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Old 13th August 2011, 08:17   #2161
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Originally Posted by khoj View Post
That is a neat looking piece and half a step in the right direction. A full step would be to install a servo stabilizer on to the house's mains so that all of the electrical/electronics in the house would benefit from stable input voltage. Just my thoughts.
@khoj, Yes you are right. The right idea is to install a servo piece (12 to 15kva) for the whole house. Such a stabilizer will occupy a size and space of a half-refrigerator. In my rented flat, the space is at a lil premium. So I did not bother to go for that.
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Old 13th August 2011, 11:38   #2162
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@khoj, Yes you are right. The right idea is to install a servo piece (12 to 15kva) for the whole house. Such a stabilizer will occupy a size and space of a half-refrigerator. In my rented flat, the space is at a lil premium. So I did not bother to go for that.
When we had only the ground floor built up and single phase supply, I too had put a 5KVA servo just after the electricity meter. That was sufficient for the whole house including one AC. Then BSES came and the voltage stabilised, so I got rid of it when we expanded and got 3 phase supply.

Where the voltage fluctuates, a servo stabilizer is the least expensive option (and the best too). It is best to pay more and get an industrial grade servo. These will keep going on and on. The only maintenance required is to inspect the "contact carbon brush" for wear once a year, and blow away the dust from the contact surfaces.

If you have 3 phase supply, it is better to get 3 individual servos rather than one 3 phase unit, as in domestic circuits the voltage varies phase to phase.
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Old 13th August 2011, 15:56   #2163
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Default Re: Which home/office AC (air conditioner) to buy ?

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If you have 3 phase supply, it is better to get 3 individual servos rather than one 3 phase unit, as in domestic circuits the voltage varies phase to phase.
That's interesting: I had always assumed that a three phase servo stabiliser would have independent control over each phase. As you say, they can be very far from equal.

It's been on my want-one list ever since moving to this house. If we had known then, how bad the current situation would be two or three years later, we would have included it in the house renovation.

As to increasing the electricity bill, it seems inevitable. There must be an overhead for the machine itself, which is probably small, but, the lower the voltage, the more current must be drawn to do the same work --- or to increase the voltage.

The volts/watts/amps formula probably provides the answer for the numerate, but my innumerate brain says that if I want to pump up 200v to 220v, I must draw around 10% more current from the main, and so my bill will be at least 10% more. My calculation is by analogy, not maths, so let not the engineers jump on me --- but the real calculation would be welcome

In this area, 200v is normal on a good day!
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Old 14th August 2011, 11:27   #2164
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The volts/watts/amps formula probably provides the answer for the numerate, but my innumerate brain says that if I want to pump up 200v to 220v, I must draw around 10% more current from the main, and so my bill will be at least 10% more. My calculation is by analogy, not maths, so let not the engineers jump on me --- but the real calculation would be welcome

In this area, 200v is normal on a good day!
Actually in some cases the more the voltage near the designed value the less current is drawn. For example at low voltages the motor may draw more current than at its designed voltage. In most of the cases especially with electronics there may not be appreciable power consumption deviation with voltage spread, as they have high efficiency switching power supplies converting the mains voltage to their operating voltage.

The only case where the power consumption increase is with heating elements (there fore incandescent bulbs also), but then you get more output.

As far as power consumption goes, lower voltage with higher current (at input) will equal higher voltage at lower current. As the utility meter measures power, boosting voltage should not increase power consumption. (OK there is a loss in a stabilizer, but that should be negligible compared to power delivered).
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Old 16th August 2011, 11:57   #2165
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Default Re: Which home/office AC (air conditioner) to buy ?

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Originally Posted by Thad E Ginathom View Post
That's interesting: I had always assumed that a three phase servo stabiliser would have independent control over each phase. As you say, they can be very far from equal.

It's been on my want-one list ever since moving to this house. If we had known then, how bad the current situation would be two or three years later, we would have included it in the house renovation.

As to increasing the electricity bill, it seems inevitable. There must be an overhead for the machine itself, which is probably small, but, the lower the voltage, the more current must be drawn to do the same work --- or to increase the voltage.

The volts/watts/amps formula probably provides the answer for the numerate, but my innumerate brain says that if I want to pump up 200v to 220v, I must draw around 10% more current from the main, and so my bill will be at least 10% more. My calculation is by analogy, not maths, so let not the engineers jump on me --- but the real calculation would be welcome

In this area, 200v is normal on a good day!
@Aroy has already made some comments, here are mine:


Power = voltage*current (it is a little more complicated than that, phasors come into picture, also known as power factor).

The "servo" is actually a variable transformer, for a 100% efficiency it will transfer as much power to your equipment as it receives from the mains. Most transformers achieve more than 90% efficiency, most large transformers achieve more than 99% efficiency. So for a first rough calculation 100% efficiency is good enough.

Now if you have a 1kW heater in the house rated at 220V, and you are using the SERVO (meaning the heater sees 220V irrespective of mains voltage) then the SERVO's current from mains will change - @200V it will draw 5A, at 220V it will draw 4.5A and at 180V it will draw 5.5A from the mains - all the while outputing 4.5A @220V to the heater.


As far as losses go, there will be core losses in the transformer, resistance losses in the coil (both have a cost-efficiency-heat tradeoff, but you can safely assume 2 to 5%, lower for better and heavier transformers) and motor losses for the servo mechanism - the latter will be insignificant if the voltage doesn't fluctuate all the time (most of the time the motor will not work)

For a good design you will have far less wastage than even a typical inverter will have - if the 5kVA assembly doesn't even have a fan to cool it then you can essentially neglect the losses.
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Old 16th August 2011, 14:33   #2166
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Default Re: Which home/office AC (air conditioner) to buy ?

Which home/office AC (air conditioner) to buy ?-hall-ac.jpg


guys, after all the advice obtained here i've decided to install 2 x 1.5 split ACs for my living hall which is 250 sq ft and has a kitchen attached which is 60 sq ft.

One will be a Heat and Cool model and the other will be a Cool only model. I'm confused as to where to install the Heat and Cool model.

My aim/target is to install the Heat and Cool model in such a location so that it can Cool the Kitchen in summers and Heat the Kitchen in winters.

Is this a achievable idea ? Can the Split AC have any effect on the Kitchen from 13 ft away ?

I'm attaching a diagram of my living room.

1. AC2 - is the location of the Cool only model.

2. A or B - is the location for the Heat & Cool model. I can consider a C option if anyone here has a better suggestion.

Looking for guidance as to where to install the Heat & Cool model so that it can service the Kitchen area too. All ideas are welcome.

Regards,

Rana

Last edited by rana_kirti : 16th August 2011 at 14:35.
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Old 16th August 2011, 17:54   #2167
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Default Re: Which home/office AC (air conditioner) to buy ?

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Originally Posted by rana_kirti View Post
Attachment 593586


guys, after all the advice obtained here i've decided to install 2 x 1.5 split ACs for my living hall which is 250 sq ft and has a kitchen attached which is 60 sq ft.

One will be a Heat and Cool model and the other will be a Cool only model. I'm confused as to where to install the Heat and Cool model.

My aim/target is to install the Heat and Cool model in such a location so that it can Cool the Kitchen in summers and Heat the Kitchen in winters.

Is this a achievable idea ? Can the Split AC have any effect on the Kitchen from 13 ft away ?

I'm attaching a diagram of my living room.

1. AC2 - is the location of the Cool only model.

2. A or B - is the location for the Heat & Cool model. I can consider a C option if anyone here has a better suggestion.

Looking for guidance as to where to install the Heat & Cool model so that it can service the Kitchen area too. All ideas are welcome.

Regards,

Rana
If you want to cool the kitchen, you may need more cooling power. If the kitchen has an exhaust fan and/or electric chimney a lot of cold air will be evacuated through the kitchen which while cooling the kitchen will afect the Living Room.

Location B is better for the living room, as the air will have to traverse the width of the room before going to the kitchen. In location A, there will be very little cooling on the side of location B.
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Old 16th August 2011, 18:50   #2168
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Default Re: Which home/office AC (air conditioner) to buy ?

Aroy,

a few added points for re-consideration...

1. the kitchen is used mostly from 8am to 12 noon and at that time no-one uses or is present in the living room.

2. the living room is used/occupied from 5pm to 11pm and at that time the kitchen is not used much other than for 15-20 mins to heat up dinner in the micro-wave.

3. So essentially the living room and the kitchen are never used together at the same time.

4. Infact the Kitchen will be guaranteed used from 8am to 12 noon but the living room might be not used everyday and only 2 or 3 times in a week.

5. Hence Cooling/Heating to reach the Kitchen is actually much more important to me than the living room. And then Living room also has the AC2 to help cool it better.

Considering the above i was wondering if the Location B would be a better idea to be able to Cool/Heat the Kitchen. What say ?

Regards,

Rana
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Old 16th August 2011, 19:19   #2169
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Default Re: Which home/office AC (air conditioner) to buy ?

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Originally Posted by rana_kirti View Post
Aroy,

a few added points for re-consideration...

1. the kitchen is used mostly from 8am to 12 noon and at that time no-one uses or is present in the living room.

2. the living room is used/occupied from 5pm to 11pm and at that time the kitchen is not used much other than for 15-20 mins to heat up dinner in the micro-wave.

3. So essentially the living room and the kitchen are never used together at the same time.

4. Infact the Kitchen will be guaranteed used from 8am to 12 noon but the living room might be not used everyday and only 2 or 3 times in a week.

5. Hence Cooling/Heating to reach the Kitchen is actually much more important to me than the living room. And then Living room also has the AC2 to help cool it better.

Considering the above i was wondering if the Location B would be a better idea to be able to Cool/Heat the Kitchen. What say ?

Regards,

Rana
In that case it is even better to have the AC as near the kitchen as possible. May be in line with AC2 near the kitchen entry. As long as the kitchen can be isolated (door?) the AC will not leak through the kitchen.
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Old 16th August 2011, 22:25   #2170
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Default Re: Which home/office AC (air conditioner) to buy ?

@rana_kirti

Let AC2 be where it is.

The heat and cool machine should be installed in the little niche next to the Kitchen door/entrance facing the same direction as AC2. The are next to (left) the arrow head towards the kitchen.

The 20 feet odd width will be easily covered by the two machines.
The 13 feet distance is a breeze for any air con to cover
The kitchen will benefit from the H&C machine as you intend it to.
Both machines on same wall will also allow for better aesthetics giving the room an uncluttered look.
The air currents will flow in the same direction leading to uniform air circulation and better conditioning of the area.
It will also be easy from installation view point in terms of piping etc going out of the same wall and will allow for outside units to be placed in a common area leading to ease of maintenance.

Position A is completely unsuitable as the wall on which the indoor unit will be hung is an internal wall and will lead to complications in terms of piping etc.

AC2 and B together are a basic no no for split install. This will lead to the air currents from the two machines on opposite walls mixing up and restricting each other from getting to the further end.
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Old 16th August 2011, 23:07   #2171
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Default Re: Which home/office AC (air conditioner) to buy ?

Which home/office AC (air conditioner) to buy ?-hall-ac-new.jpg

guys thanks for your suggestions. I have to further inform you that behind the "little niche next to the Kitchen door/entrance" is the Lift. So can't install the AC there. But i wonder does the piping of the Split AC always go behind the wall into which the Split AC is installed or can it be redirected front and then left or right. This actually might be dumb question on my part, but i guess it's still ok to ask

I have edited and re-posted the Picture.

I have also added a new Location C. This is on the right side of the little niche and is directly above the "Main Entry Door" of the house.

How do you think this will work out as far as kitchen getting benefit from the H&C machine ?

Regards,

Rana
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Old 17th August 2011, 00:01   #2172
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Default Re: Which home/office AC (air conditioner) to buy ?

C would be the second best location after the niche and yes kitchen will benefit.

As for the piping it can be taken out from behind, right or left of the Indoor unit.

To still use the niche, you may want to check the thickness of the lift wall. In case it is a 9" thick wall you may hang the unit on that wall in the niche just a couple of inches from the entrance door. the piping can go out through the wall to the right (facing the unit) out over the door and continue to wherever it is supposed to go. Now since the wall is an outer wall it should necessarily be a 9" and cutting a 2.5' ~ 3" channel through it for laying the pipes and the electric wire should not be an issue. the channel of course would be finished using cement plaster once the install is done and painted over thus retaining the finished 'look'.

The piping + wire + water drain pipe can continue to be concealed all the way up to machine AC2 and from that point on pipes for both machines could continue in a common external duct up to wherever it is that you wish to install the ODUs. The drain pipes too could travel in a separate and a smaller duct or common piping to the bottom of the wall to terminate in to a drain or a flower bed but certainly not on a neighbour's ledge/ hard floor/passage/common area etc.
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Old 17th August 2011, 00:06   #2173
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Default Re: Which home/office AC (air conditioner) to buy ?

Why not get one heat cool ac, and the second ac as one of those which has 2 indoor units. Place one in the kitchen and one in the living room. Use as and when needed.
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Old 17th August 2011, 13:12   #2174
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C would be the second best location after the niche and yes kitchen will benefit.

As for the piping it can be taken out from behind, right or left of the Indoor unit.

To still use the niche, you may want to check the thickness of the lift wall. In case it is a 9" thick wall you may hang the unit on that wall in the niche just a couple of inches from the entrance door. the piping can go out through the wall to the right (facing the unit) out over the door and continue to wherever it is supposed to go. Now since the wall is an outer wall it should necessarily be a 9" and cutting a 2.5' ~ 3" channel through it for laying the pipes and the electric wire should not be an issue. the channel of course would be finished using cement plaster once the install is done and painted over thus retaining the finished 'look'.

The piping + wire + water drain pipe can continue to be concealed all the way up to machine AC2 and from that point on pipes for both machines could continue in a common external duct up to wherever it is that you wish to install the ODUs. The drain pipes too could travel in a separate and a smaller duct or common piping to the bottom of the wall to terminate in to a drain or a flower bed but certainly not on a neighbour's ledge/ hard floor/passage/common area etc.
pardon me for sounding thick but i've tried pretty hard to picture the bolded part which you have tried to convey but i still can' fathom my mind around it. Could you re-phrase that part. Or if it's convenient can you re-edit the picture to demonstrate the same.

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Originally Posted by akshay1234 View Post
Why not get one heat cool ac, and the second ac as one of those which has 2 indoor units. Place one in the kitchen and one in the living room. Use as and when needed.
Main idea is to get the Kitchen to benefit from Heat Cool AC. if i can get by with just 2 units that will be great and the savings will go towards a Laura Vrs, but only if it comes with DSG
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Old 19th August 2011, 15:23   #2175
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@rana_kirti

It would be best if we were to talk. PM your contact number to me and I can call you in the evening.
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