Time to have my first A/C unit installed – looking for advice

[MrScratch]

For the first time ever I’m looking at having 2 A/C units installed in my house

 

The house electrical supply is prone to regular power cuts , voltage fluctuation and spikes ( 230V down to 195 Volts or lower ) . So from what I have read so far its probably best to steer clear of the Inverter type of A/C unit.

 

The house has a 30Amp electricity meter out in the street and a circuit breaker box in the lounge that has a 63 Amp main cut off / trip unit + a range of individual circuit breakers .

 

There are 2 spare 20 Amp un used circuit breakers in the circuit breaker box.

 

I have tried to use an online BTU calculator , but I can’t seem to get the same results , so can any one please have a look at my room dimensions and give me an idea of what size A/C units I will need for each room ( A and B )

 

Both rooms are bedrooms and the windows are normally left open and the outside walls get very hot to the touch both during the day time and night . The A/C will only normally be used at night time when the windows will be closed . The ceiling has no insulation above it and the loft area gets very hot.

 

Any advice or suggestions would be helpful before I visit an A/C shop to check out the price of each A/C unit and the installation cost .

 

 

Thanks

[Crossy]

The quick and dirty size calculation used here is 600-700 BTU per m².

 

Room A = 18m² = 10,800 - 12,600 BTU.

Room B = 14m² =  8,400 - 9,800 BTU.

 

As they are bedrooms you can keep to the lower end or go slightly smaller than that if there's a good deal.

 

With such lumpy power I too would avoid inverter units, it may also pay to use an AVR (Automatic Voltage Regulator).

 

Run one A/C off each of your spare breakers, run 2.5mm² x 3 core cable to the indoor unit location.

 

If you can get some shading on the outside walls, trees work well and look nice, you'll reduce the heat load significantly.

 

[bankruatsteve]

Yeah.  I would definitely go with Daikin "inverters" as close to the bottom of the range that you can get.  I'm of the opinion that the voltage "worry" for inverter units is based more on hyperbole than actual statistics (if there are any statistics).

 

And, if your voltage is really on a roller coaster, your equipment will be much happier with an AVR(AVS).

[Fruit Trader]

30 minutes ago, bankruatsteve said:

Yeah.  I would definitely go with Daikin "inverters" as close to the bottom of the range that you can get.  I'm of the opinion that the voltage "worry" for inverter units is based more on hyperbole than actual statistics (if there are any statistics).

 

And, if your voltage is really on a roller coaster, your equipment will be much happier with an AVR(AVS).

Daikin are currently promoting their products ability to resist power surges and lizards along with decent guarantee on the inverter control. I guess some other brands will be providing similar guarantee. I recently repaired a Mitsubishi inverter board where the L-N MOV was completely blown away along with most of the rectifier stage. 

[Fruit Trader]

My two cents would be provide double pole electrical isolation conveniently accessible near each unit. This allows disconnection of supply when not in use or away for long periods. It also provides easy isolation for cleaning and maintenance.

 

Air conditioner electronics left powered up on standby are open to power surges. Isolation will reduce the risk especially during storms.

 

Example local isolation switch ..

 

[sometimewoodworker]

4 hours ago, MrScratch said:

Both rooms are bedrooms and the windows are normally left open and the outside walls get very hot to the touch both during the day time and night . The A/C will only normally be used at night time when the windows will be closed . The ceiling has no insulation above it and the loft area gets very hot.

 

Any advice or suggestions would be helpful before I visit an A/C shop to check out the price of each A/C unit and the installation cost .

Installation will either be included or about 2,000 per unit. Painting the walls white if they are any other colour will probably reduce the temperature they get to by 10 degrees C, adding any kind of  installation on top of the ceilings will help.

 

if you get inverter units Crossy's numbers will be good and oversizeing is no problem. If you go for non inverters do not oversize as you won't be able to dehumidifie if they cool down the room too quickly.

[MrScratch]

7 hours ago, Crossy said:

The quick and dirty size calculation used here is 600-700 BTU per m².

 

Room A = 18m² = 10,800 - 12,600 BTU.

Room B = 14m² =  8,400 - 9,800 BTU.

 

As they are bedrooms you can keep to the lower end or go slightly smaller than that if there's a good deal.

 

With such lumpy power I too would avoid inverter units, it may also pay to use an AVR (Automatic Voltage Regulator).

 

Run one A/C off each of your spare breakers, run 2.5mm² x 3 core cable to the indoor unit location.

 

If you can get some shading on the outside walls, trees work well and look nice, you'll reduce the heat load significantly.

 

Thanks for the information , I’m going to check out the AVR thing , one area that I’m not sure about is the installation of the external out side A/C unit , from what Ive seen it looks like some units are mounted on wall brackets that lift the unit high up off the ground , the other option Ive seen is where the out side A/C unit sits on a floor mounting bracket or some sort of metal box frame .

 

 

Is it normal to request one of these types of mounting options when talking about the installation cost , and does any one type have an advantage. The other thing Ive noticed looking at other out side A/C units , is some have the pipe work enclosed in white / grey plastic trunking to hide it.

 

 

 

 

Again would that plastic trunking be an option to talk about when discussing the installation cost or would it normally included in the installation cost .

 

Just a thought , would these outside A/C units need some sort of water drain pipe work ?

 

 

 

 

[MrScratch]

6 hours ago, bankruatsteve said:

Yeah.  I would definitely go with Daikin "inverters" as close to the bottom of the range that you can get.  I'm of the opinion that the voltage "worry" for inverter units is based more on hyperbole than actual statistics (if there are any statistics).

 

And, if your voltage is really on a roller coaster, your equipment will be much happier with an AVR(AVS).

I keep seeing Daikin being recommended and yes the house voltage is like a roller coaster ride ☹️

 

[MrScratch]

6 hours ago, Fruit Trader said:

Daikin are currently promoting their products ability to resist power surges and lizards along with decent guarantee on the inverter control. I guess some other brands will be providing similar guarantee. I recently repaired a Mitsubishi inverter board where the L-N MOV was completely blown away along with most of the rectifier stage. 

I would be interested to learn from the A/C shop that I am planning to visit , what the warranty would be on the Daikin inverter control board.

[MrScratch]

6 hours ago, Fruit Trader said:

My two cents would be provide double pole electrical isolation conveniently accessible near each unit. This allows disconnection of supply when not in use or away for long periods. It also provides easy isolation for cleaning and maintenance.

 

Air conditioner electronics left powered up on standby are open to power surges. Isolation will reduce the risk especially during storms.

 

Example local isolation switch ..

 

 

Thanks for the advice , the double pole switch is now on my list . Just thinking about it , the power cuts , voltage fluctuation and spikes only seem to happen during the day time and never at night.

 

 

 

 

[MrScratch]

2 hours ago, sometimewoodworker said:

Installation will either be included or about 2,000 per unit. Painting the walls white if they are any other colour will probably reduce the temperature they get to by 10 degrees C, adding any kind of  installation on top of the ceilings will help.

 

if you get inverter units Crossy's numbers will be good and oversizeing is no problem. If you go for non inverters do not oversize as you won't be able to dehumidifie if they cool down the room too quickly.

Thanks , I was wondering about the installation costs , do the installation costs normally include installing the electrical cable from the circuit breaker board to the A/C unit .

 

[The Fat Controller]

It's the INSIDE unit that will have a condensate drain pipe, try to have as few bends as possible and keep it clean !

 

We have 2 Daikin inverter units, they are very quiet and reliable.

 

Outside units are mounted high on the walls under the eaves so they are out of the sun and rain, although a pair of pigeons decided to nest on one.

 

We purchased from Home Pro in their sale, their salesman did a site survey prior to us buying.

 

Fitting was included, the only extra was the plastic trunking, which was charged per metre.

 

Electrical cabling back to the board is unlikely to be included in the price unless agreed with the installer.

[sometimewoodworker]

7 hours ago, MrScratch said:

Thanks , I was wondering about the installation costs , do the installation costs normally include installing the electrical cable from the circuit breaker board to the A/C unit .

 

As the already been noted, no, but worth asking when you purchase.

[Thainesss]

14 hours ago, Crossy said:

The quick and dirty size calculation used here is 600-700 BTU per m².

 

Room A = 18m² = 10,800 - 12,600 BTU.

Room B = 14m² =  8,400 - 9,800 BTU.

 

If I was buying AC's id definitely stick to the high side of those figures, or even the next size up if its affordable if only for the extremely hot part of the year. If the sun exposed walls are hot to the touch and no ceiling insulation then IMO they are gonna really struggle. 

 

I guess it depends on what temps OP wants to see in those rooms, but Id hate to spend all that cash and be disappointed.

 

7 hours ago, MrScratch said:

Thanks for the advice , the double pole switch is now on my list . Just thinking about it , the power cuts , voltage fluctuation and spikes only seem to happen during the day time and never at night.

 

If you run the new AC's from their own breakers in the breaker panel you dont need these switches, or the wiring mess on the walls, as you can just switch the breaker itself.

 

The plastic conduit and wiring is usually extra (and kind of expensive), and the typical install price is around 2,000 - 2,500 baht per unit. If you dont use the plastic conduit then you'll have the same installation and instead of seeing the plastic, you'll see wrapped copper pipe fixed to the wall, just like your see here:

 

 

I have all 4 of my AC's mounted up high on the wall under the eaves of the roof to keep them shaded and off the ground so its easier to walk around. Mounting the outdoor unit on the ground costs nothing but the bracket to mount them on the wall is about 500 baht extra. 

 

I believe the length of copper piping included with the Aircon is 4 or 5 meters in length, meaning that the indoor unit and the outdoor unit can be about a max of 4 meters apart. Any farther and you'll have to pay extra for new copper pipe. 

 

AC brand favorability if extremely subjective, but I wouldn't buy ANYTHING other than Mitsubishi. Ive had good luck with Daikin but IMO the best Aircons BY FAR are Mitsubishi. 

[MrScratch]

7 hours ago, The Fat Controller said:

It's the INSIDE unit that will have a condensate drain pipe, try to have as few bends as possible and keep it clean !

 

We have 2 Daikin inverter units, they are very quiet and reliable.

 

Outside units are mounted high on the walls under the eaves so they are out of the sun and rain, although a pair of pigeons decided to nest on one.

 

We purchased from Home Pro in their sale, their salesman did a site survey prior to us buying.

 

Fitting was included, the only extra was the plastic trunking, which was charged per metre.

 

Electrical cabling back to the board is unlikely to be included in the price unless agreed with the installer.

Thanks for the info and advice , its appreciated

[MrScratch]

18 minutes ago, Thainesss said:

 

If I was buying AC's id definitely stick to the high side of those figures, or even the next size up if its affordable if only for the extremely hot part of the year. If the sun exposed walls are hot to the touch and no ceiling insulation then IMO they are gonna really struggle. 

 

I guess it depends on what temps OP wants to see in those rooms, but Id hate to spend all that cash and be disappointed.

 

 

If you run the new AC's from their own breakers in the breaker panel you dont need these switches, or the wiring mess on the walls, as you can just switch the breaker itself.

 

The plastic conduit and wiring is usually extra (and kind of expensive), and the typical install price is around 2,000 - 2,500 baht per unit. If you dont use the plastic conduit then you'll have the same installation and instead of seeing the plastic, you'll see wrapped copper pipe fixed to the wall, just like your see here:

 

 

I have all 4 of my AC's mounted up high on the wall under the eaves of the roof to keep them shaded and off the ground so its easier to walk around. Mounting the outdoor unit on the ground costs nothing but the bracket to mount them on the wall is about 500 baht extra. 

 

I believe the length of copper piping included with the Aircon is 4 or 5 meters in length, meaning that the indoor unit and the outdoor unit can be about a max of 4 meters apart. Any farther and you'll have to pay extra for new copper pipe. 

 

AC brand favorability if extremely subjective, but I wouldn't buy ANYTHING other than Mitsubishi. Ive had good luck with Daikin but IMO the best Aircons BY FAR are Mitsubishi. 

Thanks for the comment and advice , lifting the outside A/C unit up off the floor and installing it high up out of the sun light and rain sounds a good thing to do , where I live the house is surrounded by red earth fields and at some time a red dry dust can be seen in the wind and it tends to leave a coating of dust over things . Having the A/C units mounted high up will not look so attractive ( you will see the mounting brackets / frame ) as mounted directly on the floor , but may be its worth loosing some of the attractiveness for the extra benefits that high mounting would bring.

 

Never having A/C installed before I'm really not sure of what temperatures I would be happy with in each bedroom , the other thought is what sort of noise will each outside A/C unit generate , with them being close to the bedroom windows .

 

 

 

[mr_lob]

Been through countless LG's and Samsungs, all went in the bin over the years. Now we are running all Daikin in our resort and they are brilliant - no issues at all.

[Aforek]

29 minutes ago, mr_lob said:

Been through countless LG's and Samsungs, all went in the bin over the years. Now we are running all Daikin in our resort and they are brilliant - no issues at all.

I have a Daikin inverter, very good, silent and save money ; my neighbour has a LG, don't know if it's good, but from outside, it's noisy ( more than mine ) 

[sometimewoodworker]

1 hour ago, MrScratch said:

Thanks for the comment and advice , lifting the outside A/C unit up off the floor and installing it high up out of the sun light and rain sounds a good thing to do , where I live the house is surrounded by red earth fields and at some time a red dry dust can be seen in the wind and it tends to leave a coating of dust over things . Having the A/C units mounted high up will not look so attractive ( you will see the mounting brackets / frame ) as mounted directly on the floor , but may be its worth loosing some of the attractiveness for the extra benefits that high mounting would bring.

 

Never having A/C installed before I'm really not sure of what temperatures I would be happy with in each bedroom , the other thought is what sort of noise will each outside A/C unit generate , with them being close to the bedroom windows .

 

 

 

Pay for the extra length of pipe if you need to, it is a minimal amount, and mount the outdoor units away from the bedroom walls. I did with the ones in the new house and in the old house the 4 metres of included pipe was long enough, specially as both the units were mounted at the same hight. 

 

Though both indoor and outdoor units are quite quiet you will hear them at night so specifically because your bedroom walls will transmit sound quite well put the outside unit on a different wall.

 

As to attractiveness, do they ever look attractive? Also after a month or so you will stop seeing them wherever they are but if on the ground you may still find them in your way.

[Thainesss]

1 hour ago, MrScratch said:

Having the A/C units mounted high up will not look so attractive ( you will see the mounting brackets / frame ) as mounted directly on the floor , but may be its worth loosing some of the attractiveness for the extra benefits that high mounting would bring.

 

The brackets you pictured are some home made ones made out of cheap angle iron. The install shop will have some professional pieces that look better. 

I think they look better up on the wall and its easier to keep outside your house clean if they are off the ground. 

 

1 hour ago, MrScratch said:

Never having A/C installed before I'm really not sure of what temperatures I would be happy with in each bedroom , the other thought is what sort of noise will each outside A/C unit generate , with them being close to the bedroom windows .

 

The inside unit is louder in the room than the outside unit. My Mitsubishi units outside are extremely quiet just a little electric hum. 

 

What kind of normal temps at home do you like to sleep in? Not gonna be any different here. In Thailand I like about 20 C and use a down comforter to sleep. Some people on here like 29C to sleep (way to hot for me). 

 

Anyway you should be good with 9k BTU and 12k BTU units but if it was me I would buy the next size larger. 

[sometimewoodworker]

5 minutes ago, Thainesss said:

The brackets you pictured are some home made ones made out of cheap angle iron. The install shop will have some professional pieces that look better. 

Like these

[Fruit Trader]

10 hours ago, MrScratch said:

I would be interested to learn from the A/C shop that I am planning to visit , what the warranty would be on the Daikin inverter control board.

The info in my mail from Daikin TH

 

Super Inverter Models

 

5-years Warranty Inverter Compressor
3-years Warranty Inverter PCB
3-years Warranty Evaporator
3-years Warranty outdoor Condenser

[Thainesss]

3 minutes ago, Fruit Trader said:

The info in my mail from Daikin TH

 

Super Inverter Models

 

5-years Warranty Inverter Compressor
3-years Warranty Inverter PCB
3-years Warranty Evaporator
3-years Warranty outdoor Condenser

 

Yeah but how do you redeem these warranties? Thats always the problem. Not like the Daikin rep is gonna come out or the shop selling it to you has a certified daikin rep or handle warranties in any capacity.

 

Warranties in Thailand are about as valuable as the paper they are written on. 

[eero]

Make isolation in middelroof it is very cheap, and it will reduse your elecktrick bill.

I buy solarpanels (14pieces 4,2kw) on griff system and my bills are now 50% lower

Best Regards

Eero from Chaiyaphum

[Fruit Trader]

3 minutes ago, Thainesss said:

 

Yeah but how do you redeem these warranties? Thats always the problem. Not like the Daikin rep is gonna come out or the shop selling it to you has a certified daikin rep or handle warranties in any capacity.

 

Warranties in Thailand are about as valuable as the paper they are written on. 

I have no idea, just quoting what the Daikin literature says. Maybe call and ask about how the warranty is passed to installers. Make sense?

[Fruit Trader]

2 hours ago, Thainesss said:

If you run the new AC's from their own breakers in the breaker panel you dont need these switches, or the wiring mess on the walls, as you can just switch the breaker itself.

Yes that's right, its so much more convenient to isolate at the distribution panel compared to a locally mounted switch. Maybe that's why so many codes specify local isolation to make like more difficult.

[Thainesss]

3 minutes ago, Fruit Trader said:

I have no idea, just quoting what the Daikin literature says. Maybe call and ask about how the warranty is passed to installers. Make sense?

Warranties are not passed to the installers, thats my whole point. 

[Fruit Trader]

Just now, Thainesss said:

Warranties are not passed to the installers, thats my whole point. 

You appear to know half the story already so call Daikin and fill in the blanks. Make sense ?

[Thainesss]

1 minute ago, Fruit Trader said:

Maybe that's why so many codes specify local isolation to make like more difficult.

 

"Codes" dont specify local isolation for an air-conditioning. 

 

The reason they add those breakers on the wall is because they retro-fit the aircon and piggy back off the mains power. If there is an available breaker in the breaker box then you dont need a second wall mounted breaker. 

[Fruit Trader]

1 minute ago, Thainesss said:

Codes" dont specify local isolation for an air-conditioning. 

Oh yes they do. Fixed appliances bla bla bla.