AC Technician Didn't Purged Air in pipe ?

[electrosam]

Hello.
I brought Samsung AS10UTA 0.8T AC for my room. The technician came for installation did every fitting properly. In manual it is mentioned that we should purge out air in refrigerant pipes with vaccum pump. And if pipe is greater than 5 m we must fill more R22. It is 5 m only. But he didn't purged out the air. He told it is not necessary and it is difficult too. AC is working fine. But I wanna know is this will affect a lot ?

[Tony]

1. Discharge pressure will be higher than normal.

2. Therefore, will be making compressor work harder, so it will use more electricity.

3. There will be moisture left in the system, (moisture content is in the air), this will create acid, which will gradually eat away at the inside of your system, wherever the refrigerant goes. (This problem depends on how humid it was when the system was installed.)

Ultimately the system was not installed correctly.

Out of interest, did the installer carry out a leak test on the pipes which he installed with OFN, before letting the refrigerant into them?

[taz24]

Hello.
I brought Samsung AS10UTA 0.8T AC for my room. The technician came for installation did every fitting properly. In manual it is mentioned that we should purge out air in refrigerant pipes with vaccum pump. And if pipe is greater than 5 m we must fill more R22. It is 5 m only. But he didn't purged out the air. He told it is not necessary and it is difficult too. AC is working fine. But I wanna know is this will affect a lot ?


The technician did a bad job for you.

The air needs to be removed because it is not refrigerant so it causes problems with the way the system works.
The other reason why air needs removing is because it contains mosture and moistur to a system is damageing.

Thats the bad news, the good news is you may get away with it, if your technician purged the air out by venting the refrigerant through the pipes before he contected the last pipe fitting up.

If you want to be 100% sure you would need to remove all the refrigerant, do a complete vac on the system and charge with new. That will cost though but it is the only way you will be sure it is fine.

Moisture in a system can cause acid and acid can burn the system out, if not treated.

taz

.

[rude]

Difficult to attach a vaccum pump to a unit? Geez i think that would be the easiest thing to do, installing the aircon would have been the harder part.

[Sandro Baptista]

1. Discharge pressure will be higher than normal.

2. Therefore, will be making compressor work harder, so it will use more electricity.

3. There will be moisture left in the system, (moisture content is in the air), this will create acid, which will gradually eat away at the inside of your system, wherever the refrigerant goes. (This problem depends on how humid it was when the system was installed.)

Ultimately the system was not installed correctly.

Out of interest, did the installer carry out a leak test on the pipes which he installed with OFN, before letting the refrigerant into them?



Also the A.C. unit will give less capacity due to higher condensation temperature/pressure and less capacity of the evaporator part. There is a partial pressure of refrigerant, which is not 100%, the other partial pressure is coming from the air/moisture.
So in reality the aircooler will be:

1) Evaporating at a lower pressure (less capacity for the compressor) with high superheat at the outlet;

2) Lower heat transfer coefficient on the boiling side of the refrigerant » less evaporator capacity;

3) Lack of refrigerant feeding the evaporator due the presence of air/moisture which occupies volume and don't let that passes trough the sufficient flow of refrigerant;

4) Because of 1) you may have high frost formation in the firsts parts of the evaporator, where isn't superheat yet. That ice can block partially the passage of air and magnify the problems of lack of capacity.

How long you have the A.C. unit working?
Are you already have the A.C. working in the summer? Does it have the cooling effect/refrigerant capacity that it would be expected in the room?


Try to do the follow test: touch in the condenser coil at rows of the middle and more or less "feel" the temperature. If the liquid line, that feed the evaporator is at a much lower temperature is because there is a important quantity of moisture, which is very bad as have been told to you.


Regards

[electrosam]

Also the A.C. unit will give less capacity due to higher condensation temperature/pressure and less capacity of the evaporator part. There is a partial pressure of refrigerant, which is not 100%, the other partial pressure is coming from the air/moisture.
So in reality the aircooler will be:

1) Evaporating at a lower pressure (less capacity for the compressor) with high superheat at the outlet;

2) Lower heat transfer coefficient on the boiling side of the refrigerant » less evaporator capacity;

3) Lack of refrigerant feeding the evaporator due the presence of air/moisture which occupies volume and don't let that passes trough the sufficient flow of refrigerant;

4) Because of 1) you may have high frost formation in the firsts parts of the evaporator, where isn't superheat yet. That ice can block partially the passage of air and magnify the problems of lack of capacity.

How long you have the A.C. unit working?
Are you already have the A.C. working in the summer? Does it have the cooling effect/refrigerant capacity that it would be expected in the room?


Try to do the follow test: touch in the condenser coil at rows of the middle and more or less "feel" the temperature. If the liquid line, that feed the evaporator is at a much lower temperature is because there is a important quantity of moisture, which is very bad as have been told to you.


Regards

thanks for info Sandro Baptista. I have purchased this AC just a week ago. It is installed on 23 April 2009. Its summer here and it is working fine. The pipe with smaller diameter (liquid line)is too cold and that with bigger diameter(gas line) is less cold. It is properly cooling the room. I didn't installed AC from authorised Samsung technician. The technician was provided by the shopkeeper. He told there is no need to purge air out or fill extra R22 if pipe is <5m.

[casstrig]

Please note that if the installer used the pipe supplied by the manufacturer and in your post it seems that he did,these can be precharged and steeled and not require air purging as there is none to purge.

[chemi-cool]

these can be precharged and steeled and not require air purging as there is none to purge.



You must vacuum the pipes and the indoor unit!

Even if the pipes come precharged [which I doubt..], The indoor unit is usually under dry CO2 or Nitrogen or dry compressed air pressure.

[Sandro Baptista]

thanks for info Sandro Baptista. I have purchased this AC just a week ago. It is installed on 23 April 2009. Its summer here and it is working fine. The pipe with smaller diameter (liquid line)is too cold and that with bigger diameter(gas line) is less cold. It is properly cooling the room. I didn't installed AC from authorised Samsung technician. The technician was provided by the shopkeeper. He told there is no need to purge air out or fill extra R22 if pipe is <5m.

If the liquid line it's too cold (if you measure before the expansion device - capillary or expansion valve) and the suction line is less cold...so it could mean that there is moisture by the facts I told you in a previous post. Even so the fact liquid temperature of the HP line be more cold that the suction line it's a little strange. Have you certain that you measure the HP liquid line (befor the expansion device).
Another thing: the AC can be working fine, but if it has moisture it could working better with more capacity and with less consumption.

Regards

[nike123]

If the liquid line it's too cold (if you measure before the expansion device - capillary or expansion valve) and the suction line is less cold...so it could mean that there is moisture by the facts I told you in a previous post. Even so the fact liquid temperature of the HP line be more cold that the suction line it's a little strange. Have you certain that you measure the HP liquid line (befor the expansion device).
Another thing: the AC can be working fine, but if it has moisture it could working better with more capacity and with less consumption.

Regards

Since this is Split-system AC he talks about, these two lines are actually passive part of heat exchanger and not liquid and suction line. Therefore,in cooling, "suction" line carries superheated vapor, and "liquid" line carries flash gas and liquid refrigerant, and it is perfectly normal that "suction" line is hotter (for superheat amount) then "liquid line".

This kind of "cowboy" installing work is common here in my country with cheap Chinese units (below 170 pounds) and guys are installing them without vacuum drying, pressure testing, refrigerant purging etc.. and nobody complains much, since nobody expect that these units will work well and last more than few years.
But, in fact, it is amazing what these units survive with that instalation practice. And these guys makes big money in comparison with other who do they work as best practice require and according to law and regulations.
Installation is made in less than 2 hours without any trunking or simmilar and it is charged 80-100 pounds (material (20-30 pounds) until 5 m included for 9000-12000 btu units). That is about average week salary here. Of course nobody pays tax., that is work at "black".
When there is summer "AC rush hour", two guys could make 4-5 these instals a day.