How to determine the amount of refrigerant charged in a system?

[frank721]

Dear friends, i am a freshman in this area. Thanks for all guys helping me before in this forum.

Now, i have a question. i bought a L'UNITE HERMETIQUE (FH4518Y) refrigeration unit. There is a oil separator after compressor and accumulator before compressor. The medium is R134a. i want keep the evaporator temperature at about 20 to 25 degree C.

How can i determine the amount of R134a charged in this system? Any corrolation is useful?

Thanks a lot.

[Peter_1]

Till your SH becomes within the desired range, +/- 5 to 7 K.
Or a full sightglass if fitted.

[Yuri B.]

Has the seller said you the unit is filled with R134 - not with nitrogen ?

[Magoo]

What is this, trade training by remote control ?.
magoo

[abdulazman]

hi ya frank,

Can't help much, dunno whether this chart will help you
Good luck dude

[frank721]

Has the seller said you the unit is filled with R134 - not with nitrogen ?

yes, i am sure it's worked with R134a

[frank721]

Till your SH becomes within the desired range, +/- 5 to 7 K.
Or a full sightglass if fitted.

thanks, can i say the amount of refrigerant charged could be determined through gradual charging test?

[frank721]

What is this, trade training by remote control ?.
magoo

thanks for ur reply. but i dun know what ur point may be.

[frank721]

hi ya frank,

Can't help much, dunno whether this chart will help you
Good luck dude

Thanks a lot. i'll read it carefully

[Yuri B.]

Hi Frank. Thank you for the inadvertent bit of "trade training", now I know FH4518Ys and the like ones ref. units are being sold pre-filled with the charge of the corresponding refrigerant - simply like ACs are.

[frank721]

Hi Frank. Thank you for the inadvertent bit of "trade training", now I know FH4518Ys and the like ones ref. units are being sold pre-filled with the charge of the corresponding refrigerant - simply like ACs are.

I just discharged my system then want to know how much refrigerant i need charged in. Sorry for trouble you.

[Sridhar1312]

find out what is the design suction &discharge temperature and chage and after operating for some time measure the sub cooling and Super heat so that is correct.
all the above is done preferably closer to design conditions.

[A/C MAX]

Dear friends, i am a freshman in this area. Thanks for all guys helping me before in this forum.

Now, i have a question. i bought a L'UNITE HERMETIQUE (FH4518Y) refrigeration unit. There is a oil separator after compressor and accumulator before compressor. The medium is R134a. i want keep the evaporator temperature at about 20 to 25 degree C.

How can i determine the amount of R134a charged in this system? Any corrolation is useful?

Thanks a lot.

Frank,

This compressor work as an Air Conditioning?, 20 to 25 degrees C are the room temperature or the evaporator temperature?

[frank721]

Frank,

This compressor work as an Air Conditioning?, 20 to 25 degrees C are the room temperature or the evaporator temperature?

25 degree C is the room temperature and the target temperature of my evaporator.

According to its catalog, it can work between -30 to 15 degree c of evaporation temperature.

[lowcool]

manufacturers usually rate capacities on coils,add a bit for receiever and liquid line for a rough guide and complete charge with a sight glass,next time you discharge unit use a recovery machine with a bottle and a set of scales.the hierachy also reckons it helps save the planet

[nike123]

25 degree C is the room temperature and the target temperature of my evaporator.

According to its catalog, it can work between -30 to 15 degree c of evaporation temperature.

If the room temperature is 25°C than target evaporation temperature of your evaporator is between 5 and 10°C (depending on evaporator air flow and evaporator superheat).
You cannot have evaporator and room air temperature (evaporator air entering) same, since there will be no heat transfer in that case.

Depending on expansion device type (capillary tube or TEV) you should charge to about 7K subcooling (TEV) or by superheat table (capillary) when room temperature is near designed and condensation temperature around 40°C.

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