[infotech58]

Thanks for the response guys.

The room does get direct sunlight through the roof. Probably I'd move this unit to another room in the house and install a 1.5 ton here.

Originally Posted by roy_libran

If this is a room that receives direct sun light, then 1 ton will fall short for circa 120 sq. Ft.

Originally Posted by R2D2

More an issue with the AC's sizing - you should have purchased a 1.5T for that room. Now that you have a 1T don't expect it to cool down to 16C in temps of 40+ degrees. That would be difficult for a 1.5T too.

Originally Posted by anupmathur

If the room has no direct sunshine on the roof/slab a one ton ought to do the job most of the time. On days when the mercury crosses 42 or 44°C the unit will struggle.

Originally Posted by bluevolt

Make sure that outdoor unit is having proper ventilation and install a shade over it if it is getting direct sunlight in afternoon.

[aks_karthik]

As i planned to install 2 or 3 AC's for my new house, i have searched for some good discount around Chennai for Panasonic AC's.
Finally i got a quatation from one of my friend with Dealer Price.

Panasonic Chrome Inverter 1.0 Ton AC + V-Guard VWR 400 Double Boost Stablizer + Free Installation + Delivery for Rs. 40000 (44250 in other shops)

Panasonic Jade Inverter 1.0 Ton AC + V-Guard VWR 400 Double Boost Stablizer + Free Installation + Delivery for Rs. 37000 (41000 in other shops)

Seems this is the best price I could able to squeeze the price.

Guys, If anyone knows more discounts, Please let me know the store and price. I need to decide it before this month.

[Aroy]

Originally Posted by infotech58

Thanks for the response guys.

The room does get direct sunlight through the roof. Probably I'd move this unit to another room in the house and install a 1.5 ton here.

The cooling depends on these factors
. Size of the room ~ 1000 cubic foot/ton
. External heat load through direct sun on windows, walls and roof
. Number of persons in a room ~ 4 persons/ton
. Number of times the doors are opened
. Ambient temperature

To check if the sizing is wrong do the following
1. Measure the outlet temperature after two hours of running. If it is 17 degrees or less then you have undersized AC.

2. If you have access to the ODU, trickle water slowly on the condenser for at least half an hour. If the room temperature comes down, then the AC is fine but the heat load in the room too much for the 1 ton AC. When Votas was reining in the AC market (25 years ago), the window AC used to come with a water tank. In peak summer you were advised to fill that tank and let the water trickle down on to the condenser - increasing heat transfer for the under sized unit.

Now for sizing
The AC is reducing the temperature from 36 to 28 that is 8 degrees. To get it down to 20 you need another 8 degrees, so even a 1.5 ton will not do.

If you really wan it down below 20 degrees in peak summer, get a 1.5 to 2.0 ton Inverter AC. These have a nominal rating of at least 15% more at peak load so a 1.5 ton will cool like a 1.8 ton AC and then throttle down to as low as .3 ton to give you a sustained uniform temperature in the room.

[Guite]

My travails with Daikin service has not ended yet. After the ice formation incident, it was serviced by our regular mechanic. He is also Daikin certified but was approached directly by us. After that, fearing compressor problem and since the product is still within warranty we lodged a formal complaint with Daikin customer care.

The personnel sent by Daikin came, assessed and gave estimate. After his estimate was approved by us he came the next day and filled up nitrogen (?). He told us not to operate the unit for one day, saying he will come back next day and check whether there is any leakage. He came next day and said the system needs to be flushed, so he connected what he call a vacuum machine. He filled up refrigerant gas and left after testing it.

The AC unit was operational for sometime. Next day the compressor shut off on its own (no cooling). It came back on after few hours. During this intervening time we also switched off the socket. This on off cycle went on intermittently for the last three days. We have lodged formal complain again and this time the mechanic says he will fill N2 and observe for two days.

There is a peculiar side to this hot cold cycle. The condensed water pipe of the apartment above was dripping water on our bundle of refrig pipes, power cable and drain pipe. After we removed this pipe from above we have had an undisturbed sleep last night. Is there a technical explanation or is it coincidence?

Edit and PS: the mechanic sent by Daikin insists that there is no problem with compressor, saying if it is compressor problem the system will not run at all. His stand is that an AC compressor is either good = ON, or it is bad = does not ON; nothing in between.

[Aroy]

Originally Posted by Guite

My travails with Daikin service has not ended yet.

Edit and PS: the mechanic sent by Daikin insists that there is no problem with compressor, saying if it is compressor problem the system will not run at all. His stand is that an AC compressor is either good = ON, or it is bad = does not ON; nothing in between.

There is a third state - compressor worn out. Here the compressor works but he cooling is low. This usually happens after a few years of running, but at times due to manufacturing defects it can happen in a new unit.

[bharatbs]

I am using a Sharp XP13LV, 1 tonne inverter AC in a 15X11.5 size room and I am very satisfied with this AC unit.

In Bangalore you will typically need the AC for two-three months. Right now in June it is already cool enough that you don't even need a ceiling fan (un-less your room is on the top floor of your building).

Cost: Paid Rs 32,500 at Devi's Jayanagar, Bangalore. Installation cost was separate as below.

Room size: For Bangalore, if your room is not directly sun facing. IMO you can use a 1 tonne AC AC for rooms up to 160 square feet.

Installation: I paid Rs 1,000 for installation + 1,900 for the external stand + 400 for extra cable, plug and plastering. The installation was not done professionally; they did not have any instrument to check the refrigerant gas pressure. They were using a hammer drill and a 2 feet long drill-bit to drill through my apartment wall and it just broke after he hit the re-bar in the concrete, after that they started chipping away with hammer and chisel and my bedroom looked like a war zone. However in the end they got the job done.

Usage: I installed the AC in my bedroom and I temporarily shifted my home office to the bedroom, so I typically used the AC for 12-18 hours for at least 5 days a week. I typically set the temp for a pleasant 27C as I had to switch between rooms which did not have AC. I used an Acu-Rite temperature and humidity monitor to verify the temperature and it always indicated 1 degree below what the AC unit indicated, so the AC is very accurate.

Inverter: The inverter functionality is evident and really effective. Once it cools the room, the AC operates very gently indicating that it is consuming very little power. The XP13LV model does not have real-time tonnage indicator.

Ionizer: It helps bring down the dust and other pollen in the room, it is difficult to measure its effectiveness.
I tried experimenting by smoking in the room with the Ionizer turned on and it did not really take away the cigarette smell, like some people had pointed out on other forums. Unlike window Acs, Split Acs do not bring in fresh air from outside, they just re-circulate the air in the room.

Power consumption: I got a single current bill for April and May which was Rs 1,580. My regular current bills are between 600-800 per month so I was really surprised to see that there was no impact of using the AC. However I was out of station for 10 days during that period. So don't know what to really make of it.

Hardware: The internal and external unit are manufactured in Thailand, at least the one I got was manufactured there.
The AC comes with a sharp ac installation kit which includes all the necessary piping for the installation.
The external unit is quite large, weighs in around 25-30 kgs. But it operates gently and you can hardly hear it.

Manual: They have a small 5 page manual, which is obviously written by a non-native english speaker so it is not very descriptive.

[skumare]

Originally Posted by bharatbs

...Unlike window Acs, Split Acs do not bring in fresh air from outside, they just re-circulate the air in the room...

Hmmm... When the ambient temperature is 25 or below and the room temperature is a bit higher than that, I switch on the a/c assuming that the compressor will not be switched on and the outside air is pumped into the room. Need to rework on the logic, if aplit a/c can't pump in fresh air. Isn't this limitation on split a/c make it inefficient in some conditions?

[bharatbs]

Originally Posted by skumare

Hmmm... When the ambient temperature is 25 or below and the room temperature is a bit higher than that, I switch on the a/c assuming that the compressor will not be switched on and the outside air is pumped into the room. Need to rework on the logic, if aplit a/c can't pump in fresh air. Isn't this limitation on split a/c make it inefficient in some conditions?

That is how split Acs work. More here: http://www.doityourself.com/stry/how...-conditioner#b

While ventilation is good on the downside it may increase the load on the AC as it now has to cool hot air coming from outside.

Window ACs typically come with a ventilation regulator so that may be more desirable in your case.

[Sandeepm777]

Hi,
I am planning to install a Daikin/Mitsubishi vrv/ vrf unit in my new house being built on 3 levels with a carpet area of 5500 sq.feet.
Have spoken to a lot of vendors & am getting a mixed bag reaction with more favouring the traditional split systems.
Any views on the same would be appreciated.

Thanks.

[Aroy]

Originally Posted by Sandeepm777

Hi,
I am planning to install a Daikin/Mitsubishi vrv/ vrf unit in my new house being built on 3 levels with a carpet area of 5500 sq.feet.
Have spoken to a lot of vendors & am getting a mixed bag reaction with more favouring the traditional split systems.
Any views on the same would be appreciated.

Thanks.

The upside of individual splits is that you control what is on and what is not. If in the 5500 sq. feet you need to cool only 1000 most of the time and that too at different levels, then individual splits are more economical.

In case of vrv/vrf you get a one big package. For 5500 square feet I think it will be in the range of 40+ tons. In general you would apportion the IDU as follows

. 4T units in living room and other large areas where a lot of people will be expected - living room, recreational rooms, gym etc
. 3T units large areas where less people are expected at a time - dining areas, home theater, kitchen
. 2T units in large bedrooms
. 1.5T units in smaller rooms
. 0.75-0.5T in toilets and stairwell

The calculation for tonnage depends on the maximum load, so if you expect that 3000 sq. feet with 50 persons are to be cooled to 20 degrees in peak summer you need around 30T, even though the IDU add up to 40-50 tons.

In my experience both the vendor and the user generally err in installing smaller sizes than needed. For integrated system as in your case use the following to arrive at a nominal sizing
. 1T for every 1200 cu.foot ~ 150 sq.feet
. 1T for every 5 persons
. 1T for every 3KW power consumed by appliances (lights, electronics, refrigerators, etc.)

VRF units are highly efficient in the 120% - 20% of rated capacity, so if you install a 35T unit you can go down as low as 7T at high efficiency and to 3T at lower efficiency. In case you use multiple units, then judicious layout will let you go down to 2T. You can consult the following document for further details.
http://www.daikinindia.com/pdf/VRV-Water%20Cooled.pdf

As the systems of this size are extremely expensive, your best bet is to discuss your requirement with Daikin, after studying the above document thoroughly. You will need to install
. ODU of sufficient size. Whether air cooled or water cooled depends on the space you have and the water supply quality at the site. Water cooled have better efficiency in larger units. You may also opt for multiple 10T units working in tandem.
. Location and sizing of the IDU
. The type of management system
. Piping scheme - number of branches

[anupmathur]

Originally Posted by Aroy

....You may also opt for multiple 10T units working in tandem.
....

It is always prudent to have redundancy built into a system. I would hugely favour multiple units.
Water cooled plants consume far less power. Try to get such units from Daikin; they have vast experience in Marine Package Units.

[manim]

Having a new problem with my Daikin Inverter (model: FTKD60FVM) 15 months old.

The indoor-fan makes an intermittent noise and the cooling capacity has become low.
Have contacted service.
Losing faith in Daikin, hope it is a minor problem

However the earlier problem I had does nor re-occur (blinking-led and not starting with U4 error-code).

[R2D2]

Originally Posted by manim

Having a new problem with my Daikin Inverter (model: FTKD60FVM) 15 months old. The indoor-fan makes an intermittent noise and the cooling capacity has become low. Have contacted service.
Losing faith in Daikin, hope it is a minor problem However the earlier problem I had does nor re-occur (blinking-led and not starting with U4 error-code).

A U4 code denotes communication failure between the IDU and ODU. Could be something as simple as the inter unit wiring being faulty and the IDU fan not starting up or running intermittently. You can use your remote control to diagnose the fault.

[manim]

Originally Posted by R2D2

A U4 code denotes communication failure between the IDU and ODU. Could be something as simple as the inter unit wiring being faulty and the IDU fan not starting up or running intermittently. You can use your remote control to diagnose the fault.

I did use the remote to find the fault (got details from the internet).

The 'U4' error also occurs due to faulty electrical-supply (from Daikin technical manual on the internet) which I believe was the case with me. I got this regularly earlier. Now it solved itself (maybe because of better/clean EB supply).

My present problem is that I do not get any error-codes, rather there is a intermittent 'whoosh' noise from the fan and the cooling suffers (I have a Casio-Hygrometer which gives the room Temperature & Relative-Humidity). I have registered a complaint on Daikin web-site and also informed the installer.

Since it is a week-end I may get a service call in a couple of days.
Will post feedback here.

[R2D2]

Originally Posted by manim

The 'U4' error also occurs due to faulty electrical-supply (from Daikin technical manual on the internet) which I believe was the case with me. I got this regularly earlier. Now it solved itself (maybe because of better/clean EB supply)..

AFAIK the unit will shut down automatically if the voltage is outside its normal range.

The range is very wide - 170 to 265V and it does not need a stabiliser though I am using the one the was fitted to my old room AC.

Our 2nd Daikin Split AC dates back to 2004-05 and also works without a stabiliser. But I am thinking of getting a stabiliser for this machine too.

If you have supply quality issues (voltage spikes/sags) in your area it would be better to use one.

Originally Posted by manim

Since it is a week-end I may get a service call in a couple of days. Will post feedback here.

Would be good if you can share your experience with their service.