Inverter Type AC in Pakistan (Inverter/Non Inverter Dedicated Discussion)

[Xulfiqar]

any AC install job without a vacuuming down is not an install job.

Its robbery/jugaarbaazi/morons with tools problem.

[tahamujtaba]

99.9 % a.c technitions are fimmilar with vaccum method. Either we need to purchase vacuum pump ourself or pay a bit extra to person who does job properly if one finds one

[Xulfiqar]

If the tech is aware of the necessity then why does he not own this tool? - By that rationale if you take your car to a mechanic you also need to provide tools for him?

[nfssaad]

this was actually the case, when i needed a timing belt job, took my own torque wrench with me..

[HellsGuardian]

Sir you are well aware of conditions here. We go for shortcuts whenever we can and then there is this ustad g culture. Making them understand is like banging your head to the wall. In such case, we are forced to pay extra to someone who does have vacuum pump but in the end it is still worth it

[Panther]

Thry just want to save on time and effort specially during the working season.
I specially asked the installer to bring the vacuum pump along other wise I will send you back. He did bring the pump and did the job well but said he will charge Rs500 extra for pump next time.

[IceCold]

Does the inverter need any special kind of setting or adjustment to work for heating? I ask this because when i installed my Orient there is a small plastic device that the installer did not fit while installing however he said this is needed if you want to use it for heating.

[nfssaad]

show the picture of it

[HellsGuardian]

Are you talking about drain plug extension on outdoor unit? It just plugs in to a drain hole so that you can attach a pipe to it but that's not mandatory. I am using it for heating and don't think any setting is required. You can always consult the user manual. Oh and user manual has a line in bold that says to vacuum it.

The heating mode is quite nice what am going to explain now is all done automatically by AC. At start it runs the compressor however indoor blower remains off (extremely slow), after a while when indoor unit starts to get heated up then it runs the blow at low speed with air direction vanes towards roof (highest setting) and after sometime, it sets the blower speed to high and turns the vane towards ground(lowest setting).
This is really good as it doesn't start throwing cold air on you, it only starts throwing air once it is heated enough and the turning of vanes towards ground is good too as we know hot air rises up and cold air sinks down so they did this to
1. create a convection current within the room
2. keep the ground level warmer so it is comfortable for people
3. if they don't point to ground then all hot air will accumulate at roof and cold air will sink at ground level so not really efficient, plus the thermo-couple on inlet will read a higher temperature whereas you will still be feeling cold comparatively.

These inverter ACs heat up the room very quickly because of large airflow as compared to any other method and are certainly easy on pocket as compared to other methods. The hybrid heaters are even more easy on pocket if your house has no natural gas issue in winters. But a good hybrid heater is easily 8-12k in price so why pay more when you can get the job done by paying a few hundreds in one winter using your AC.

[IceCold]

Are you talking about drain plug extension on outdoor unit?

I believe so, will try today. Its actually installed in my mothers room and its getting really really cold in Lahore these days so will try out today.
Thanks for the detailed explanation.

[HellsGuardian]

I suppose on heating mode, the AC throws water from outdoor unit (as opposed to indoor in-case of cooling) so that is just a plug to help you connect a pipe to outdoor drain hole. You can share a picture of that thing. I normally use my AC at 19-20 setting in morning and after an hour or two, i turn it off and room remains comfortable enough for whole day.

[IceCold]

I suppose on heating mode, the AC throws water from outdoor unit (as opposed to indoor in-case of cooling)

Exactly. This is what the installation guy said that the operations are reversed in heating mode. So if you dont connect it that means water will just splash out from the outdoor but otherwise no harm done.

[HellsGuardian]

You can plug it yourself. He must be putting it into the wrong hole.
No issue if you don't plug it apart from water droplets on surface below where outdoor is installed. Just use it on heating

[mafiadog]

So they samsung technician came and was not carrying vacuum pump with him so i denied him work and told him to come back with a vacuum pump the next day. He was carrying with him normal gauges only and kept insisting that he's using the purging air method and there are different ways to achieve the same result. He told me that since Samsung units are assembled in Pakistan they are pre vacuumed before being sent for installations. I however did not agree to his method and told him to come today. He sent me this today copied from sunfrost website :

We have developed a method of removing the air from a system without the use of a vacuum pump. The method requires the installation of an access valve on the high and low side of the system.
Evacuation Procedure

1 - With the new compressor installed, turn on the compressor and depress the access valve on the high side of the system. Monitor the pressure on the low side of the system. When the pressure is as low as it will go, close the access valve on the high side of the system and turn off the compressor. This process will take about 5 minutes.

2 – Charge the low side of the system to approximately 14 psi.

3 – Wait about 3 minutes for the pressures on the high and low side to equalize.

4 – Now turn the compressor on and depress the access valve on the high side. When the pressure on the low side is as low as it will go, let the high side access valve close and turn off the compressor.

5 – Repeat steps 2, 3 and 4. Note, on successive evacuations, the low side pressure will not go as low because of the absorption of refrigerant in the compressor oil and it’s slow release.

6 – Charge the low side of the system to approximately 14 psi.

7 – Wait 3 minutes for the pressure to equalize. Turn on the compressor and depress the access valve on the high side. This time, when gas is no longer coming out the high side access valve, let the valve close. The air is now purged from the system.

8 – Charge the system with the appropriate amount of refrigerant and turn on the compressor.

9 – Make appropriate adjustments in system charge if necessary.em change if necessary.

[mafiadog]

After much pressure , he caved in and said he will bring a vacuum pump for my satisfaction. Can someone guide me what else should i look for and how should i make sure he is correctly using the vacuum ? what about weighing ?

[HellsGuardian]

All units are pre-vacuumed but when your connect the pipes and open valves, there is air in moisture which enters the system. Ask him these questions:
How do you make sure that all air and moisture left the system by purging?
How do you know that more impurities were not introduced in system by purging?
How do you know how much refrigerant was lost in purging? You might have an under-charge now.

This purging method is old and preferred way is to use the vacuum pump.

[HellsGuardian]

Open the user manual and i am sure you will find a line where it says to vacuum the system with a vacuum pump. The method you shared above works for refrigerators i think, for split AC with prefilled charge, i don't think its applicable. @Xulfiqar can confirm this

[mafiadog]

Thanks guys , I might ditch their official free installation service and pay for labour to someone who can properly install the unit. Please let me know if there is anyone in Karachi who can provide me with the proper installation ?

[ch.talal]

So they samsung technician came and was not carrying vacuum pump with him so i denied him work and told him to come back with a vacuum pump the next day. He was carrying with him normal gauges only and kept insisting that he's using the purging air method and there are different ways to achieve the same result. He told me that since Samsung units are assembled in Pakistan they are pre vacuumed before being sent for installations. I however did not agree to his method and told him to come today. He sent me this today copied from sunfrost website :

We have developed a method of removing the air from a system without the use of a vacuum pump. The method requires the installation of an access valve on the high and low side of the system.
Evacuation Procedure

1 - With the new compressor installed, turn on the compressor and depress the access valve on the high side of the system. Monitor the pressure on the low side of the system. When the pressure is as low as it will go, close the access valve on the high side of the system and turn off the compressor. This process will take about 5 minutes.

2 – Charge the low side of the system to approximately 14 psi.

3 – Wait about 3 minutes for the pressures on the high and low side to equalize.

4 – Now turn the compressor on and depress the access valve on the high side. When the pressure on the low side is as low as it will go, let the high side access valve close and turn off the compressor.

5 – Repeat steps 2, 3 and 4. Note, on successive evacuations, the low side pressure will not go as low because of the absorption of refrigerant in the compressor oil and it’s slow release.

6 – Charge the low side of the system to approximately 14 psi.

7 – Wait 3 minutes for the pressure to equalize. Turn on the compressor and depress the access valve on the high side. This time, when gas is no longer coming out the high side access valve, let the valve close. The air is now purged from the system.

8 – Charge the system with the appropriate amount of refrigerant and turn on the compressor.

9 – Make appropriate adjustments in system charge if necessary.em change if necessary.

You need to vacuum the pipes coming from outdoor unit to indoor unit and that is must for these locally assembled air conditioners,

I got contact of AC installer who uses vacuum pump but he lives in Lahore.

May be buy your own vacuum pump because if you need to service air conditioners and refill refrigerant, you will again need that.

Mini portable vacuum pump will cost you around 5000 - 10,000 rupees depending on its quality.

[Xulfiqar]

vacuuming the lineset is mandatory regardless of country of manufacture. The core concept behind vacuuming is that absolutely nothing other than refrigerant should be in the lineset once the block valves are opened.

no purging, dua, mannat, jadoo can replace the vacuum pump vacuuming the lineset.

If you have opened the block valves in an "atmosphere" lineset - your refrigerant is now trash as its adulterated with air. Its heat exchanging capabilities are cut by more than 50%.

if the idiot installer gives you a cock and bull story of "tajurba" or shows you a page for "purging" or some other BS - kick him out and hire a different tech.