Air Con experts please weigh in

[charleskerins]

Okay so I bought an 18,000 BTU AC    air con guy shows up (I hope he's an air con guy)      The front of the rental is a  hair salon which  has  a 12,000 BTU over the glass sliders entrance and  has it's own 30 amp breaker.  So I wanted to replace the 12,000 with the 18,000 .   The salon owner my friend wants the guy to put the 18,000 BTU where the 12,000 BTU  is and put the 12000 in the back room (bedroom and bathroom)  this area is extremely small but gets the afternoon sun on the roof very hot.  The AC guy (hopefully) and salon owner had lengthy discussion and they decided to put the 18000 on the back of the rental to cool the small bedroom.  they are going to leave the 12000 unit intact.I asked 4 times in English is there enough power to run two    the response was yes.   I await your intelligent non condemning input.. Price for the job 2500 THB

[lom]

3 minutes ago, charleskerins said:

I await your intelligent non condemning input..

What's the question?

[scubascuba3]

What's the question?

[IvorBiggun2]

1 minute ago, lom said:

What's the question?

 

6 minutes ago, charleskerins said:

I asked 4 times in English is there enough power to run two    the response was yes.

Are they lying?

[charleskerins]

28 minutes ago, IvorBiggun2 said:

 

Are they lying?

Oh questions        I don't know if they are lying I don't speak Thai    

                             how many amps are needed to run 2?

                            the bathroom has those vented blocks  I'm guessing that will waste ac ?  Should I close them off or is that their idea of a vent pipe?

[Moonlover]

Why not just leave it to them? They have a lot more experience than you, or, I suspect any of us have.

 

As far as the vented blocks in the bathroom are concerned, bathrooms need ventilation to prevent  condensation and dampness. My advise is leave well alone.

[lom]

42 minutes ago, charleskerins said:

how many amps are needed to run 2?

around 20 amps when they consume at most

[lom]

44 minutes ago, charleskerins said:

the bathroom has those vented blocks  I'm guessing that will waste ac ?

yes so keep the bathroom door closed

[Crossy]

6 minutes ago, lom said:

around 20 amps when they consume at most

 

Probably less than that in reality (closer to 15A tops), and once rooms are down to temperature ...

 

[Lee65]

If you want Thais to install the 18k BTU unit in the large room, tell them you want it in the small room.  

[charleskerins]

35 minutes ago, lom said:

around 20 amps when they consume at most

Thanks 

21 minutes ago, Lee65 said:

If you want Thais to install the 18k BTU unit in the large room, tell them you want it in the small room.  

 

21 minutes ago, Lee65 said:

If you want Thais to install the 18k BTU unit in the large room, tell them you want it in the small room.  

 

[charleskerins]

30 minutes ago, Crossy said:

 

Probably less than that in reality (closer to 15A tops), and once rooms are down to temperature ...

 

so they were right it's enough thanks!

[charleskerins]

1 hour ago, Moonlover said:

Why not just leave it to them? They have a lot more experience than you, or, I suspect any of us have.

 

As far as the vented blocks in the bathroom are concerned, bathrooms need ventilation to prevent  condensation and dampness. My advise is leave well alone.

I am just wanted to make sure there was enough power

[Moonlover]

5 minutes ago, charleskerins said:

I am just wanted to make sure there was enough power

 

1 hour ago, charleskerins said:

the bathroom has those vented blocks  I'm guessing that will waste ac ?  Should I close them off or is that their idea of a vent pipe?

This was your other question wasn't it?

[stubuzz]

You didn't mention the wire size and run length.

[transam]

1 hour ago, Moonlover said:

Why not just leave it to them? They have a lot more experience than you, or, I suspect any of us have.

 

As far as the vented blocks in the bathroom are concerned, bathrooms need ventilation to prevent  condensation and dampness. My advise is leave well alone.

I would block them off and install a wall fan to turn on when using the shower. Those vents are old school and invite all the creepy crawlies, mozzies etc..........🤗

[stoner]

1 hour ago, charleskerins said:

 I don't know if they are lying I don't speak Thai

 

if i was you i would learn thai as soon as possible. avoid things like this all together. 

[OneMoreFarang]

2 hours ago, charleskerins said:

30 amp breaker

More than enough for 3ACs of that size.

[BKKKevin]

The AC techs may be reticent to move the old AC... If it's old or a cheap brand they know there's a risk that in moving it they may damage it to the point it may not work... And they will most likely not get paid... 

[xtrnuno41]

 

6000 BTU    9000 BTU   12.000 BTU  20.000 BTU

1,76 kW         2,64 kW      3,52 kW        5,86 kW

 

So a 18000 BTU comes to 5,275 kW, calculated by interpolation.

Together on max cooling from both and on one breaker 5,275 + 3,52 =  8,795 kW = 8795 W

Small one 3520/230 = 15A, big one 5275/230 = 23 A, total 15+23 = 38 A

8795 W/ 230 V = 38 A.

Breaker reacts and switches off. This is when BOTH airco's are running on their top, full cooling at the same time. 

But also later in working time, fuse can switch off.

Especially when airco's are kicking in, you will have spikes in power, which also can effect the fuse.

 

Put the little one on a group of 20 A, which isnt used that much in Amps. If you have.

Time to find out what is on your groups and which one is not that loaded.

No clue how many fuses you have and their values.

Of course also to know what device is there, on what fuse.

It is not handy when you put the airco on a group with your refrigerator.

If something is wrong with the airco, the fuse will shut off and also refrigerator. That could be a waste.

Leave the big one on the 30 A only.

Of course also not handy to put it on the fuse for a shower heater, as both are big users and you ll have the same problem.

 

You can replace the 30A to 40 A, but maybe with spikes it could do the same.

All though most fuses in Thailand are C characteristic fuses and are slower in switching then a B type. 

 

OF course if you have the space in your fuse box, you can add a new one to it for the little one of 20 A.

But that takes some more effort, time, money.

 

It doesnt make sense to put a big airco in a small area for bedroom and shower.

The saloon is bigger? So needs a good capacity working airco.  Also for customers nice and for the working persons.

Why you first want to swap and then rethink? Is 12000 btu enough for saloon? So then it would be as well for the bedroom, why you use  a bigger one there then? Why you need bigger then after all, you could have bought another 12000 BTU one.?!

But ok thats up to you. 

 

 

 

 

 

 

 

 

 

[charleskerins]

2 hours ago, stubuzz said:

You didn't mention the wire size and run length.

Nope i didn't and i know that's important -it will be a short run less than 10 feet  don't know the wire size

[charleskerins]

32 minutes ago, xtrnuno41 said:

 

6000 BTU    9000 BTU   12.000 BTU  20.000 BTU

1,76 kW         2,64 kW      3,52 kW        5,86 kW

 

So a 18000 BTU comes to 5,275 kW, calculated by interpolation.

Together on max cooling from both and on one breaker 5,275 + 3,52 =  8,795 kW = 8795 W

Small one 3520/230 = 15A, big one 5275/230 = 23 A, total 15+23 = 38 A

8795 W/ 230 V = 38 A.

Breaker reacts and switches off. This is when BOTH airco's are running on their top, full cooling at the same time. 

But also later in working time, fuse can switch off.

Especially when airco's are kicking in, you will have spikes in power, which also can effect the fuse.

 

Put the little one on a group of 20 A, which isnt used that much in Amps. If you have.

Time to find out what is on your groups and which one is not that loaded.

No clue how many fuses you have and their values.

Of course also to know what device is there, on what fuse.

It is not handy when you put the airco on a group with your refrigerator.

If something is wrong with the airco, the fuse will shut off and also refrigerator. That could be a waste.

Leave the big one on the 30 A only.

Of course also not handy to put it on the fuse for a shower heater, as both are big users and you ll have the same problem.

 

You can replace the 30A to 40 A, but maybe with spikes it could do the same.

All though most fuses in Thailand are C characteristic fuses and are slower in switching then a B type. 

 

OF course if you have the space in your fuse box, you can add a new one to it for the little one of 20 A.

But that takes some more effort, time, money.

 

It doesnt make sense to put a big airco in a small area for bedroom and shower.

The saloon is bigger? So needs a good capacity working airco.  Also for customers nice and for the working persons.

Why you first want to swap and then rethink? Is 12000 btu enough for saloon? So then it would be as well for the bedroom, why you use  a bigger one there then? Why you need bigger then after all, you could have bought another 12000 BTU one.?!

But ok thats up to you. 

 

 

 

 

 

 

 

 

 

Salon is bigger 12000 doesn't get in done        first thought was to put the 18000 in the salon      only the very front of the salon   cools down      the rest of the place especially the bedroom is sweltering    of course i also have to hear it will only be for 2 months more than it will rain and we won't need the air con   I bought it  !

[charleskerins]

1 hour ago, BKKKevin said:

The AC techs may be reticent to move the old AC... If it's old or a cheap brand they know there's a risk that in moving it they may damage it to the point it may not work... And they will most likely not get paid... 

it's 12 years old samsung

[charleskerins]

2 hours ago, transam said:

I would block them off and install a wall fan to turn on when using the shower. Those vents are old school and invite all the creepy crawlies, mozzies etc..........🤗

fan would be better

[xtrnuno41]

1 hour ago, charleskerins said:

Salon is bigger 12000 doesn't get in done        first thought was to put the 18000 in the salon      only the very front of the salon   cools down      the rest of the place especially the bedroom is sweltering    of course i also have to hear it will only be for 2 months more than it will rain and we won't need the air con   I bought it  !

OK, so you agree, but then you should put the big one in the saloon, as the little one doesnt cope.

Yes, maybe 2months later you dont need, but next year then? Or in between very hot days? You will have the same problem.

But it is up to you

 

[Fruit Trader]

2 hours ago, xtrnuno41 said:

6000 BTU    9000 BTU   12.000 BTU  20.000 BTU

1,76 kW         2,64 kW      3,52 kW        5,86 kW

 

So a 18000 BTU comes to 5,275 kW, calculated by interpolation.

Together on max cooling from both and on one breaker 5,275 + 3,52 =  8,795 kW = 8795 W

Small one 3520/230 = 15A, big one 5275/230 = 23 A, total 15+23 = 38 A

8795 W/ 230 V = 38 A.

 

You have converted BTU (cooling capacity) to the equivalent energy in watts and used the result to calculate electrical power which is incorrect.

 

Work performed in watts is not the same as the power required in watts to do that work. Example :- AC capacity = 12,500 BTU/h approx electrical power required to achieve this capacity = 1000 watts 
 

[Guderian]

I had two Daikin AC units some years ago, 12 KBTU and 18 KBTU, like the OP. From what I recall, the power rating on the compressor plates were around 1 KW for the 12 KBTU unit and 1.5 KW for the 18 KBTU one, a total of 2.5 KW. So with a 220V supply you'd need about 12 A, though that may be the average load and the peak might be higher, but your 30A breaker is more than enough unless I'm missing something.

[zoltannyc]

According most electrical codes circuit breakers are primarily installed to protect the wire. It functions by interrupting the flow of electricity in a circuit when it detects an overload or a short circuit, preventing the wire from overheating and potentially causing a fire. However, by protecting the wire, it indirectly also helps to safeguard the connected appliances and devices from damage or malfunction.
 

For the wire:
For a copper wire with thermoplastic insulation (e.g. PVC) of 2.5 sq.mm, the ampacity rating is typically around 20-24 amps.
As a general rule, the circuit breaker rating should not exceed 80% of the wire ampacity to prevent overloading the wire.
80% of 20-24 amps is 16-19.2 amps.
Therefore, the closest standard circuit breaker size for a 2.5 sq.mm wire on a 220V circuit would be 15 amps.

 

For a copper wire with thermoplastic insulation (e.g. PVC) of 4 sq.mm, the ampacity rating is typically around 32 amps.
As a general rule, the circuit breaker rating should not exceed 80% of the wire ampacity to prevent overloading the wire.
80% of 32 amps is 25.6 amps.
Therefore, the closest standard circuit breaker size for a 4 sq.mm wire on a 220V circuit would be 25 amps.

 

For the AC:
According to EU standards a 12000BTU inverter AC needs a C10 circuit breaker and 18000BTU inverter a C16 circuit breaker.

In conclusion if you have proper wire and run two of the above ACs on a 30A circuit breaker there should be no problem.

Lastly: Fruit Trader is correct cooling capacity and drawn power are not the same, many of the calculations are incorrect.
 

[xtrnuno41]

On 4/30/2024 at 5:43 PM, Fruit Trader said:

 

You have converted BTU (cooling capacity) to the equivalent energy in watts and used the result to calculate electrical power which is incorrect.

 

Work performed in watts is not the same as the power required in watts to do that work. Example :- AC capacity = 12,500 BTU/h approx electrical power required to achieve this capacity = 1000 watts 
 

Yes, you are right. I made a big mistake as thinking the power was for electricity.

I searched for electric power of the airco's due to BTU but was fooled, should have been more awake.😴

Thanks for correcting, letting me know and sorry to members. 😔