What could cause BTU of a/c difference?

[agg211]

I want to place an a/c in my room which measures 6 x 4 meters (24 square meters) which is about 260 square feet. The height of the room is 2.5 meter.

At a big specialized shop they recommended 18000 btu for this room.

When I did a calculation myself on a few websites, including the details of the room (sunlight etc.) it gave me a result between 10000 and 13000 btu.

What could cause this difference?

[UWEB]

29 minutes ago, agg211 said:

I want to place an a/c in my room which measures 6 x 4 meters (24 square meters) which is about 260 square feet. The height of the room is 2.5 meter.

At a big specialized shop they recommended 18000 btu for this room.

When I did a calculation myself on a few websites, including the details of the room (sunlight etc.) it gave me a result between 10000 and 13000 btu.

What could cause this difference?

Big or small size Windows in, Ceiling Insulation, outside Walls exposed to Sunshine?

[Will B Good]

34 minutes ago, agg211 said:

I want to place an a/c in my room which measures 6 x 4 meters (24 square meters) which is about 260 square feet. The height of the room is 2.5 meter.

At a big specialized shop they recommended 18000 btu for this room.

When I did a calculation myself on a few websites, including the details of the room (sunlight etc.) it gave me a result between 10000 and 13000 btu.

What could cause this difference?

 

Greater profit on the larger a/c unit I imagine.

[agg211]

5 minutes ago, UWEB said:

Big or small size Windows in, Ceiling Insulation, outside Walls exposed to Sunshine?

 

On the websites I filled in specific information whereas at the shop they had standardized the btu depending on the size of the room: 22 - 26 square meters would require 18000 btu, no further questions asked.

 

Actually, does it really make a lot of difference, let's say 12000 or 18000 btu?

[CharlieH]

I have this in my bedroom, whilst a smaller 12k may work it will work harder.The 18000 handles it easily and therefore more efficiently and more cost effective in my opinion.

[Will B Good]

1 minute ago, CharlieH said:

I have this in my bedroom, whilst a smaller 12k may work it will work harder.The 18000 handles it easily and therefore more efficiently and more cost effective in my opinion.

 

Yes.....if in doubt........ go large.....no point in skimping on something like a/c.....it has to work as you wanted it to or it's money down the drain.

[OneMoreFarang]

Many calculators are from AC companies, and it seems they like to give you a reason to buy a bigger model.

 

In my experience the size of the room is less important than the windows size and especially the where the windows are. Big windows with direct sunlight are what heats up the room.

 

What I didn't find on any calculator is what temperature you want and when. Do you want to cool down your room to 24 degrees or 20 degrees? And do you want to have the low temperature in the middle of the day when the sun is shining in your window or only at night when it's a lot cooler outside?

[JBChiangRai]

Some of the brands only charge about 1,500 baht more for 18,000 BTU.

 

TCL Inverter 18,000 BTU on sale for 10,022 baht on Lazada.

 

I have 6 of this unit in my house and 7 others.  It’s a great, very quiet unit.

 

 

[agg211]

23 minutes ago, JBChiangRai said:

Some of the brands only charge about 1,500 baht more for 18,000 BTU.

 

TCL Inverter 18,000 BTU on sale for 10,022 baht on Lazada.

 

I have 6 of this unit in my house and 7 others.  It’s a great, very quiet unit.

 

 

 

And what were the installment costs per unit?

[JBChiangRai]

Lazada did offer an installment option, I used our own guys.

 

You should budget 2,000-3,500 baht for installation.

[GammaGlobulin]

4 hours ago, CharlieH said:

I have this in my bedroom, whilst a smaller 12k may work it will work harder.The 18000 handles it easily and therefore more efficiently and more cost effective in my opinion.

 

As I have mentioned in the past.

 

Efficiency data is provided by the manufacturer, and is unique to each AC design.

 

I always buy a machine with at least a SEER of 24.

 

It matters not, to efficiency, what size you buy....except higher-efficiency units are not the large ones, but somewhere between 9000 BTU and 18,000 BTU.  Larger than that, and its more difficult to design a machine which can score about a SEER of 24.

 

===========

 

After buying the AC, then one can lower operating costs by adding insulation, by ensuring that the outdoor unit does not get hit by direct sunlight, and that the outdoor unit is placed so that it will get proper ventilation from the condenser-unit fan.

 

Also, just for my bedroom, I use a 24,000 BTU unit, even though my bedroom is rather small, by my standards.

 

Finally, if one wishes to oversize the choice of AC unit, then be sure to choose a unit which is a true inverter design.  This way, the inverter can supply a range of BTU-cooling during operation.  The compressor will then run more slowly when needed, and faster when needed.  This is NOT true for a non-inverter design which just turns on and then off, but is unable to vary the speed of the compressor.

 

It's rather simple really.

All the info needed is on the net.

 

As to which brand is the best in Thailand?

I have no clue, and maybe most are not as good as the same brands when sold to the Japanese market, for example.

 

However, the actual compressors used in the Panasonic brands seem to be the same, no matter what the market might be.

Therefore, the Panasonic compressor, meaning the actual compressor and not the compressor unit with a possible problem fan, is quite good, and I think excellent, actually.

It's only when the compressor is assembled with potential problem components, such as a defective fan, or thermostat, etc, that there may be a problem.  But, I will not say, since I have never bought like 500 units, so that I could get a good samples size, large enough to draw some informed conclusion.

 

In Conclusion:  Choose a unit with a SEER of at least 24.  And choose a premium brand.  And choose an Inverter design, for sure.

 

Then, after one has done all this....It's in God's hands, from there on out.

 

 

 

 

 

[KannikaP]

3 hours ago, JBChiangRai said:

Lazada did offer an installment option, I used our own guys.

 

You should budget 2,000-3,500 baht for installation.

I paid Bht 2000 for fitting new TCLs, and the fitter gave me Bht 1000 for the 12 year old Mitsus. Nice.

[scubascuba3]

29 minutes ago, KannikaP said:

I paid Bht 2000 for fitting new TCLs, and the fitter gave me Bht 1000 for the 12 year old Mitsus. Nice.

Probably depends where you live, in Pattaya i had quotes of 3k to 4k, including 500 baht for removal

[arick]

On 1/4/2025 at 11:05 AM, agg211 said:

I want to place an a/c in my room which measures 6 x 4 meters (24 square meters) which is about 260 square feet. The height of the room is 2.5 meter.

At a big specialized shop they recommended 18000 btu for this room.

When I did a calculation myself on a few websites, including the details of the room (sunlight etc.) it gave me a result between 10000 and 13000 btu.

What could cause this difference?

A 25 square room with 2 m ceilings all you need is even a good 9,000 not more than 11,000

[arick]

On 1/4/2025 at 5:16 PM, scubascuba3 said:

Probably depends where you live, in Pattaya i had quotes of 3k to 4k, including 500 baht for removal

It's only 1300 to have an ac fitted. When you purchase the fitting online when buying the air-conditioner. 

[arick]

TCL is the best for cooling. Bought 2 24,000btu @ 13999.00bht. works great very cold. .uch better then other makes. 

[AndreasHG]

On 1/4/2025 at 12:34 PM, agg211 said:

And what were the installment costs per unit?

 

The installation cost is not significantly affected by the size of the unit. It varies based on the complexity of the installation (pipe length, finish, etc.).

 

Regarding the cooling capacity, shops usually do not take any risks and recommend the capacity required in the worst possible scenario (large windows, south facing, exposed to direct sunlight, poor insulation, daytime operation, etc.).

 

f your room does not have such extreme conditions, it is better to choose a unit with a lower capacity.

Oversizing the unit attenuates or negates the benefits of the inverter. Each inverter operates within a certain range around its rated capacity (e.g. 30% to 110%). 
If the nominal capacity of the unit is too high and the typical heat load is close to the minimum capacity of the inverter, the unit does not modulate but operates as an On/Off unit, turning the compressor on and off instead of slowing it down.

 

Don't buy Chinese stuff. Choose renowned brands (Mitsubishi Electric, Daikin, Carrier, Toshiba and Panasonic). 

The best inverter units (those which can provide the highest comfort and energy efficiency) are those with the widest modulation range. Some of these brands' top of the line units are equipped with twin rotary compressors, capable of rotating at a very wide range of RPM, without emitting excessive vibrations.

The advantages offered by a good inverter (wide RPM range) are numerous: the continuous and regular operation of the compressor improves the thermal comfort, the energy efficiency, reduces the mechanical and thermal stress on the AC components boosting its reliability, and reduces the noise.

 

Cheap inverters units (in name only) have narrow modulation ranges (e.g. 70%-100% of the nominal capacity). They are marketed as inverters, but they actually behave most of the time as cheap fix-speed units, continuously switching their compressor On and Off to regulate the temperature.

 

 

[JBChiangRai]

2 hours ago, AndreasHG said:

 

Don't buy Chinese stuff. Choose renowned brands (Mitsubishi Electric, Daikin, Carrier, Toshiba and Panasonic). 

The best inverter units (those which can provide the highest comfort and energy efficiency) are those with the widest modulation range. Some of these brands' top of the line units are equipped with twin rotary compressors, capable of rotating at a very wide range of RPM, without emitting excessive vibrations.

The advantages offered by a good inverter (wide RPM range) are numerous: the continuous and regular operation of the compressor improves the thermal comfort, the energy efficiency, reduces the mechanical and thermal stress on the AC components boosting its reliability, and reduces the noise.

 

Cheap inverters units (in name only) have narrow modulation ranges (e.g. 70%-100% of the nominal capacity). They are marketed as inverters, but they actually behave most of the time as cheap fix-speed units, continuously switching their compressor On and Off to regulate the temperature.

 

 

 

This is nonsense.

[KannikaP]

13 minutes ago, JBChiangRai said:

 

This is nonsense.

Agree. Changed my 6 x 12 year old Mitsus for TCL Inverters with WiFi, very good price on Lazada when 10/10 or 11/11 sales are on. 12000s for the bedrooms, and 2 x 12000 for the big lounge.

OK, let's see if they go 12 years with no problems, but at the moment they are so much cooler, quieter and more efficient. 

 

[AndreasHG]

2 hours ago, JBChiangRai said:

 

This is nonsense.

 

Your comment is nonsense. Are you really so naive as to believe that all inverter air-conditioners are the same, just because the manufacturers print an "Inverter" label on their boxes?

 

You always get what you pay for. And TLC units are among the cheapest units you can buy, also when comparing its prices only with Chinese competitors. That's it.

 

[AndreasHG]

2 hours ago, KannikaP said:

Agree. Changed my 6 x 12 year old Mitsus for TCL Inverters with WiFi, very good price on Lazada when 10/10 or 11/11 sales are on. 12000s for the bedrooms, and 2 x 12000 for the big lounge.

OK, let's see if they go 12 years with no problems, but at the moment they are so much cooler, quieter and more efficient. 

 

It would have been notable if the brand-new TLC inverter units had not performed better than the 12-year-old fixed speed MELCO units.

Try comparing any 12 years old Toyota diesel pick-up truck with any brand-new electric car and see if you get a different result.

 

[JBChiangRai]

56 minutes ago, AndreasHG said:

 

Your comment is nonsense. Are you really so naive as to believe that all inverter air-conditioners are the same, just because the manufacturers print an "Inverter" label on their boxes?

 

You always get what you pay for. And TLC units are among the cheapest units you can buy, also when comparing its prices only with Chinese competitors. That's it.

 

I think you mean TCL, TLC is an acronym for tender loving care.

 

Just because something is cheaper doesn’t mean it is worse. The Chinese have disrupted the air-conditioning market in Thailand, TCL is now the market leader on Lazada for air-conditioning units.

 

Why would you pay double or treble the 10,088 baht price for a TCL 18,000 BTU unit to get a Thai or Japanese unit which is no better.

 

Our company has installed well over 100 A/C units in our new builds and for the last 4 years TCL is our brand of choice.  Zero failures, No yellowing.  People say Daikin are good, we have a 40% failure rate in 6 years on their inverter units and they yellow horribly, as does Mitsubishi.

 

Chinese BYD is the market leader for electric cars and according to the engineers commissioned by UBS, the cars are cheaper, equivalent quality and a generation ahead of their German electric rivals, with a far higher degree of integration.

 

Cheaper does not automatically mean inferior.

 

 

[AndreasHG]

48 minutes ago, JBChiangRai said:

Our company has installed well over 100 A/C units in our new builds and for the last 4 years TCL is our brand of choice.

 

Thak you for being honest. I immediately understood you had a vested interest in promoting TCL, but I had no evidence to support my assumption.

 

I have no vested interest. I am not in the AC business, and I am not a shareholder of any of the companies I mentioned above. 

 

My recommendation to the readers herewith is, if they really care about quality, to stay clear of Chinese designed and made units, including TCL.

 

To you my recommendation is to introduce a two-or-three-tiers offering, something the like of good, better, and best. The Thai market is maturing. Customers are getting more experienced, and they start appreciating differences that first time users do not appreciate.

 

If you don't see the need to expand your company offering to include also upmarket solutions now, you may soon. Actually, for your company, it may become a matter of survival, when the market finally really becomes mature. I have seen this trend in Japan first, in Europe thereafter, and in Latin America and Southeast Asia since a while. 

 

[JBChiangRai]

12 minutes ago, AndreasHG said:

 

Thak you for being honest. I immediately understood you had a vested interest in promoting TCL, but I had no evidence to support my assumption.

 

I have no vested interest. I am not in the AC business, and I am not a shareholder of any of the companies I mentioned above. 

 

My recommendation to the readers herewith is, if they really care about quality, to stay clear of Chinese designed and made units, including TCL.

 

To you my recommendation is to introduce a two-or-three-tiers offering, something the like of good, better, and best. The Thai market is maturing. Customers are getting more experienced, and they start appreciating differences that first time users do not appreciate.

 

If you don't see the need to expand your company offering to include also upmarket solutions now, you may soon. Actually, for your company, it may become a matter of survival, when the market finally really becomes mature. I have seen this trend in Japan first, in Europe thereafter, and in Latin America and Southeast Asia since a while. 

 

 

I think you misunderstood me, we design & build villa housing estates, there is no more "upmarket" developments than ours in Chiang Rai with our houses topping out at 33M.  We have no vested interest in TCL or any other air conditioning manufacturer.

 

I have 6 of TCL 18,000 BTU in my house & another in the garage, 4 of TCL 12,000 BTU units, a 10 year old Mitsubishi 12,000 BTU Heat/Cool and a Fujitsu 36,000 BTU Heat/Cool Cassette unit.  I have another 5 of TCL units in my Chiang Mai house too.

 

I chose TCL for my own house because IMHO they are better than the Japanese/Thai brands, regardless of the fact they are cheaper.  It's cheaper for us to fit a new TCL unit than repair a Daikin, 2 Daikin replaced with TCL in tenants houses in the last 12 months alone.

 

IMHO TCL are the best units you can buy at any price.

[scubascuba3]

10 hours ago, arick said:

It's only 1300 to have an ac fitted. When you purchase the fitting online when buying the air-conditioner. 

Where online is the 1300 fitting?

[MadAtMatrix]

1 hour ago, scubascuba3 said:

Where online is the 1300 fitting?

here is one 1400
https://nocnoc.com/p/Air-Conditioner-Installation/ช่างดี-บริการครบจบเรื่องบ้าน-ค/12096080?area=category-navigationbar-pl&clickType=left click - new tab&entryPoint=Cat PL&pos=7&sourceCarouselPlacement=Category PL

[scubascuba3]

29 minutes ago, MadAtMatrix said:

here is one 1400
https://nocnoc.com/p/Air-Conditioner-Installation/ช่างดี-บริการครบจบเรื่องบ้าน-ค/12096080?area=category-navigationbar-pl&clickType=left click - new tab&entryPoint=Cat PL&pos=7&sourceCarouselPlacement=Category PL

Probably depends on location and if you buy AC through them. I contacted 4 Pattaya companies all quoting roughly the same, not 1400 for sure

[arick]

13 hours ago, scubascuba3 said:

Where online is the 1300 fitting?

When you buy on shopee or Lazada it will give you an option of installing from a separate company they have branches nation wide. Also my local charges 1200 for installation. Maybe I can remind you that minium wage in Thailand is 300 a day. So I don't see why anybody would pay 3000 to install an ac. For two or three hours work   

[arick]

23 hours ago, AndreasHG said:

 

The installation cost is not significantly affected by the size of the unit. It varies based on the complexity of the installation (pipe length, finish, etc.).

 

Regarding the cooling capacity, shops usually do not take any risks and recommend the capacity required in the worst possible scenario (large windows, south facing, exposed to direct sunlight, poor insulation, daytime operation, etc.).

 

f your room does not have such extreme conditions, it is better to choose a unit with a lower capacity.

Oversizing the unit attenuates or negates the benefits of the inverter. Each inverter operates within a certain range around its rated capacity (e.g. 30% to 110%). 
If the nominal capacity of the unit is too high and the typical heat load is close to the minimum capacity of the inverter, the unit does not modulate but operates as an On/Off unit, turning the compressor on and off instead of slowing it down.

 

Don't buy Chinese stuff. Choose renowned brands (Mitsubishi Electric, Daikin, Carrier, Toshiba and Panasonic). 

The best inverter units (those which can provide the highest comfort and energy efficiency) are those with the widest modulation range. Some of these brands' top of the line units are equipped with twin rotary compressors, capable of rotating at a very wide range of RPM, without emitting excessive vibrations.

The advantages offered by a good inverter (wide RPM range) are numerous: the continuous and regular operation of the compressor improves the thermal comfort, the energy efficiency, reduces the mechanical and thermal stress on the AC components boosting its reliability, and reduces the noise.

 

Cheap inverters units (in name only) have narrow modulation ranges (e.g. 70%-100% of the nominal capacity). They are marketed as inverters, but they actually behave most of the time as cheap fix-speed units, continuously switching their compressor On and Off to regulate the temperature.

 

 

My installer use to say dint buy Chinese. Ow he say to buy TCL.

[JBChiangRai]

1 hour ago, arick said:

My installer use to say dint buy Chinese. Ow he say to buy TCL.

 

Our installer said the same 5 years ago when he installed our first TCL units giving me a sideways glance as he did.  

 

Last time I drove past his lock-up, it was stacked to the ceiling with TCL units, he used to push Carrier & Daikin.  He charges us 3,500 baht to install a unit regardless of pipe run, I can get it much cheaper, but I know I can just leave him alone and it will be done properly.  He starts part way through the build and the pipes and drains are in the walls/floors before plastering & tiling.  4 of the units in my own house are on inside walls, you have to do that part way through a build.

 

Unless I want heat capable units, I always go for TCL. TCL in China can heat, but not in Thailand, it's 9 degrees Celsius here this morning, I really wish they could heat...