Adding Air Conditioner To Room

[tangoll]

Hi, I have a question about adding a small 9,000 BTU split unit air con to an room which already has a larger aircon unit (about 18,000 BTU) cassette type installed in the ceiling but the existing unit is very loud at night when it's on during sleep, even at low fan. The new A/C fan unit can be installed on the wall next to balcony and the condenser unit can be installed in the balcony which has a drain. My question concerns the electrical line. Can I just plug the line from the fan unit into a 2 pin plug socket normally used for a TV or floor lamp, or does the line have to go direct to a spare breaker/line at the switch box? What if there are no more spare lines at the main switch box? Does the condenser unit need its own electrical line/plug?

The new A/C unit I'm thinking of getting is a Samsung inverter unit which I am told at low fan is only about 19 decibels, which is the lowest amongst the brands normally handled by Homepro -- Mitsubishi, LG, Hitachi, Panasonic, Daikin, etc. I would only use the new unit during sleep, and even though small in BTU, should be sufficient to keep the room cool at night.

It would not really be practical to change the existing cassette type unit in the ceiling.

Edited June 10, 2010 by tangoll

[Pib]

If it's the 9000 BTU shown at this web page, it will only need 220V, 50Hz, Single Phase (i.e., standard outlet power) at 4 amps max when operating. split type air conditioner - AS09VBL - Split Type - Air Conditioner | SAMSUNG

If I had to guess, estimate your current A/C draws about 8 amps when the compressor and indoor unit are both operating.

Above mentioned 4 amp drawage is well within the current max of a typical electrical outlet (not to imply the overall circuit that outlet is on could handle another 4 amps). A microwave when operating/heating up your TV dinner pulls about 8 amps and you plug a home microwave into a regular outlet which is normally rated for 16 amps max, not to imply you could pull 16 amps from each outlet due to circuit breaker/wiring limitations. Since each outlet go to circuit breaker XYZ in your Main Electrical Box you will need to see what circuit breaker is rated for powering that particular outlet and try to figure out how much current is already typically running on the circuit from lights, TV, frig, things plug into other outlets using the same circuit breaker. Most circuit breakers for typical outlets are rated at 20 amps (but I've seen them at 16, 10, or 5 amps also). Now if you are sometimes already pulling say 17 amps on that circuit XYZ from a bunch of electrical items turned on, when your new A/C kicks in and adds its 4 amps for a total of 21 amps your circuit breaker is going to trip.

So, it the A/C system you are talking about is the one in above link, it "probably" can be wired/plugged into a typical outlet but you need to do some research on the circuit breaker powering the outlet and how much amperage that circuit could possibly be tasked with from other items plugged into the same circuit and turned on at the same time.

[richardt1808]

Hi,

Any person with even a basic electrical knowledge would tell you that this is a very bad and unsafe idea.

1. Most sockets in Thailand are not wired with an earth

2. The breakers on most older buildings are not always in a good condition

3. Although the AC may run on fairly low power, but when the compressor kicks in, it is likely to draw a significantly higher load way in excess of the current rating.

In any case, installation is free with new aircons, which includes running a separate circuit from the distribution box, so why on earth would you want to cut corners ?

[longball53098]

What the AC installers typically will do is to tap in to an already existing circuit and run the cable to a combination switch/breaker that will be fixed to the wall close to the indoor unit and power the system in this manner. No need to go all the way back to the breaker box and they never use the earth connections unless they are forced to by the buyer and then they may charge extra for the work and wire. Most of these guys could not give a hoot about the load on any breaker or line. Its up to you the buyer to spec exactly what you want and how it should be done. If the requirement by you is more than they would usually do then you will be charged more for the install.

[Pib]

What the AC installers typically will do is to tap in to an already existing circuit and run the cable to a combination switch/breaker that will be fixed to the wall close to the indoor unit and power the system in this manner. No need to go all the way back to the breaker box and they never use the earth connections unless they are forced to by the buyer and then they may charge extra for the work and wire. Most of these guys could not give a hoot about the load on any breaker or line. Its up to you the buyer to spec exactly what you want and how it should be done. If the requirement by you is more than they would usually do then you will be charged more for the install.

This combination switch/breaker prevents the A/C from drawing more than it should, but it's still tapped into a circuit/line going to a circuit breaker. Depending on how much the circuit/line is already drawing before the addition of the A/C load the A/C could continuely trip the circuit breaker in the main circuit breaker box without ever tripping the A/C switch breaker. Ex: The A/C uses a 10 amp switch/breaker and is tapped into a 20 amp home circuit already loaded to say 17 amps from the frig, microwave, lights, TV, etc. Turn on the new 4 to 8 amp A/C added to the circuit (with it's 10 amp breaker) and the main panel circuit breaker trips becauses more than 20 amps is being pulled on that circuit. But the 10 amp A/C switch/breaker never tripped because the A/C was pulling normal 4 to 8 amps.

Big 10-4 about how most installers won't give a hoot about the total load being pulled on a circuit as long as they can get the A/C to work.

[longball53098]

Oh I understand the pitfalls that is why I'm commenting about how the AC installers would do it without being told something specific. My post was for the OP to see that this is how it would be done. If he can identify a specific circuit then they could do it with the added breaker/switch and no need for a plug in.

[Pib]

After reading our advice/posts, the OP will probably just buy a battery-powered fan. Cheers.

[tangoll]

Thanks for all the replies and advice. I would like to be able to have a line go direct from the fan unit to the circuit breaker box, but the distance is about 10 meters and the line cannot really be concealed inside the walls, so quite unsightly if done that way. I guess for the time being, I will just have to suffer the noise from the cassette type A/C unit.

[PattayaParent]

^run the cable through your suspended ceilings to the DB.