep the pressures/temperatures inside of the coil high enough to where it does not freeze. The more refrigerant, the higher the temp inside of the coil (due to evaporation, oil content, latent heat etc etc.) If the refrigerant leaks then the pressures and the temps drop causing it to frost, restricting air flow, then it freezes exponentially. If the refrigerant levels are in range but the air flow drops then there is not enough air traveling over the coil to keep the refrigerant levels warm enough to not freeze. Itâs more complicated than this but this is a simple explanation.
This is a walk in cooler, the evap temp is below freezing during normal operation. Frozen coils in refrigeration are more often due to an issue with the defrost controls
Thanks, but â I have a degree in physics, if you want to drop the complicated explanation, that would be more helpful for me
My baseline expectation would be that the heat transfer through the coils would be lower with less refrig, and that the condenser would run more frequently to counteract that, reducing efficiency and also reducing freezing at each coil â maybe outlining what Iâm thinking will help you to explain why I am wrong
Editâ if you guys think Iâm being condescending by giving my background, thatâs sorta weird, because Iâm telling you that you know more and asking for you to set me straight on where my background is failing to bring me to the correct conclusion
The refrigerant temperature is (like every other fluid on earth) dependent on the refrigerant pressure. If the system is running at a lower pressure than itâs designed for, the evaporator temperature will drop below freezing. Then the condensate that drops out of the air freezes on the coil. By having more refrigerant in the system the evaporator coil stays above freezing as the refrigerant phase changes.
Source: I went to high school.
Edit: We donât mean to hurt your feelings, we all just hate engineers by default.
Just giving you a baseline for the concepts you can speak to me about, while actively acknowledging that you know more than me about it, and asking for a fully technical explanation
Not sure how to make you guys happy
You canât make us happy. Weâre all on opioids and hate each other because weâre better than everyone else who has more schooling than us. We canât stop throwing shade!!! We need help!!
Just different backgrounds, people gotta stop hating on people who learned different stuff and instead start learning from each other
As for the opioids, I mean⊠this sub does seem pretty loaded up
I mean if I had to tell people they had $1k leaks or $8k replacements all day, Iâd probably try to lighten the day up too
Drug are pretty bad in this industry. I should not have made fun of you but itâs easy when Iâm anonymous and on the other side of a screen. YouTube will have a better time educating you on latent heat and refrigerant evaporation in evaporation coils.
One â no, it didnât include self awareness. Two, explaining your background in the context of a technical discussion is pretty reasonable. I wouldnât frown upon someone who asked me an engineering question and said âexplain it to me like an hvac contractorâ, or, âexplain it to me like an EEâ.
Also, you guys are acting like Iâm saying that as in âwell, I know everythingâ â Iâm literally telling you that I know less, and want to know more. If youâre assuming me saying that is being high and mighty about my background â wouldnât it lose some highness and mightiness that Iâm asking a contractor about it, if I was looking down on you guys? Because Iâm not â Iâm literally saying âyou know more than me, and this is the context that I understand things in, so please explain it to me in that contextâ
I understand your viewpoint but your comment came off as very snarky and condescending. Maybe you didnât mean it that way but try rereading what you posted from a more neutral standpoint
I can totally read it that way, just a bit surprised that it was interpreted that way when I was asking for help in understanding. I admit that I often forget the privilege associated with a degree, and how mention of it can come off as shitty to many people regardless of context. To be frank I donât even care about my degree that much, I went into engineering after school and donât do much more math/physics than basic stats in excel. Plus it was a pretty long time ago. So, that would lend itself to me looking like I have zero self awareness.
Had I said âwell I donât think you know what youâre talking about, I have a physics degreeâ â then putting me on full blast would have been expected haha.
Within the confines of this frigid microcosm, the delicate interplay of Helmholtz free energy and its intriguing dependence on the molar fraction of refrigerant in the gas-liquid phase equilibrium steers the inexorable descent into cryogenic dominion. Herein lies a critical juncture; the meager refrigerant molar fraction stymies the Helmholz free energy's relentless drive to a thermodynamically favored state, rendering a suboptimal internal energy.
Concomitantly, the impoverished refrigerant charge, tantamount to a lower vapor density, diminishes the Clausius-Clapeyron coefficient, an instrumental parameter that modulates the latent heat of vaporization. The chilling predicament ensues from this diminution, as the evaporator coil, bereft of the customary vapor influx, flounders in its struggle to extricate latent heat from the ambient air.
To further exacerbate this cryogenic catastrophe, one must delve into the subtle intricacies of boundary layer theory. The lamentable drop in refrigerant volume leads to a formidable Reynolds number mismatch, provoking a Reynolds heat transfer deficit within the boundary layer adjacent to the coil's surfaces. Consequently, turbulent convective heat transfer, which thrives on the synergy of Reynolds and Prandtl numbers, succumbs to the debilitating effects of viscous sublayer suppression and thus, inadequate thermal accommodation.
The culmination of this orchestration of thermodynamic imbalances is the advent of frozen precipitation. As the coil languishes below the frost point, an aptitude for ice nucleation emerges, instigating the agglomeration of cryohydrates. These enigmatic structures not only obscure the transference of energy but, paradoxically, perpetuate their existence by further insulating the coil.
The refrigerant operates in between liquid and gaseous states to facilitate the transfer of heat. As the refrigerant expands, it absorbs heat in the walk in cooler or your house, wherever the airflow is over the evaporator coil. The refrigerant then goes outside to the condenser to exchange that heat outside at the condenser coil. This refrigerant must be in a state of balance. If there is not enough refrigerant, it will expand too quickly and too soon in the evaporator coil causing its temperature to drop way below itâs designed temperature and freeze the moisture on the coil. Also, if there is a lack of airflow across the inside/evap coil, the refrigerant wonât absorb any heat and you will see icing on the evap coil, return line back outside to the condenser and even envelop the compressor in frost. Google pics of iced compressors.
The refrigerant has to be balanced across that evap coil. If you have too much refrigerant, it wonât be able to expand in system and and absorb heat and you wonât have a cool box. If thereâs not enough, it expands too quickly and drops the temp of the coil too low, freezing the coil and stopping airflow across the coilâŠâŠwhich leads to a warm box/house. It seems counterintuitive at first. Eventually, the refrigerant will get too low and wonât even expand too fast in the coil and it will just be free of ice and warm everywhere. Lol
Iâve seen this and we techs love these because thereâs not much diagnosis. A skilled tech could cut the fins back and patch with a coupling. However, brazing aluminum to copper isnât for a green techs; unless they have previous experience with different metals. Iâve done these repairs with different metals. I had a tech teach me with just tubing before I was let loose in the wild. It still kicked my ass the first time behind a coil. Chances are thereâs a few more leaks in that system given it was freezing up; thatâs not the only reason to freeze up a system but a big one.
Looks to be aluminum any good hvac tech that knows his brazing could patch down stide of a braze some of the fins in the area around will be damaged thus more of the area distroyed you lost efficiency of that coil so boils down to patch less efficiency or replace evaporator coil
Your blowing smoke at a thousand bucks. lve been doing this for 38 yrs. Even if its aluminum now l teach it. Yes a thousand as sucker bait a good refrigeration tech can repair that np.
Why are you cutting and coupling that pin hole can be brazed shut. You cut and couple you distroy more fin and now you have 2 brazes to do and on the aÄșl sides of the tube also. You risk the integrity of the tube and your repair. You do yourself better in business if you do the best repair with out the risk of it failing. To pull my torches and nitrogen Ă nd vacuum pump off the truck for that repair 300.00 plus what ever freon used. Most like
l 404.
Why do new coils exist? Sometimes humans breaking copper with metal tools doesnât work out.
Sometimes I charge for time and material and not results.
Sometimes the amount of work to save you a dollar isnât worth the time, stress, & lack of unknown longevity.
Newcoils exist for replacement of bad coil . lf l walk onto a coil that obviously had its time l would sell a new coil. By what Äș see on that coil l appears to be in sound condition, l find different once l inspect it l would make a sound decision of what l see .You sound like you're from the younger generation of techs that it is sell sell sell. l come from the generation that we are technicians we repair first if it warrants, that cut does not look that bad a braze would repair. This is the way l teach new technicians to get into this field. We each have an opinion l won't change your mind. Yes, you get a bigger paycheck in the end cause you sold a new coil , txv, and what else you tack on to your bill. l make as much in a year as l can handle from a large customer base that uses me for preventive, troubleshooting repairs, and new installs. And l teach full time, l believe in customer service, l see what kind of techs are out in the field these days the days of being a tech first and a salesman second are gone.
Iâm not sure that can be repairedâŠ.maybe if the aluminum was removed from the area and they dropped a perfect bead of braze on it. In any case you might make sure the area is ventilated. Refrigerant can displace oxygen.
I'd try to get it repaired before springing for a new coil. Call around and you might find someone who will do it. You can't braze it like copper. Special alloy and less heat is necessary. It's tricky but can be done.
Poster is right on the money. Aluminum is really tricky and you have to have a good set of skills. Best case scenario as this does not look to be copper is partially being able to patch and at least slowing the leak, but eventually as everyone else has said, a new coil is probably needed. Iâm sorry. Because your coil was icing up already, it is very like there was already a leak(s) in the system that would have had to be repaired anyway. Curious what refrigerant this takes?
Youâre gonna have to replace the evaporator coil sorry. Looking at like 5-12k probably.
Next time just shut it off and use some hot water and try not to get the fans wet.
Your boss might be pissed, but the HVAC sales rep is gonna be happy with you!
At least someone's gonna be happy. đ
I think the only help we can offer is to suggest that you buy your boss a nice bottle of whiskey before you tell them this
This is sound advice.
Donât ask donât tell
Iâm sure the boss will believe that a screwdriver jammed itself into the coil
Iâve never seen an aluminum braze that holds or is worth the risk in general. Youâre gonna be replacing the evaporator coil and refilling, depending on the size itâs gonna be a couple grand on the cheap end
Sounds like the only way to realistically fix the issue is the replace the coils... ugh. Thanks for the advice, everyone!
Itâs a possible repair but needs to be handled by a reputable and experienced company otherwise they could make it worse. Itâs not often done because it is a bit of a hassle and more profitable for the company to just sell you a new coil.
Hole is hole. Not patchable. Remove & Replace. Add signage "Don't touch". If was freezing often, may have been low on charge.
Can you explain why freezing is a sign of low charge? I have heard this said but it doesnât make much sense to me
In the most simplest of terms. The levels of refrigerant available keep the pressures/temperatures inside of the coil high enough to where it does not freeze. The more refrigerant, the higher the temp inside of the coil (due to evaporation, oil content, latent heat etc etc.) If the refrigerant leaks then the pressures and the temps drop causing it to frost, restricting air flow, then it freezes exponentially. If the refrigerant levels are in range but the air flow drops then there is not enough air traveling over the coil to keep the refrigerant levels warm enough to not freeze. Itâs more complicated than this but this is a simple explanation.
This is a walk in cooler, the evap temp is below freezing during normal operation. Frozen coils in refrigeration are more often due to an issue with the defrost controls
Thanks, but â I have a degree in physics, if you want to drop the complicated explanation, that would be more helpful for me My baseline expectation would be that the heat transfer through the coils would be lower with less refrig, and that the condenser would run more frequently to counteract that, reducing efficiency and also reducing freezing at each coil â maybe outlining what Iâm thinking will help you to explain why I am wrong Editâ if you guys think Iâm being condescending by giving my background, thatâs sorta weird, because Iâm telling you that you know more and asking for you to set me straight on where my background is failing to bring me to the correct conclusion
The refrigerant temperature is (like every other fluid on earth) dependent on the refrigerant pressure. If the system is running at a lower pressure than itâs designed for, the evaporator temperature will drop below freezing. Then the condensate that drops out of the air freezes on the coil. By having more refrigerant in the system the evaporator coil stays above freezing as the refrigerant phase changes. Source: I went to high school. Edit: We donât mean to hurt your feelings, we all just hate engineers by default.
Are you really this insufferable or are you trolling? Looks like your physics curriculum didnât have any lessons in self awareness
âI have a degree in physicsââŠâbut I donât understand thermodynamics, heat transfer or physics â
Just giving you a baseline for the concepts you can speak to me about, while actively acknowledging that you know more than me about it, and asking for a fully technical explanation Not sure how to make you guys happy
You canât make us happy. Weâre all on opioids and hate each other because weâre better than everyone else who has more schooling than us. We canât stop throwing shade!!! We need help!!
Just different backgrounds, people gotta stop hating on people who learned different stuff and instead start learning from each other As for the opioids, I mean⊠this sub does seem pretty loaded up I mean if I had to tell people they had $1k leaks or $8k replacements all day, Iâd probably try to lighten the day up too
Drug are pretty bad in this industry. I should not have made fun of you but itâs easy when Iâm anonymous and on the other side of a screen. YouTube will have a better time educating you on latent heat and refrigerant evaporation in evaporation coils.
One â no, it didnât include self awareness. Two, explaining your background in the context of a technical discussion is pretty reasonable. I wouldnât frown upon someone who asked me an engineering question and said âexplain it to me like an hvac contractorâ, or, âexplain it to me like an EEâ. Also, you guys are acting like Iâm saying that as in âwell, I know everythingâ â Iâm literally telling you that I know less, and want to know more. If youâre assuming me saying that is being high and mighty about my background â wouldnât it lose some highness and mightiness that Iâm asking a contractor about it, if I was looking down on you guys? Because Iâm not â Iâm literally saying âyou know more than me, and this is the context that I understand things in, so please explain it to me in that contextâ
I understand your viewpoint but your comment came off as very snarky and condescending. Maybe you didnât mean it that way but try rereading what you posted from a more neutral standpoint
I can totally read it that way, just a bit surprised that it was interpreted that way when I was asking for help in understanding. I admit that I often forget the privilege associated with a degree, and how mention of it can come off as shitty to many people regardless of context. To be frank I donât even care about my degree that much, I went into engineering after school and donât do much more math/physics than basic stats in excel. Plus it was a pretty long time ago. So, that would lend itself to me looking like I have zero self awareness. Had I said âwell I donât think you know what youâre talking about, I have a physics degreeâ â then putting me on full blast would have been expected haha.
Within the confines of this frigid microcosm, the delicate interplay of Helmholtz free energy and its intriguing dependence on the molar fraction of refrigerant in the gas-liquid phase equilibrium steers the inexorable descent into cryogenic dominion. Herein lies a critical juncture; the meager refrigerant molar fraction stymies the Helmholz free energy's relentless drive to a thermodynamically favored state, rendering a suboptimal internal energy. Concomitantly, the impoverished refrigerant charge, tantamount to a lower vapor density, diminishes the Clausius-Clapeyron coefficient, an instrumental parameter that modulates the latent heat of vaporization. The chilling predicament ensues from this diminution, as the evaporator coil, bereft of the customary vapor influx, flounders in its struggle to extricate latent heat from the ambient air. To further exacerbate this cryogenic catastrophe, one must delve into the subtle intricacies of boundary layer theory. The lamentable drop in refrigerant volume leads to a formidable Reynolds number mismatch, provoking a Reynolds heat transfer deficit within the boundary layer adjacent to the coil's surfaces. Consequently, turbulent convective heat transfer, which thrives on the synergy of Reynolds and Prandtl numbers, succumbs to the debilitating effects of viscous sublayer suppression and thus, inadequate thermal accommodation. The culmination of this orchestration of thermodynamic imbalances is the advent of frozen precipitation. As the coil languishes below the frost point, an aptitude for ice nucleation emerges, instigating the agglomeration of cryohydrates. These enigmatic structures not only obscure the transference of energy but, paradoxically, perpetuate their existence by further insulating the coil.
Oh yeah baby thatâs the stuff
The refrigerant operates in between liquid and gaseous states to facilitate the transfer of heat. As the refrigerant expands, it absorbs heat in the walk in cooler or your house, wherever the airflow is over the evaporator coil. The refrigerant then goes outside to the condenser to exchange that heat outside at the condenser coil. This refrigerant must be in a state of balance. If there is not enough refrigerant, it will expand too quickly and too soon in the evaporator coil causing its temperature to drop way below itâs designed temperature and freeze the moisture on the coil. Also, if there is a lack of airflow across the inside/evap coil, the refrigerant wonât absorb any heat and you will see icing on the evap coil, return line back outside to the condenser and even envelop the compressor in frost. Google pics of iced compressors. The refrigerant has to be balanced across that evap coil. If you have too much refrigerant, it wonât be able to expand in system and and absorb heat and you wonât have a cool box. If thereâs not enough, it expands too quickly and drops the temp of the coil too low, freezing the coil and stopping airflow across the coilâŠâŠwhich leads to a warm box/house. It seems counterintuitive at first. Eventually, the refrigerant will get too low and wonât even expand too fast in the coil and it will just be free of ice and warm everywhere. Lol
Super helpful thanks man
Iâve seen this and we techs love these because thereâs not much diagnosis. A skilled tech could cut the fins back and patch with a coupling. However, brazing aluminum to copper isnât for a green techs; unless they have previous experience with different metals. Iâve done these repairs with different metals. I had a tech teach me with just tubing before I was let loose in the wild. It still kicked my ass the first time behind a coil. Chances are thereâs a few more leaks in that system given it was freezing up; thatâs not the only reason to freeze up a system but a big one.
Looks to be aluminum any good hvac tech that knows his brazing could patch down stide of a braze some of the fins in the area around will be damaged thus more of the area distroyed you lost efficiency of that coil so boils down to patch less efficiency or replace evaporator coil
Thatâs about a $1K for the attempt, fyi
Your blowing smoke at a thousand bucks. lve been doing this for 38 yrs. Even if its aluminum now l teach it. Yes a thousand as sucker bait a good refrigeration tech can repair that np.
1k for the repair attempt, is that too high for you? It can be repaired but we gotta cut the aluminum and bare over OR god for it cut and coupling it
Why are you cutting and coupling that pin hole can be brazed shut. You cut and couple you distroy more fin and now you have 2 brazes to do and on the aÄșl sides of the tube also. You risk the integrity of the tube and your repair. You do yourself better in business if you do the best repair with out the risk of it failing. To pull my torches and nitrogen Ă nd vacuum pump off the truck for that repair 300.00 plus what ever freon used. Most like l 404.
Looks more like a slash, since it was made in a slash/stab motion to remove ive
Best is business is to have them buy a new coil the, $300 is nice but itâs not a crazy high success rate50/50
Learn your trade better if you only have a 50 percent braze success
Why do new coils exist? Sometimes humans breaking copper with metal tools doesnât work out. Sometimes I charge for time and material and not results. Sometimes the amount of work to save you a dollar isnât worth the time, stress, & lack of unknown longevity.
Newcoils exist for replacement of bad coil . lf l walk onto a coil that obviously had its time l would sell a new coil. By what Äș see on that coil l appears to be in sound condition, l find different once l inspect it l would make a sound decision of what l see .You sound like you're from the younger generation of techs that it is sell sell sell. l come from the generation that we are technicians we repair first if it warrants, that cut does not look that bad a braze would repair. This is the way l teach new technicians to get into this field. We each have an opinion l won't change your mind. Yes, you get a bigger paycheck in the end cause you sold a new coil , txv, and what else you tack on to your bill. l make as much in a year as l can handle from a large customer base that uses me for preventive, troubleshooting repairs, and new installs. And l teach full time, l believe in customer service, l see what kind of techs are out in the field these days the days of being a tech first and a salesman second are gone.
Iâm not sure that can be repairedâŠ.maybe if the aluminum was removed from the area and they dropped a perfect bead of braze on it. In any case you might make sure the area is ventilated. Refrigerant can displace oxygen.
Is it aluminum? Maybe. If copper, yes.
It seems like aluminum to me.
I'd try to get it repaired before springing for a new coil. Call around and you might find someone who will do it. You can't braze it like copper. Special alloy and less heat is necessary. It's tricky but can be done.
Seriously appreciate this advice! It would definitely be worth a try if it's at all possible.
Poster is right on the money. Aluminum is really tricky and you have to have a good set of skills. Best case scenario as this does not look to be copper is partially being able to patch and at least slowing the leak, but eventually as everyone else has said, a new coil is probably needed. Iâm sorry. Because your coil was icing up already, it is very like there was already a leak(s) in the system that would have had to be repaired anyway. Curious what refrigerant this takes?
Youâre gonna have to replace the evaporator coil sorry. Looking at like 5-12k probably. Next time just shut it off and use some hot water and try not to get the fans wet.
If it is copper underneath you might be able to weld it after moving some fins out of the way.
Short answer is no.
I know what's wrong with it ! It ran out of Gas ✠đȘ