HVAC 093 Flash gas revisited with a deeper view

[@horsth9566]

An amazing and educational presentation. I love it. Thank you Ty.

[@hubercats]

I’ve always found that developing intuition as to how things work is very helpful in diagnosing problems. This video is a great example of such. Thanks again, Ty! - Best - Jim

[@love2hvac]

I agree. If you know how something works, you can fix it or make it better.

[@paulthompson1654]

hi Exactly the reason why I fit second condensers in all things mobile industry to ensure low temperature /pressure 100 % liquid supply to evaporator . If liquid line passes engine compartment always insulate. Always had great success doing this . Thankyou for educating me on the theory.

[@xelaju8]

Great video. Very detailed info about flash gas and efficiency.

[@jkbrown5496]

This is what I like, there's always just a little bit more to learn. Subtleties and edge cases. Thinking about them improves your overall understanding. But when you first start out learning, you have to get the big picture with simplifying assumptions first. Like learning about electricity, where in most cases and when you start out there is the simplifying assumption that the wires have no resistance. But then you get confused as to why there is 240vac at the transformer but the motor you are installing is rated for 230vac. That's because the motor is optimized taking into account the the allowable 5% voltage drop across the feeder and branch circuit wiring. Get the wires long enough or use high enough frequency and the wires start to matter.

[@borshardsd]

You're the man Ty

[@rpsmith]

Excellent presentation! Thanks!

[@love2hvac]

Thank you

[@SpinStar1956]

Ty, Really great deep-dive. I’ve wondered why the don’t use a water-spray on the condenser like an evaporative cooler. If you misted the condenser, I wouldn’t think you’d use very much water and would save electricity ⚡️

[@shrededpudding5921]

they do make kits for that. Ive only seen it once where the only possible location for the condenser was a non optimal location that was resulting in way higher temperatures. sadly the mist was not helping very much.

[@realestateservicessaleshea99]

Again I really appreciate the time and effort it takes you to prepare these videos, always insightful! Pierce Phelps (carrier) taught,the subcool readings are to be taken as close to the metering device as possible,sight glass & drier also inside. I think I'm going to throw out my air-conditioning/ refrigeration toolbox manual by David Tenenbaum.😂🤣😂🤣🤣🤔 🍺🍺🍺🥃🥃🍿🏌🏻‍♀️ Stay safe. Retired (werk'n) keyboard super tech. Wear your safety glasses.

[@love2hvac]

Thank you.

[@m.b.1716]

If I heard correctly, you mentioned that it was possible to divert the refrigerant after the Receiver back through the condenser area on a secondary loop. How does this differ just from making the primary condenser loop longer? I take it that part of the design challenge of a AC unit is to set the condensing unit coil length to match expected and average environmental conditions of where the unit is placed. Sometimes, however, expected and average conditions do not always match. To solve this problem are there designs that somehow divert liquid line flow until the optimal sub cooling temp is reached?

[@love2hvac]

Great question. It means your thinking. Having a larger primary could may sub cool the refergerant but once the liquid flowed into the receiver tank, it would be back at saturation (liquid and vapor) leaving it would be a solid colum of liquid but still at saturation. By having the refergerant leave the reciver as a saturated liquid, then onto the condensor again we can cool the refergerant even more, subcooling it below saturation. This ensures we have a solid colum of refergerant. Take a look at the reciver video and it may help understand. As for controls we have controls that bypass the condensing coil in low ambient.

[@samersarah957]

Hello Mr.Ty let to say insert liquid line through suction line do you think it’s will be enough to sub cool liquid? Thanks.🌷

[@love2hvac]

It would subcool the refrigerant on the high side and superheat the vapor on the suction side. You see this sometimes on refrigerators where they solder the liquid and suction line together as a heat exchanger.

[@fabiodarocha2842]

Ty. Is is possible that a system that had a leak through both shrader core valve ,still have refrigerant in the system in the form of liquid? The leaking occurred while the unit was off . It was added about a pound of refrigerant the day before.Piston type unit,R22 refrigerant. Superheat was done properly while weighing in refrigerant . The leaking wasn’t caught because it had shrader core removal tool on low and high side of the unit.

[@love2hvac]

absolutely possible. Its a god habit to use new cores anytime you use the core removal tool. They are cheap

[@joshh6104]

Ok I need to talk through this to make sure I understand... after going through the condenser the refrigerant is 100% liquid at the service port, so pressure no longer can be converted to temperature, so... the guage reads say, 250psi, but the temperature of the line at the port is lower than the p/t chart temp because it's all liquid but that liquid still has the pressure of the vapor behind it, which is why my gauge still reads 250psi? So if I poured ice water on the condenser, I would cool the part of the condenser off that was at saturation, thus lowering the pressure, giving a lower differential at the evaporator and feeding less refrigerant through the metering device, but if I waited until it was 100% liquid and subcooled it with ice water I would just be cooling down the liquid and keeping the same pressure?

[@love2hvac]

Yes that's correct

[@joshh6104]

@@love2hvac awesome! Thanks for all these videos. They are life saving!

[@toyinorodare4072]

Thank You A lot for this information. However for a Commercial system with Long Run pipe and lot of pressure drop in the line, can a smaller condensing units be install with a plate heat exchanger so that the liquid can be sub-cool to around 60°F if the Refrigerant boil at around 40°F in order to increased the Refrigerating effect?

[@love2hvac]

Yes

[@shifter8207]

Would your suction pressure change based on how much flash gas you had or not really

[@love2hvac]

That is a great question. In short no. But since your thinking about it there are many things affecting the auctions pressure such as the liquid pressure entering the metering device, the air temp and humidity (or product temp) on the coil the air speed, the size of the coil and how much refregerant is flowing in the coil. Overall they all equal out to 1 suction pressure. If we change any 1 aspect of that we get a new suction pressure. Overall the suction pressure after 15 minutes of run time balance out and it dose not fluctuate much.

[@shifter8207]

@@love2hvac thank you!