[sagpatel]

My 6 year old Videocon 1.5T split AC compressor in my factory has gone bad. I have had several problems with this AC since a year or so (mainly related to compressor and once PCB). I have decided to get a new AC this time rather than repairing as I am simply fed up. I want a 1.5T robust tank like AC which will run fine for at least 6-7 years with regular maintenance. My factory is in Chemical Zone hence any brand which gives chemical resistant coating on compressor parts is a boon. Any recommendations? I have heard Mitsubishi Electric has some good industrial ACs. Please let me know your suggestions.

[PGA]

Originally Posted by ajayc123

Very interesting post. While I would be really interested in knowing the real answer, since a refrigerator with a huge 2 ton compressor could achieve similar results, but I have a bunch of questions for you, instead.

Did you observe if they changed the refrigerant?
Did they tweak / change the thermostat?
Did you notice if the fan/compressor speed different from before?
Did they change any valves in the refrigerant circuit?

To me, these are the possible variables to play with.

Originally Posted by anupmathur

All that is needed is for the thremostat to be tweaked to allow a different operating range compared to the normal 'room' airconditioner mode,.

Originally Posted by Aroy

AC can go really low

Originally Posted by Rshrey22

Does the room have insulated walls? I guess it might be as it is a cold storage room.

Originally Posted by Prowler

Usually there will be a difference of about 7-9 degree C between the grill temperature and the room temperature. There are other factors: size of the room, insulation, thermal load etc.
So if your room temperature is 5 degree C, the grill temperature will be about -3 Degree C which is difficult to achieve in a normal room AC as it will form ice unless the air throw is high.

In your case, they would have added room insulation, increased the internal fan speed to the maximum, bypassed the normal thermostat and in its place, placed a lower range electronic thermostat. l.

Thanks a ton for all these pointers. I am attaching some photographs of the setup below.

Answer to some of your queries:-

Yes its a room made out of PUF panels, got about 2 inches thick insulation.
No mods or refrigerant change has been carried out on stock ac.
Thermostat has been changed and an additional sensor placed too, in the black tape below ac. Also its no longer connected to orignal pcb but to the additional one as shown in photographs.
The ac runs on max fan speed when its in operation. Refrigerant of the ac is not mentioned in the docs anywhere.
The temperature does not go down linearly but in steps and compressor keeps on cutting off very regularly even when the temperature has not reached 5 deg.
Company has advised me not to run the unit with RH below 60%, they said it will not attain the temperature below that humidity levels. A humidifier has been attached along with the system.

So what I gather now is that its electronic thermostat connected that does the trick and its possible to lower the cooling of a commercial grade ac as the output air is in the region of -3 degC.

[Prowler]

Originally Posted by PGA

So what I gather now is that its electronic thermostat connected that does the trick and its possible to lower the cooling of a commercial grade ac as the output air is in the region of -3 degC.

Like I said earlier the difference between the room temperature and the grill temperature is 8 degrees resulting in the output (grill)temperature sitting at -3 degree C.

They have shorted out the thermostat and instead they use the black box containing the electronic thermostat. In addition I can see a cable running inside the AC, probably attached to the compressor so that it can detect over heat conditions and stop the compressor. The integral mechanical OLP (over load protector) will not help in this case.

I suggest that you add a SONOFF WIFI switch which will give you the actual consumption on a day to day basis. The company's thermostat/control circuitry will tell them how much it consumes - but I don't think they share the information with you.

[Aroy]

Interesting use of an air conditioner. Normally for refrigerators and freezers a different refrigerant is used that can easily go down to -40 degrees, but it seems that even an AC refrigerant is good enough for 0 degrees.

[sagarpadaki]

How are Blue star AC's. Looking at their NON Inverter( Fixed speed) AC in 1.5 ton capacity. The blue star brand is not discussed much on this thread. Any long term users of the AC, can you please provide your feedback on the quality of their AC's?

Any strong recommendations for Non Inverter AC's? There are barely a few brands still offering them - BlueStar, Daikin, Carrier, Midea

[Aroy]

Originally Posted by sagarpadaki

How are Blue star AC's. Looking at their NON Inverter( Fixed speed) AC in 1.5 ton capacity. The blue star brand is not discussed much on this thread. Any long term users of the AC, can you please provide your feedback on the quality of their AC's?

Any strong recommendations for Non Inverter AC's? There are barely a few brands still offering them - BlueStar, Daikin, Carrier, Midea

Blue Star is a major player in Industrial HVAC. Their fixed speed AC's were excellent till a few decades ago, till Japanese and Korean players come. Now a days I believe that their domestic AC's are not manufactured in house, most probably OEM from China.

Both Inverter as well as Non Inverter AC have a mother board for controlling the various functions of the AC, unlike good old days when there was no electronics, three or four speed fan selected with a rotary switch, a fixed speed compressor with an electro-mechanical thermostat, no swinging louvers and of course no failure of electronics.

For consumer ease all the functions are now controlled by mother board (my Hitachi had an MB 15 years ago), hence there is not much difference in failure rate between Inverter and Non Inverter AC.

[anupmathur]

Originally Posted by Aroy

Interesting use of an air conditioner. Normally for refrigerators and freezers a different refrigerant is used ...

It is not quite correct to believe that different refrigerants have to be used for refrigerators and freezers. R12, R22 and any of the newer ones can do the job. Being a shippie I can tell you that on board ship we used to maintain our (cold rooms for food) meat room at -18°C and the fish room at -28°C with R12 (and on later ships with R22).

[Arun_S]

Originally Posted by sagarpadaki

How are Blue star AC's. Looking at their NON Inverter( Fixed speed) AC in 1.5 ton capacity. The blue star brand is not discussed much on this thread. Any long term users of the AC, can you please provide your feedback on the quality of their AC's?

Any strong recommendations for Non Inverter AC's? There are barely a few brands still offering them - BlueStar, Daikin, Carrier, Midea

I have Blue Star, Daikin and Carrier Non Inverter ones. Both B & C are 7 year old, while Daikin is 8 months.
We had lot of issues with Blue Star, as mentioned our lot was manufactured in China. Indoor unit changed within 2 months of purchase, 3 times gas refill etc. But I hear now they are manufacturing in India.

Carrier comparatively is good, no major issues, had to replace gas only once. Service is good.

Daikin having an issue, service i have been chasing for 3 weeks.

[sandeepmohan]

Originally Posted by sagarpadaki

How are Blue star AC's.

They are still pretty good. As already mentioned, a lot of their units, especially the indoor units are sourced out of some OEM from China. That OEM isn't the best. They used to do a better job when they were manufacturing in India. I don't know why they gave it up to China. Their outdoor units are solid. I've got a mix of Made in India Outdoor and a Made in China indoor unit from Blue Star. No complaints but I can tell quality isn't what it used to be. The only saving grace being Support. A Technician isn't too far away if I need one and I've used it only to relocate the unit once. They did a tidy job.

I used to recommend Blue Star a lot. With brands like Panasonic, Daikin, Mitsubishi and LG all selling for a similar price, its getting hard to make a strong case for Blue Star anymore. The quality is better with Japanese, Korean units.

Heck; if I must buy something now, I'd probably risk it and buy a Midea. They own Carrier and are OEM to several manufacturers. Support might be the only issue as they are not that widespread.

[sagarpadaki]

Originally Posted by sandeepmohan

Heck; if I must buy something now, I'd probably risk it and buy a Midea. They own Carrier and are OEM to several manufacturers. Support might be the only issue as they are not that widespread.

Thanks. I will drop bluestar from my list.

Will check the carrier/midea and daikin for the non inverter AC's.

Reliability is the most important thing for me with AC. We have an LG AC that is 14 years old and runs like a dream. No breakdown. If LG were offering fixed speed AC, I would have purchased those only.

[Aroy]

As far as I know there are only a few domestic AC's manufactured in India, most of them are imported. I know for sure that LG and Hitachi manufacture at their factories. No idea of Daikin, Panasonic or Mitsubishi.

Carrier, Blue Star and Voltas are old players in both Industrial as well as domestic HVAC. So if they do manufacture in India and have good service network, they are worth looking into.

My priorities while purchasing AC is
. Star rating
. After sales service
. Extended all in one warranty

which ever brand ticks these at a reasonable cost, gets my money.

[Gansan]

^^ I read that Panasonic has a factory in Pondicherry. And that even the General brand is contract manufactured by them.

[Aroy]

Originally Posted by Gansan

^^ I read that Panasonic has a factory in Pondicherry. And that even the General brand is contract manufactured by them.

Most of the players are in industrial compressors - 10T or more. Domestic compressors are of capacity of 1T, 1.5T, 2T or 3T and are manufactured in large (> 50,000 per annum) quantities. Refrigerator compressors are even more.

Most of the Domestic AC's are assembled in India. Plastic parts and even heat exchangers are made in India. In most of the cases the electronics is imported and in very few cases the PCB/MB are assembled, most are just imported. Whether the compressors are manufactured in India is the question.

[Maverick Avi]

Originally Posted by sagarpadaki

Thanks. I will drop bluestar from my list.

Will check the carrier/midea and daikin for the non inverter AC's.

Reliability is the most important thing for me with AC. We have an LG AC that is 14 years old and runs like a dream. No breakdown. If LG were offering fixed speed AC, I would have purchased those only.

A 14 year old A/c was definitely build to last, be it LG or Voltas. But not anymore. In my search for a reliable A/c I have tried brands such as Voltas, Carrier, Bluestar and Daikin. Have had gas leaks in all by 5th year except for Daikin(3 months old) and Bluestar(5 years old). Carrier experience has been worst with gas leak in 4th year(twice) and blower motor failure in 5th with another gas leak. Voltas experience has been average but they were easily repaired from outside. Bluestar has been trouble free and has good cooling experience. Daikin is good but quality is nowhere what I was expecting from this Japanese giant.

If you giving reliability the top most priority I would suggest giving a look at Panasonic. They have anti corrosion coating on condenser as well as cooling coil so should be better equipped to handle gas leaks. Their PCBs are also robust and sometimes they provide good extended warranty options.

[sagarpadaki]

Originally Posted by Maverick Avi

If you giving reliability the top most priority I would suggest giving a look at Panasonic. They have anti corrosion coating on condenser as well as cooling coil so should be better equipped to handle gas leaks. Their PCBs are also robust and sometimes they provide good extended warranty options.

Thanks for your recommendation. But Panasonic does not offer non inverter AC.

The room in question is an odd shape and the roof gets direct hit from sunlight for 6 hour during summer. Also, we will be using the AC only for 4 months an year - Feb end to June mid. These two factors rule out the inverter AC. Also, the inverter AC's are very expensive to repair if something goes wrong with the PCB after the warranty period.

Hence the need for 'reliable' fixed speed AC.

Edit - I checked Panasonic India website and they do offer fixed speed AC's. Let me pay them a visit. Thanks