Tech Tip Refrigerant Charge Level

This describes the refrigerant process in a capillary tube (cap tube) system, and how to determine the correct charge level by the Frost Line method. The video shows an example of a correctly charged system plus how to identify overcharge and undercharge conditions.

[@patrickpk6299]

best video on the topic! i've watched many today haha! THANKS!

[@AAAA-oe4ii]

This should at least have a million views Never seen such a simple explanation.

[@CoastalClimate]

Thanks AA. It really is a very simple process, but the techs want to turn into something highly technical that they perceive only they can understand.

@@CoastalClimate I think you are suffering from Donner-Kruger effect. images.app.goo.gl/eAZcprz6Lf393fdDA

[@adeyemibabatunde1814]

@@CoastalClimate Thanks immensely Can undercharging also causes freezing of suctIon pipe(pipe from evaporator to compressor) similar to overcharging. There are several information and experience which state that undercharging causes freezing of suctIon pipe also. Kindly differentiate freezing of suctIon pipe between under- and overcharging

[@coastalclimatecontrol]

@@adeyemibabatunde1814 - Thanks for watching. No, a undercharged state should not cause freezing of suction line anywhere near the compressor. Maybe the information you came across is referring to something else or misunderstood.

[@adeyemibabatunde1814]

@@coastalclimatecontrol Thanks for always being helpful and prompt. There are several information/videos online which stated that undecharging or low refrigerant also causes ice on evaporator coils and suctIon pipe. This should be corrected. Some technicians/ artizans may want to collect money from customers, It might just be dirty evaporator coil/ filter causing ice which require cleaning

[@will_doherty]

Perfectly described, illustrated, and presented - thanks for sharing your expertise.

[@MustadMarine]

Excellent tips, thanks. 5 minutes well spent.

[@coastalclimatecontrol]

Glad it was helpful!

[@kameltoes2625]

Actually this compressor is readily available in the US, it is sold by various resellers of fridge units under their own names, but in the end it is a Danfoss 35 compressor. I have this unit on my boat for the ice box..

[@JohnnyLawBMC]

Very nicely done. Your demonstrations are perfect Thank you so much for sharing

[@coastalclimatecontrol]

Thank you, John, it is our pleasure to share.

[@pauladams8562]

Thanks. I have wrestling with the correct amount of charge for two days that has got to be the simplest and best explanation I have heard No pressures no weights. Either you have frost or not.

[@johnmoore3859]

Excellent and clear explanation. Really helpful. Thanks for taking the time to make the video.

[@dannyjensen4954]

Best video I have ever seen on this topic. I can now move forward to get correct charging. Thanks.

[@yxcvmk]

Wow, what a great Video. First a thumbs up. Hope this Video will be seen by millions in the future! In my fridge, I can not access the evaporator inside. (Waeco with the kind of Compressor you use here). I wonder if the refrigerant level is low, seems to cool OK, but is working long. I can only access the return tube (low side) to the compressor, which is not at all iced up, indicating either good or low charge if I did understand you correct. The question is, can the temperature of the return tube (maybe in relation to environment or fridge temperature) give an indication if refrigerant is correct or low? I also wonder what a "professional homeowner" (term stolen from Wranglerstar) must build to be able to evacuate a refrigerant system into a tank and use it for filling it up again, after vacuum, and maybe a nitrogen flush, or can the "professional homeowner" flush by other means? Maybe you/anybody can point me in the right direction?

[@verohandymike]

Very good informative video, shows how one may evaluate charge levels visually. Obvious this took time and effort.

[@richardgraham3658]

Great video I thought the gurgling noise was a problem LOL

[@jeffcee9457]

Very helpful thanks

[@billbailey48]

Excellent video, professional information, thank you very much!

[@wasimedoo7994]

Very good information bro 👍

[@taiwanluthiers]

I found one real symptom of undercharged system is that the compressor overheats, seriously. I think it's because in a properly charged system there's still a little bit of heat the refrigerant has yet to absorb, and it cools the compressor going in, however without enough refrigerant, the refrigerant isn't absorbing anything, and therefore the compressor will get HOT to the touch after it runs for a few minutes, until the thermal protection kicks in and shuts the compressor off (usually it's a reed switch stuck to the compressor that opens the circuit when it gets too hot). If your compressor is shutting down prematurely for no reason, this is why.

[@adeyemibabatunde1814]

Thanks

[@markg6860]

A very informative video! Can you advise what changes (if any) to expect to see/hear when the fridge/freezer is in the automatic defrost cycle? Also, whenever my freezer kicks back on for another cooling cycle, a light frosting forms on the section line almost back to the compressor, but then it quickly thaws in a distinct line back to the freezer's evaporator. Does that mean the appliance is slightly overcharged? (Both fridge and freezer appear to be operating correctly ... 0F in freezer and 40F in fridge), with the temperature controls both set at 0/normal. Many thanks!

[@souklasackthongsavanh9845]

Excellent demonstration...thank you

[@muhammadjaved3430]

Very thanks excellent video

[@dand1486]

ice or frost doesnt always mean its flooding back but the temp is lower than the dew point temp, but yes, oddly cap tube systems will usually frost when flooding back. best way is to use ur pt chart , check ur super heats near compressor, than u know 100%... good video tho.

Well said! This is beer can method, and today, with digital gages availiability and price there, it is obsolete and inacurate practice for refrigeration tehnician!

[@adeyemibabatunde1814]

Thanks immensely Can undercharging also causes freezing of suctIon pipe(pipe from evaporator to compressor)similar to overcharging. There are several information and experience which state that undercharging causes freezing of suctIon pipe also. Kindly differentiate freezing of suctIon pipe between under- and overcharging

[@johngorden5810]

Thank you this video help me out a lot

[@MrHorsenaround]

Nicely done. Thank you!

[@Yachtibis]

Thanks for this video - we're in the Caribbean and we have inherited a boat with a Frigoboat AV 35 F unit and flat evaporator panel. It's not been used in a couple of years at least, but its showing signs of having no gas - the compressor starts normally but there is no heat build up anywhere in either the compressor or the capillary tubes, and there's no heat differential anywhere in the system. I'm having difficulty identifying which of the two capped off outlets is the one to use to measure low side pressure and to add gas... can you give me any guidance? thanks!

[@jackboltsvolts8986]

The Low Side (cold) is the bigger pipe, the High Side (hot) is the smaller pipe. The pressure depends on the refrigerant used. Example: R-134a, with the compressor NOT RUNNING, around +5 PSI, with compressor RUNNING the pressure should be a little above Zero PSI. More than +2 PSI, might get frost on the return line (low side), meaning there is refrigerant in excess. More about... if the pressure is bellow Zero (vacuum) with the compressor "not running", it is low on refrigerant... if the pressure is bellow Zero with the compressor "running", it might be cooling but not enough, so it just needs to be added a little refrigerant. If you have a different type of refrigerant do your home work... R600a works with negative pressure... erhrrrr... Good luck!

[@hulubanadrian1623]

What's the max length in centimeters of tubing from compressor to fridge to be efficient? Thanks

[@petunialinton520]

You just fix my problem

[@whitesheatingairappliancer7101]

What's the name for the refrigerant silver couplings?

[@willarddevoe5893]

What happens if you install A a compressor too small or B a compressor too big ?

[@CoastalClimate]

Too small: it may not do the job at hand. Too big: you may pay too much in energy and component cost in relation to that job at hand.

[@beatbox2250]

I overcharged my fridge. How do I reduce the refrigerant Ive put in? Please help me. Frost is in the suction line to my compressor

[@japerolthuis]

Do not tell EPA, but vent Some off

[@markg6860]

Turn the fridge off, then vent from the port where you added the R134a. Don't do it while the fridge is running, or it will just suck air into the system, which is not good!