Aircon Old Vs New, Cheap Vs Expensive

[h90]

I have an Panasonic 9000 BTU Aircon and just my feeling tells me (I know you can be very wrong on that) that it is nearly as strong as the cheap noname Aircon with 18.000 BTU.

What I see as main difference is that the capilar valve (if it is called like that, I mean the very small tubes for reducing the pressure), are at the panasonic not visible (inside) while on the cheap one the installation guys solder it outside.

As well it is always impossible to force them to use the tube which is written on the housing, they just use what they have.

the thais told me that old aircons use a lot more electricity than new one. I have there also no explanation beside that with every time they install it somewhere different they add some new mistakes.

Has anyone knowlege on that? At the moment I go ahead and put insulation instead of exchanging the airconditions, as this can never be wrong (the Thais call me already Farang bah as they see insulation as complete waste of money)....

[Dragonman]

Insulation is always a good idea if installed correctly for a tropical climate!

9,000 btu should be for a room of about 45 square metres. It does not mean that you will see much increase in strength from a 18,000 btu if installed in a room which does not have the defined space, as it will close down more often.

Check to see what the Energy Efficiency Ratio (EER) of your current model is. It should be 10.7-10.8. Mine is 10.73. If you have a 9.8 you will only save about 100 baht a month by changing it. Unless you have to, or care for the environment, hardly a reason.

[PeaceBlondie]

Speaking of EER's and efficiency, all the large Thai electrical appliances seem to use the half-circle device from one to five, and they all rate a 5 out of 5. Meaning, the only way you can tell how much electricity it uses, is to read the fine print below that, which seems to be an estimate of electricity cost per year to operate it.

EER is a rating used in the West, but is it displayed on Thai air conditioners? Isn't the formula for EER derived by dividing the BTU's per watts?

[Dragonman]

Speaking of EER's and efficiency, all the large Thai electrical appliances seem to use the half-circle device from one to five, and they all rate a 5 out of 5. Meaning, the only way you can tell how much electricity it uses, is to read the fine print below that, which seems to be an estimate of electricity cost per year to operate it.

EER is a rating used in the West, but is it displayed on Thai air conditioners? Isn't the formula for EER derived by dividing the BTU's per watts?

It is on my Samsung. 1st line down on the sticker after the name. But not on my Fiji (in book)

Yes divide btu by watts required to provide cooling.

[h90]

Insulation is always a good idea if installed correctly for a tropical climate!

9,000 btu should be for a room of about 45 square metres. It does not mean that you will see much increase in strength from a 18,000 btu if installed in a room which does not have the defined space, as it will close down more often.

Check to see what the Energy Efficiency Ratio (EER) of your current model is. It should be 10.7-10.8. Mine is 10.73. If you have a 9.8 you will only save about 100 baht a month by changing it. Unless you have to, or care for the environment, hardly a reason.

My EER on the newer one is 3.35-3.19, that might be something different.

The 3 other aircons don't have anything like that.

But beside that, has the installation an influence, as I see that pressure valve and have my doubts that it is the original one.

As well I have doubts if they know exactly how to fill it. A little bit more or less gas would make a difference?

I see the two cold tubes go together in one insulating tube, does that make sense? The gas comming back should be already warmer and heats the coming cold one?

Inside where it sucks the gas the tube and where it enters the compressor is very cold and a lot wather is condensing, isn't that a loose? Or is that such a small amount that it does not need attention?

We have no 4 Aircons and I am afraid about the bills (we are new in the house). An average of 2 Aircons 24 hours a day 7 days a week are running

day: 2 office rooms+1 production room=3

night: sleeping room

they all run full speed as the can not reach the temp. we set (26 degree).

[jing jing]

9,000 btu should be for a room of about 45 square metres.

Is that right? How about for a bedroom size 4 x 4 meters?

[Gary A]

A 9,000 BTU split unit was the smallest I could find. My bedroom is about 4 X 4 meters and it cools it quite well. I bought a Samsung because it was the most efficient unit I could find. The remote control stinks but other than that air conditioner works well. I did lower the bedroom ceiling but the windows are typical Thai and jing joks manage to get in and out. Screens are a necessity and the curtains also help.

Note - The air con runs all night when it is hot and my electric bill is normally less than a thousand baht per month.

9,000 btu should be for a room of about 45 square metres.

Is that right? How about for a bedroom size 4 x 4 meters?

Edited June 28, 2006 by Gary A

[jing jing]

I'm just wondering if 9000 BTU is really adequate for 45 sq. met., and if so, how can the same unit be appropriate for a 16 sq. met. room? I've got a 4 x 6 meter living room adjoining a 3 x 6 meter kitchen/dining area with no door between them - that's 42 sq. met. combined, and I was told that even a 24K BTU unit was too small for that area.

[PeaceBlondie]

Some of the factors to be considered in calculating required BTU include:

square meters of floor space

height of ceiling

amount of windows, and their exposure to direct sunlight

insulation of all surfaces, including glass thickness

location - we're all in the tropics, but Chiang Rai is not Yala

location - shade or direct exposure

location - is there a large mass of uncooled space above, below, or next door?

[h90]

I'm just wondering if 9000 BTU is really adequate for 45 sq. met., and if so, how can the same unit be appropriate for a 16 sq. met. room? I've got a 4 x 6 meter living room adjoining a 3 x 6 meter kitchen/dining area with no door between them - that's 42 sq. met. combined, and I was told that even a 24K BTU unit was too small for that area.

I have 9000 BTU for 32 sqm, Panasonic. It now with half of the ceiling is insulated it works well, but it would not be a mistake if would be a bit stronger.

With the full ceiling insulated it will do the job easily I think.

I had before a 18K BTU NoName in a 16 sqm room with poor insulation and it could not do it.

I think also the 18K BTU where more a wishfull thinking of the factory than really a fact.

As Blondie writes, there are a lot of other factors.

As I had before over my room approx. 50 degree and just maybe 1 cm plasterboard, than a lot of heat comes in. If that is insulated and for example the room below you is also cool you may save 50 % of the power....

[Gary A]

A quick simple answer is NO! If I open the bedroom door and use a fan to push out the cool air into my living/dining room area It will take the edge off but to call it cool would be stretching the facts. That total area is about 34 square meters.

I'm just wondering if 9000 BTU is really adequate for 45 sq. met., and if so, how can the same unit be appropriate for a 16 sq. met. room? I've got a 4 x 6 meter living room adjoining a 3 x 6 meter kitchen/dining area with no door between them - that's 42 sq. met. combined, and I was told that even a 24K BTU unit was too small for that area.

[Dragonman]

I'm just wondering if 9000 BTU is really adequate for 45 sq. met., and if so, how can the same unit be appropriate for a 16 sq. met. room? I've got a 4 x 6 meter living room adjoining a 3 x 6 meter kitchen/dining area with no door between them - that's 42 sq. met. combined, and I was told that even a 24K BTU unit was too small for that area.

I have 9000 BTU for 32 sqm, Panasonic. It now with half of the ceiling is insulated it works well, but it would not be a mistake if would be a bit stronger.

With the full ceiling insulated it will do the job easily I think.

I had before a 18K BTU NoName in a 16 sqm room with poor insulation and it could not do it.

I think also the 18K BTU where more a wishfull thinking of the factory than really a fact.

As Blondie writes, there are a lot of other factors.

As I had before over my room approx. 50 degree and just maybe 1 cm plasterboard, than a lot of heat comes in. If that is insulated and for example the room below you is also cool you may save 50 % of the power....

Yes there are many other factors and the square metres figure should only be really be used as a guideline. 18,000 btu however will never be efficient in 16 sqm! Even in a tropical climate and with no insulation, and with sun on the room 8,000-9,000 if serviced regularly should be adequate.

jing jing. The no door, plus a kitchen raises the requirements to around 18,000btu. Personally in my previous property I installed 2 x 9,000btu.

Although I managed to find 8,300btu's for my 5x4 rooms. 9,000 seems to be the norm. in Thailand. Reason being they are much more easily installed than smaller units, and most companies include installation.

[elkangorito]

Some of the factors to be considered in calculating required BTU include:

square meters of floor space

height of ceiling

amount of windows, and their exposure to direct sunlight

insulation of all surfaces, including glass thickness

location - we're all in the tropics, but Chiang Rai is not Yala

location - shade or direct exposure

location - is there a large mass of uncooled space above, below, or next door?

Further to PeaceBlondie's comments, the amount of people who will normally inhabit the space is also important. Each human generally generates about 700 to 900 BTU. Anyway, BTU's are old units which are no longer used...Kilowatts please.

A 9 000 BTU unit should be able to adequately cool a volume of approx. 100 to 125 cubic metres. "Adequately" means that the compressor is not running all the time & is therefore cycling on & off (at an assumed temperature of between 22 to 25 degrees Celsius). Modern air cond. units are VSD controlled (Variable Speed Drive) as well as microprocessor controlled, which makes them more efficient. Do not confuse efficiency with the ability to cool larger volumes.

I will ask one of my air cond. contractors if they have an "assessment" sheet. If I can get one, I will post it here.

[h90]

Some of the factors to be considered in calculating required BTU include:

square meters of floor space

height of ceiling

amount of windows, and their exposure to direct sunlight

insulation of all surfaces, including glass thickness

location - we're all in the tropics, but Chiang Rai is not Yala

location - shade or direct exposure

location - is there a large mass of uncooled space above, below, or next door?

Further to PeaceBlondie's comments, the amount of people who will normally inhabit the space is also important. Each human generally generates about 700 to 900 BTU. Anyway, BTU's are old units which are no longer used...Kilowatts please.

A 9 000 BTU unit should be able to adequately cool a volume of approx. 100 to 125 cubic metres. "Adequately" means that the compressor is not running all the time & is therefore cycling on & off (at an assumed temperature of between 22 to 25 degrees Celsius). Modern air cond. units are VSD controlled (Variable Speed Drive) as well as microprocessor controlled, which makes them more efficient. Do not confuse efficiency with the ability to cool larger volumes.

I will ask one of my air cond. contractors if they have an "assessment" sheet. If I can get one, I will post it here.

don't kill me if my answer is a bit inocent....

per human arround 150-200 Watt can that be right?

If yes that lighting/Computer does also count.

in my understanding the cubic meter do not count, the square meter to the outside do (makes a big differents how your room is shaped) and how the insulation is (of course).

VSD, what is VSD? The compressor? Even my modern expensive one has just switch the compressor on/off and I guess the compressor is just an asynchronus motor, or is there anything newer? If the compressor can change its volume/min than also the valve must adjust itself, or? Than it is not the capillar pressure reduction tube anymore. Than you can not fill the device with just watching the two (or just one) pressure on the gauge (which all do).

I don't doubt what you are writing (my old Saab has something like that) but are you sure that already arrived in Thailand?

[Dragonman]

[

Anyway, BTU's are old units which are no longer used...Kilowatts please.

Yeah, yeah, Aussies and Yanks (tons) never like us Poms to have any International recognition!

[elkangorito]

Some of the factors to be considered in calculating required BTU include:

square meters of floor space

height of ceiling

amount of windows, and their exposure to direct sunlight

insulation of all surfaces, including glass thickness

location - we're all in the tropics, but Chiang Rai is not Yala

location - shade or direct exposure

location - is there a large mass of uncooled space above, below, or next door?

Further to PeaceBlondie's comments, the amount of people who will normally inhabit the space is also important. Each human generally generates about 700 to 900 BTU. Anyway, BTU's are old units which are no longer used...Kilowatts please.

A 9 000 BTU unit should be able to adequately cool a volume of approx. 100 to 125 cubic metres. "Adequately" means that the compressor is not running all the time & is therefore cycling on & off (at an assumed temperature of between 22 to 25 degrees Celsius). Modern air cond. units are VSD controlled (Variable Speed Drive) as well as microprocessor controlled, which makes them more efficient. Do not confuse efficiency with the ability to cool larger volumes.

I will ask one of my air cond. contractors if they have an "assessment" sheet. If I can get one, I will post it here.

don't kill me if my answer is a bit inocent....

per human arround 150-200 Watt can that be right?

If yes that lighting/Computer does also count.

in my understanding the cubic meter do not count, the square meter to the outside do (makes a big differents how your room is shaped) and how the insulation is (of course).

VSD, what is VSD? The compressor? Even my modern expensive one has just switch the compressor on/off and I guess the compressor is just an asynchronus motor, or is there anything newer? If the compressor can change its volume/min than also the valve must adjust itself, or? Than it is not the capillar pressure reduction tube anymore. Than you can not fill the device with just watching the two (or just one) pressure on the gauge (which all do).

I don't doubt what you are writing (my old Saab has something like that) but are you sure that already arrived in Thailand?

Most TX valves are self adjusting, according to pressure. A lot of late model air cond. units use EX valves. Some (but not all) late model air cond. units, control the compressor & condensor fan by VSD (Variable Speed Drive), which is more efficient but requires lots of technology. An example of this technology would be in Sharp (brand name) air conds.

[h90]

Some of the factors to be considered in calculating required BTU include:

square meters of floor space

height of ceiling

amount of windows, and their exposure to direct sunlight

insulation of all surfaces, including glass thickness

location - we're all in the tropics, but Chiang Rai is not Yala

location - shade or direct exposure

location - is there a large mass of uncooled space above, below, or next door?

Further to PeaceBlondie's comments, the amount of people who will normally inhabit the space is also important. Each human generally generates about 700 to 900 BTU. Anyway, BTU's are old units which are no longer used...Kilowatts please.

A 9 000 BTU unit should be able to adequately cool a volume of approx. 100 to 125 cubic metres. "Adequately" means that the compressor is not running all the time & is therefore cycling on & off (at an assumed temperature of between 22 to 25 degrees Celsius). Modern air cond. units are VSD controlled (Variable Speed Drive) as well as microprocessor controlled, which makes them more efficient. Do not confuse efficiency with the ability to cool larger volumes.

I will ask one of my air cond. contractors if they have an "assessment" sheet. If I can get one, I will post it here.

don't kill me if my answer is a bit inocent....

per human arround 150-200 Watt can that be right?

If yes that lighting/Computer does also count.

in my understanding the cubic meter do not count, the square meter to the outside do (makes a big differents how your room is shaped) and how the insulation is (of course).

VSD, what is VSD? The compressor? Even my modern expensive one has just switch the compressor on/off and I guess the compressor is just an asynchronus motor, or is there anything newer? If the compressor can change its volume/min than also the valve must adjust itself, or? Than it is not the capillar pressure reduction tube anymore. Than you can not fill the device with just watching the two (or just one) pressure on the gauge (which all do).

I don't doubt what you are writing (my old Saab has something like that) but are you sure that already arrived in Thailand?

Most TX valves are self adjusting, according to pressure. A lot of late model air cond. units use EX valves. Some (but not all) late model air cond. units, control the compressor & condensor fan by VSD (Variable Speed Drive), which is more efficient but requires lots of technology. An example of this technology would be in Sharp (brand name) air conds.

I worry for problems, if that unit gets a problem and khun somchai, former rice farmer, now self assigned aircon specialist tries to fix the problem. Else it sounds great, specially adjustable valves must bring a lot efficiency...

[bkkexplorer]

I have an old, no name air conditioner that is labeled 18-20000 BTU cooling a 40sm2 room (7 foot insulated ceilings in an apartment). After reading this thread, would it be safe to say I'll be OK with a new A/C using half the BTU?

Would that reduce the electric bills by half?

tks.

[elkangorito]

I have an old, no name air conditioner that is labeled 18-20000 BTU cooling a 40sm2 room (7 foot insulated ceilings in an apartment). After reading this thread, would it be safe to say I'll be OK with a new A/C using half the BTU?

Would that reduce the electric bills by half?

tks.

In short, no.

On the other hand, reducing the capacity of the a/c unit may increase your electricity bills.

Cooling capacity is cooling capacity...it's just that the modern units use less electricity to perform the task.

BTW, 20 000 BTU sounds about right for 40 square metres. Most people in Thailand (and Australia) who do not bother to have a "professional" survey done, tend to "guess" the size of unit. This normally results in a unit that is too small to do the job & consequently, the compressor runs almost constantly.

Remember, 25 degrees Celsius is an economical temperature. Always measure this temp at about head height (most people do not spend all day standing in rooms...they tend to sit).

[jing jing]

BTW, 20 000 BTU sounds about right for 40 square metres. Most people in Thailand (and Australia) who do not bother to have a "professional" survey done, tend to "guess" the size of unit. This normally results in a unit that is too small to do the job & consequently, the compressor runs almost constantly.

OK, but earlier in this thread someone said:

"9,000 btu should be for a room of about 45 square metres."

Seems like there is some contradictory information here. I understand that there are many variables in determining exactly what cooling capacity is needed, but assmuming some sort of average ceiling height and temperature, does anyone know a rule of thumb for calculating BTU per square meter?

[Dragonman]

BTW, 20 000 BTU sounds about right for 40 square metres. Most people in Thailand (and Australia) who do not bother to have a "professional" survey done, tend to "guess" the size of unit. This normally results in a unit that is too small to do the job & consequently, the compressor runs almost constantly.

OK, but earlier in this thread someone said:

"9,000 btu should be for a room of about 45 square metres."

Seems like there is some contradictory information here. I understand that there are many variables in determining exactly what cooling capacity is needed, but assmuming some sort of average ceiling height and temperature, does anyone know a rule of thumb for calculating BTU per square meter?

My Air Con Unit for my living room is 12,000btu for 55 sqm. I waited to see what the engineer suggested, although I knew the size I wanted. It is totally adequate, cools total area in around 15 minutes. Personally I would find 20,000 btu far too much. If you want to see some ways to do rough calculations google "air conditioners btu". My experience is that people have units far too big in Thailand!

[jing jing]

My experience is that people have units far too big in Thailand!

Heheheh... passing up the double entendre opportunity, I'll just point out that someone stated the exact opposite a few posts up. A friend of mine who's done some research agrees with you, however, it seems surprisingly difficult to find a consensus on this subject.

[MartinBKK]

I have recently been in the market for a new air con and i went to at least 5 different shops.

The advice i got was that for a room of 20sqm 13000 BTU is needed. This advice was given by 4/5 shops with the other saying that 16000 BTU was necessary.

I bought a Daikin 13000 BTU and it cools the room just fine.

[bkkexplorer]

Thanks for all the posts and teaching me a thing or two about aircons...

The compressor on my A/C does frequently go off at night. I guess the 20000 BTU cooling capacity is more than enough for a 45 sm2 room. I understand the logic that if you use a lower BTU, the compressor will have to work harder to keep the room temperature down. So, in that sense it might not neccesary mean lower bills. I think this would be a fair statement if they were aircons of simmilar models/ timeframes.

Again, mine is at least ten years old. The monthly electric bills come is at least 3000 baht/month. I only switch on the A/C at night til morning. Just trying to figure out, if I did get a new one at half the BTU, maybe in the long run (a year or so) the 'potentially' lower bills would make up for buying a new one. Make any sense??

[Swelters]

These comments, partly posted on another discussion, are more appropriate here:

-Agree with the 9000 Btu recommendation. Too bad there aren't smaller units (say 5000 Btu) as in the US, they would allow great energy savings in Thailand.

-seal the room to prevent unnecessary moisture infiltration. Most of the energy is spent condensing water not cooling air, which is what you want anyway, ie air at 40 percent rel hum instead of 70 percent so you can effectively use your own evaporative cooling system (perspiration). (That's the nice feeling you get when you enter an airconditioned room.) Cold air, ie 25 C or lower, isn't really all that great. Get used to say 28 C and 50 percent RH.

-shade walls and roofs exposed to sun, especially concrete which will bleed heat well into the evening, you will be solar heating walls and roof uselessly, then paying to cool them at night. Insulation is a second choice. Your body may produce only 100 watts, but your warm ceiling will yield 10 times as much.

-dont oversize the aircon unit and then run it on "energy saving mode." It will cycle on and off and do a bad job of dehumidfying and deliver air that is too cold for comfort. 9000 btu/hr units should be fine for small rooms. A "heat pipe" addon to you aircon which precools and reheats conditioned air may be beneficial.

Swelters

[elkangorito]

I'm not an Air Conditioning Engineer but I am an Electrical Engineer & I am also a Facilities Manager in Australia (very hot). In my 20 years or so experience, 20 000 BTU is about the correct size for 40 to 50 square metres (given the insulation & glass heat gains). If others suggest that their smaller a/c units are performing adequately, then the only question that remains is "how efficient is their a/c unit?" Does the compressor 'cycle' or does it run continuously for long periods?

Tomorrow, I will ask one of my Refrigeration Mechanics to supply me with an "air conditioning survey" guide. I think you will all be surprised as to what size a/c will perform "efficiently".

Edited July 6, 2006 by elkangorito

[Gary A]

Can anyone tell me what the 9284 BTU/h 2700W means. The 2700W confuses me. Down below it says 3.7 A 800W.

[elkangorito]

Can anyone tell me what the 9284 BTU/h 2700W means. The 2700W confuses me. Down below it says 3.7 A 800W.

Nearly all air conditioning units will have two "kilowatt" ratings listed.

One of these ratings is associated with electrical energy consumption whilst the other is asociated with cooling capacity.

As a general rule, multiply Watts (cooling capacity) by 3.4 to give BTU/h.

The unit you mention is obviously a single phase unit (220 volts), thus 3.7 Amps multiplied by 220 volts equals 814 Watts (approx 800).

For cooling capacity conversion, multiply 2700 Watts by 3.4 & you get about 9180 BTU/h.