Team-BHP - The home / office air-conditioner thread

Hi NevGin,

A few observations:
- Your annual usage hour and assumption of peak power consumption for 100% of the time are liberal and impractical, IMHO. I dont think even a south facing top floor room in Delhi will consume that much.

- Why have you gone into such circuitous calculation to arrive at annual energy consumption? To my understanding, you just have to multiply power consumption (in kW) with usage hour to arrive at total power consumed. For example, for the Daikin R50, 1600w/1000 x 3240hr = 5184 kW hr. Correct me if I am wrong.

- Something is wrong with the Samsung because looking at the btu/hr rating it looks like a 1 ton AC among 1.5 tonners.

Quote:

Originally Posted by khoj (Post 1837783)

In Bombay, 1.2T for the 150sqft and a 0.9 or a 1 Ton for the 110 sq ft room would be sufficient.

See attachment on the multi room split air con.

Thanks will check it out. But I still have one doubt. In case of multi room split acs with one outdoor unit, will both the acs run on full capacity if switched on simultaneously or will the single outdoor unit reduce the colling capacity of both the acs. Is it wiser tio install two separate acs with outdoor units instead of this?

Quote:

Originally Posted by surd_biker (Post 1841204)

.... Is it wiser tio install two separate acs with outdoor units instead of this?

It is definitely better to install two separate units instead of a multi-split.
It is foreseeable that the outdoor unit will give a problem some day. Both your rooms will be without AC!

If space is not a complete crunch, go for two spilt ACs.

Quote:

Originally Posted by Thad E Ginathom (Post 1842267)

The multi-split Hitachi I looked at a few years back was more expensive than two seperate Samsung units!

Even if you compare the same manufacturer's products you'll probably find the multi split to be more expensive than two single splits! Such is Indian pricing!

@surd_biker

The compressor is designed to match the indoor units at full capacity, so the two 1 ton indoors will be mated to a 2 ton compressor. When one indoor is switched on the compressor will run at half capacity or at slow speed which will suffice the needs of the single indoor unit. As and when you switch on the second unit the compressor will increase its rpm and supply the second indoor with the required optimum amount of compressed gas. There is no de-rating as such.

The higher cost of such units is not as simple as premium pricing. A single compressor running two indoor units will have additional equipment to allow the system to work, such as three or four way diverter valves, a variable speed compressor which more often than not will be a DC compressor and the outdoor fan too might be equipped with a dual speed DC motor. All these plus other associated components add up.

Quote:

Originally Posted by anupmathur (Post 1842519)

Even if you compare the same manufacturer's products you'll probably find the multi split to be more expensive than two single splits! Such is Indian pricing!

Like you posted earlier, the multisplit is meant for applications where there is no space for 2 separate condensing units. What you save is space, and not money.

Quote:

Originally Posted by khoj (Post 1842689)

..... will be a DC compressor and the outdoor fan too might be equipped with a dual speed DC motor. ....

Khoj, are there any compressors or fan motors running on DC?
None, I would imagine.

Quote:

Originally Posted by anupmathur (Post 1843031)

Khoj, are there any compressors or fan motors running on DC?
None, I would imagine.

Don't imagine, go back in the thread and read up you will find what all has been running on DC.

Quote:

Originally Posted by khoj (Post 1843040)

Don't imagine, go back in the thread and read up you will find what all has been running on DC.

:eek: Khoj, it's not an easy task to go through 60 plus pages!

Are there any ACs today that have compressor motor and/or fan motor running on DC?

Well nothing in life is easy but there is google.

However any aircon or for that matter refrigerator and now a days washing machines that are advertised as being equipped with inverter technology run on DC. The compressors are variable speed DC compressors and the motors are reluctance free DC motors. Yet all of these run on local AC supply.

Thanks, Khoj, though I don't quite subscribe to calling them DC motors.
The fact that an inverter (as opposed to a rectifier and filter) is being used makes these motors more AC than DC, since the frequency is also being controlled. There is no frequency for DC, hence the very term becomes redundant.

Yes, it has become difficult now-a-days to give exact classificaton to a motor because of the seamless merger of the best properties of each type of motor, AC and DC, that current (motor) control systems allow!

Thanks again, for your inputs. :)

I finally bought a Hitachi Ace Follow me 1.2 Ton ac this weekend. It is 5 star rated and cost me Rs 33000 including installation and 4KVA stabilizer but had to pay Rs 1000/- for the mounting bracket.

I also considered the following:

1 Ton Godrej 5 Star 24900/- incl of install and stabilizer
1 ton Voltas Vertis Gold 25500/- incl of install and stabilizer

For the guys in Bangalore it looks like Unilet is giving the best prices for these ACs and also has stocks, the other places like Girias, Ezone etc did not have stocks or could not match the price. I want to give a thumbs up to Unilet.:thumbs up