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

Quote:

Originally Posted by Aroy (Post 4366526)

If a space is cooled locally, then the AC may not cut off, so the compressor will run longer, which translates to higher electricity bill. If you take a nominal figure of 1200W/ton, then for a 4 ton AC you will be incurring 1.2x4 ~ 5 units of electricity per hour - that is the cost of comfort!

You get Floor Standing AC in various capacities. I thing LG starts with a 2 Ton and goes all the way to 20T+. These are Commercial Spec AC, so they a hefty air throw and are much more rugged than home AC.

Thanks for the reply. The space is about 14000 cubic feet. I could separate the kitchen and recreation room with sliding doors which will bring the size down to about 10000 cubes. But the fly in the oinment is the pergola, which is open to the sky. So cooling the entire space is almost out of question.

Which is why I was pondering about local cooling. 5 units per hour would be abbout 60 per day which is about Rs 300 per day. Run for 5 months per year, works out to 45000 a year. Expensive!

Quote:

Originally Posted by civic-sense (Post 4366287)

Is it effective in homes?

The tower units are very effective provided you have the space to place them on the floor. They don't take up much floor footprint but it is a space lost versus having something mounted on the wall. The main advantage is much higher air flow which can cool a larger area.

For a very large area, I would split the load into two 1.5 ton (or 1.5+1 ton) units rather than one unit work over time. You will also have to operate it no lower than 25 degrees. Running it at 22-23 degrees will be pointless as it will work over time as the area to cool is vast. Besides; the main idea is to bring down humidity and temperature to a comfortable level (Not freeze) which can be achieved easily.

Splitting the load also allows you to run just one unit as and when you need it for localized cooling. It is not a scenario where the units are going to be operating 8-9 hours straight like a bedroom aircon.

I also recommend only Inverter units. The ability to control compressor speed based on load is the main advantage.

Quote:

Originally Posted by Aroy (Post 4366526)

An alternative that is twice as expensive initially, but has less than half running cost is to get a high capacity package unit.

The investment on hardware is significant on packaged aircon units for a home and noise levels are much higher. They will most definitely cool down a large area in a matter of minutes. Besides; they come in the way of aesthetics with all the ducting and what not.

Quote:

Originally Posted by sandeepmohan (Post 4366637)

........

The investment on hardware is significant on packaged aircon units for a home and noise levels are much higher. They will most definitely cool down a large area in a matter of minutes. Besides; they come in the way of aesthetics with all the ducting and what not.

Actually large package units are extremely quiet, as the noise making ODU is placed outside and can be 10m away from the room.

One method of reducing cooling effort with pergolas, is to have a movable covering, that will be closed during summers and rainy season and open to sky during pleasant times.

Quote:

Originally Posted by Aroy (Post 4366806)

Actually large package units are extremely quiet, as the noise making ODU is placed outside and can be 10m away from the room.

I was not worried about the ODU. This is anyway outside in any aircon application. Moreover, being a lower tonnage, it won't be loud anyway. My concern was the noise from the AHU. This can be placed externally but requires space. Can be suspended from the roof too but you'd ideally want to conceal it. These things don't look pretty. More than space, the air flow noise is much higher than a Tower unit (Forget Split units). It is high enough to the extent that the draft of air coming out of the ducts will require that you crank up the volume quite a bit on your TV, etc. I am not ruling it out as a solution but noise needs to be considered. I know for a fact that Blue Star AHU's are far from quiet. Some of them have the compressor units in the AHU itself and not the ODU. Maybe others brands are better designed.

Quote:

Originally Posted by sandeepmohan (Post 4367197)

There are two types of package units
. Those that circulate cold air from AHU
. Those that split the refrigerant and pipe it to separate IDU

The former are mainly for large capacity units 100tr onwards, while the later are more compact and in use where the IDU are not always on.

With the latter, I think that you are in for some surprise. IDU of all package units are very quiet, and come in various mounting styles
. Wall mounted like split units.
. Wall corner mount
. Ceiling mount
. Floor mount
and some more styles. The IDU range from 1/2 to 4 tons.

Please visit the LG, Diakin, Blue Star and other commercial air conditioning sites to get an idea of the variety of IDU and ODU's.

Quote:

Originally Posted by anupmathur (Post 4367427)

Example, please! I have never encountered a unit of this kind.

I do not have any visual examples to share but I am pretty sure that if you call up any aircon engineer, they can confirm that such a unit exists.

Back in 2002, when I was working for a Animation studio in Bangalore, we needed a cooling solution for a high capacity compute cluster or render farm as we call it. The AHU Blue Star installed had the compressor unit inside the AHU and not the ODU. In fact, there were two compressors in the AHU. The solution we wanted was something that needed to run 24/7, all year. The design of the unit was such that if one compressor were to fault or fail, the second one took over. Even during standard operation, the compressors would alternate operation. If there was excess load, both would run.

Blue Star DPAG 661R2, 1322R2, 1983R2 have compressors located in the floor mounted indoor unit.

Quote:

Originally Posted by Aroy (Post 4367283)

Those that split the refrigerant and pipe it to separate IDU

Yes; I have seen these units too. I am not convinced it can suit every home. This needs to be evaluated. It is also down to cost. It is a LOT versus a 2 ton tower or split which can be installed in less than a day and causes no problems to the aesthetics of a home.

If you say noise is well controlled, I leave it at that.

Went to the Daikin dealer a few days ago with the intention of buying a 1-ton non-inverter model. We were told that it would certainly be enough for the room size.

On enquiring for a spare-part original-Daikin remote for our second-hand 1.5 ton, we learnt that it is of 2013/14 vintage, and an imported model, and yes, the remote should be available.

Hoping the home-built machine is anything like as good. And that they don't build them like than any more doesn't apply too much!

We held fire on the order: "pollution-proofed" model should be in stock next week. If it is, we will go for that.

One thing we can't decide is... should we swap the older machine, 1.5-ton, to the bigger room, and install the new machine, 1-ton, in the smaller room which we actually sleep in.

Given our staggered sleeping hours, the sleeping-room AC gets as much as twelve hours use every day. That is most really nearly every day of the year. Note: we only cool the room to 25 or 26 degrees.

The other room, as well as housing a lot of clothes and shared stuff, acts as wife's den for a few hours every day, only some of which will be AC-ed.

The answer would seem to be yes, we should switch. Given that the "old" machine is so good, I don't really expect a huge brand-new advantage, but it will be new, 3-star, hopefully more efficient, and could give us noticeable savings.

The only thing that worries me is disturbing a machine that is working superbly well. Taking things apart can mysteriously fix things... but it can also break them when they don't need fixing :)

What would people do?

Thanks. That's what our local engineer just told my wife :)

This is a worrying thing. Our engineer (local street guy) has recently seen two cases of new Daikin machines exploding. Serious damage. He put my wife completely off the brand :(.

Why would they happen? Is Daikin still premium... Or dangerous? :eek:

Have photo in WhatsApp. Will post when I go to PC.

Quote:

Originally Posted by Thad E Ginathom (Post 4371367)

Our engineer (local street guy) has recently seen two cases of new Daikin machines exploding.

Quote:

Originally Posted by Thad E Ginathom (Post 4371401)

Exploding AC --- Pictures[center]
Attachment 1742016

Seems to be a 2013 model ac from the compressor label. I had a Hitachi window ac blow up but not to this explosion level. The window ac was installed in a room with the outdoor on a balcony. This balcony was subsequently boarded up and as a result of the heat build up, it kind of exploded, room was filled with smoke. From the pictures can't really say what happened but is definitely scary.