HVAC 103 Scenario Dirty Condensing coil

[@kidpont7648]

Ty great presentation as usual you’re probably one of the few that covers operation with orifice of which there are still plenty of systems still out there with them. Please keep up the wonderful work you do teaching your desperately need it out there thanks.

[@racegrubb2152]

I was at one another tech condemned an indoor txv, low suctuion, high superheat, i rechecked before i pumped down, had 13 degress subcooling, looked fine, except condenser coil was dirty, i cleaned it, let it run 20 minutes, now only had 1 degree subcooling, added 2.5 lbs, got subcool at 8, superheat at 14, did leak search, indoor coil leaking, glad i checked 1st, just make sure you look at the condenser coil, before condemning a txv, could be low charge with dirty outdoor coil making it look fully charged because subcooling looks normal. Love these videos, nice refresher

[@love2hvac]

Yes! That's great! My friend Chris calls it big picture diagnostics! Well done!

[@zafirkhan979]

Just wow...you are a great teacher...

[@edwardgarza5104]

Dirty condenser would show us hi subcooling and keep the superheat at the appropriate amount?

[@rogerbettencourt9654]

I can’t wait to see your WeTube editing and graphics catch up to your knowledge, which will happen, thanks again Ty.

[@AngelRodriguez-qg5zq]

Excellent video Ty, I was wondering if you could explain in more detail what you mentioned at minute 1:48? It is the part where you talk about how the increase in the temperature of the air around the condenser increases the pressure inside the condenser. Greetings

[@honestman276]

Thanks from Bangladesh.

[@JohnnyJr396]

I know you said it but to make sure I have it.So a txv with a dirty condenser will back refrigerant up in the condenser. The suction pressure will still be LOW / NORMAL and maintain superheat . Is the high side trying to push so much gas in to the evap that the txv is trying to slow it down and cooling isn’t affected? I always thought the cooling capacity of the evap was dropped too. I’ve seen low charge with dirty condenser give normal suction and head pressure till outside coil was cleaned

[@love2hvac]

Yes but don't look at pressures! Superheat and subcooling will tell you what's happening. The TXV will try to maintain superheat depending on how bad it is. The cooling capacity will drop. Also the liquid line will exert an opening force on the TXV,. So if the condensor is really dirty it will push the TXV open.

[@JohnnyJr396]

@@love2hvac and suction pressure will be normal? Thanks Ty you are awsome!

[@love2hvac]

There is no such thing as normal suction pressure. TXV has no way of controlling suction pressure. Pressure changes with temperature, humidity and airflow. If you have a tire look at pressure, if you have an HVAC unit look at superheat and subcooling

[@JohnnyJr396]

@@love2hvac mind blown indeed! I’ve never thought of it that way. Always looked at what typical coil temps operate at. High temp 40 , coolers around 20, freezer 0 down to low temp. Thanks Ty I enjoy learning something new every day!

[@martingates6501]

Need help Mr. Branaman If I have to make an evaporador coil for a 10 ton condenser unit to cool the water in a tank, how many feet of pipe do I need, how do you calculate?

[@love2hvac]

That exceeds my knowledge. That falls into engineering

[@love2hvac]

sciencing.com/uses-temperature-sensor-5997997.html

[@love2hvac]

www.engineeringtoolbox.com/heat-condenser-evaporator-d_881.html

[@andyreyes6464]

Excelente video

[@averyalexander2303]

Nice video, but I have never seen a system's capacity increase from less airflow through the condenser in normal weather people would be using their AC in. For that to be possible, I'd think the outdoor temperature would have to be quite low. Then it's definitely possible. After all, there is a reason why we have various head pressure control devices for systems that are run in cold weather.

[@love2hvac]

I never said the capacity would go up

[@averyalexander2303]

@@love2hvac At 5:00, you said it's possible for the evaporator's delta T (temperature differential) to increase, meaning a larger temperature difference between the return air and the supply air. Did I misunderstand what you intended to communicate? Assuming the evaporator airflow remains constant (which it would if condenser airflow is the only variable), a higher temperature drop across the evaporator would mean a higher capacity (more BTUs of heat removed per hour of runtime).

[@love2hvac]

@averyalexander2303 That DOES NOT mean an increase in capacity. When the suction pressure rises you loose dehumidification transferring laten removal to sensible removal. DELTA T IS NOT CAPACITY. !!!! To calculate capacity you need the specific information of the compressor performance chart with superheat subcooling suction saturated and liquid saturated. To differentiate capacity of the evaporator you need the exact CFM, return air wet bulb and supply air wet bulb

[@averyalexander2303]

@@love2hvac Great point, thanks for correcting me! A higher delta T with the same evaporator airflow, humidity, etc would mean a higher sensible capacity, but as you said, latent capacity depends on humidity removal and total capacity is latent + sensible capacity. Same thing can happen with too much airflow through the evaporator since a warmer coil condenses less moisture. I'm curious under what conditions you have seen the evaporator delta T increase with less airflow through the condenser though?

[@love2hvac]

@averyalexander2303 With a fixed orifice metering device, When the head pressure rises, there is more vapor pressure pushing against the liquid column. That means more liquid is pushed into the evaporator coil but also raises the suction pressure. This reduces laten heat removal and increases sensible heat removal. You also have more liquid to boil away to a vapor. This was expanded in previous videos and demonstrated. If you look at a target superheat chart, you will see it. You can compare conditions and completely flood the evaporator coil under one set of conditions and completely starve the evaporator coil under another. Just because you flood the evaporator coil does not mean that it is system capacity. The compressor still has to move the refrigerant and is suspectable to the compression ratio. All the heat has to be rejected in the same space meaning higher head pressure. You will eventually reach a point where all the liquid is pushed out of the condensor and you are pushing liquid and vapor into the metering device. The videos are in order to explain this. Jumping to the end of the videos means a lot of misunderstandings and confusion. This is the reason they are in order. One lesson builds for the next and so on.

[@MichaelHernandez-lc2wb]

Greetings from FL. Your handwriting is terrible but your teachings are great. Thank you Ty :-)

[@rogerbettencourt9654]

Michael Hernandez, my handwriting is far worse, my teaching skills are ok, however my knowledge, especially compared with Ty, is terrible. Lol

[@love2hvac]

My handwriting is terrible and my spelling is worse. Lol. One day I will get to graphics.

[@love2hvac]

What makes a good teacher is #1 caring, #2 willing to learn. You are here so that shows you probably have both. That makes you a good teacher. I recorded some teacher segment tips. I'm debating on where to publish them.

[@realestateservicessaleshea99]

Thanks ! I think your indoor blower is to small ,and your condenser fan is upside-down! 🤣😅😅🤣 🥃🥃🍺🍺🍺🍿🏌🏻‍♀️ Stay safe. Retired (werk'n) keyboard super tech. Wear your safety glasses!

[@Gary-ts6dh]

3:14 - 3:23 "not alwasy"?

[@love2hvac]

There is a point where the head pressure will force the TXV to open. There will be a point the compressor floating seal for scroll will relieve or the internal pressure relief valve will open. There is also a point where the condenser can't reject enough heat to condenser to a liquid. Under those scenarios the schooling would not build up.