Fan Power Consumption

[Naam]

What about these ceiling fans? power hungry I would think, anyone know?

not more power hungry than other fans with the same capacity. but slightly less efficient than standing fans because they move warmer air down.

[dddave]

Most of us enjoy a lot of the banter which occurs on here

But Posts and responses like these make TV extra worthwhile

I've often wondered what it costs to use fans......we have them running throughout the day....aircon costs would be a bonus too, if anyone knows.....we seldom use them......my electric bill is 4,700 baht a month as it is

Thanks to everyone who contributed ??

mine is thb 800 and i thought i was paying too much.

great post and great replies, thb 7 a 24 hour day for a massive comfort is really good value.

Have you ever been in rooms so hot that the fans blow hot air and make things worse? That starts happening in the 30's (°C) and particularly with high humidity.

I can't see the point in suffering. Even heavy air con use will only cost a couple of thousand baht extra per month. It's worth it to enjoy a nice cool environment... just cool enough not to sweat with help from well positioned fans. I run mine at 26 - 27°C or 25°C when exercising. I didn't come here to suffer.

When I had my new Samsung converter AC installed last year, both the salesman and installer stressed not setting the thermostat for over 25 degrees. "Over 25 degrees not good for unit" both repeated several times but lacked the language skills to explain why. I wondered if it had to do with reduced capability to deal with high humidity but was never able to find a reliable explanation. Has anybody else been told this? I normally set mine at 26 degrees and move the air with fans. It puts out a lot of water, easily a full standard bucket over 12 hours so de-humidification does not seem an issue.

[Hel123]

How much does it cost per hour to run Air Con units ?

I have 5 units. 9000, 12000, 12000, 18000 and 24000 btu.

Is there a cost per 1000 btu ?

Cheers

H

[dick dasterdly]

What about these ceiling fans? power hungry I would think, anyone know?

not more power hungry than other fans with the same capacity. but slightly less efficient than standing fans because they move warmer air down.

My house gets v hot, so I bought a ceiling fan for the living room. It was only later I thought 'heat rises/ceiling fan will drive heat down' - and so didn't use it for a while.

But then I thought - 'hang on a minute, Hollywood films always show ceiling fans working in films based in India' - so started using it again!

Weirdly, it does seem to drive some of the heat away - and I've no idea why. Are there any physicists amongst us??

[Crossy]

How much does it cost per hour to run Air Con units ?

I have 5 units. 9000, 12000, 12000, 18000 and 24000 btu.

Is there a cost per 1000 btu ?

Cheers

H

Assuming 50% compressor duty cycle and 4.2 Baht per unit for electricity, a very quick and dirty calculation gives approximately :-

9,000 BTU = 3.7 Baht / hr

12,000 BTU = 4.7 Baht / hr

18,000 BTU = 7.4 Baht / hr

24,000 BTU = 9.8 Baht / hr

BUT much depends upon your set temperature and the aspect of the room.

If you like Arctic conditions and with today's temperatures you can double the above numbers

[Hel123]

Also, I don't have a unit inthe utility room and was thinking about one of the portable Air con units - Are they any good ??

[dick dasterdly]

Most of us enjoy a lot of the banter which occurs on here

But Posts and responses like these make TV extra worthwhile

I've often wondered what it costs to use fans......we have them running throughout the day....aircon costs would be a bonus too, if anyone knows.....we seldom use them......my electric bill is 4,700 baht a month as it is

Thanks to everyone who contributed ??

mine is thb 800 and i thought i was paying too much.

great post and great replies, thb 7 a 24 hour day for a massive comfort is really good value.

Have you ever been in rooms so hot that the fans blow hot air and make things worse? That starts happening in the 30's (°C) and particularly with high humidity.

I can't see the point in suffering. Even heavy air con use will only cost a couple of thousand baht extra per month. It's worth it to enjoy a nice cool environment... just cool enough not to sweat with help from well positioned fans. I run mine at 26 - 27°C or 25°C when exercising. I didn't come here to suffer.

When I had my new Samsung converter AC installed last year, both the salesman and installer stressed not setting the thermostat for over 25 degrees. "Over 25 degrees not good for unit" both repeated several times but lacked the language skills to explain why. I wondered if it had to do with reduced capability to deal with high humidity but was never able to find a reliable explanation. Has anybody else been told this? I normally set mine at 26 degrees and move the air with fans. It puts out a lot of water, easily a full standard bucket over 12 hours so de-humidification does not seem an issue.

Are there any physicists on this forum?

Surely it can't be true that an aircon needs to be set lower than 25C???

[CGW]

^ This article makes sense regarding settings https://thenakedlistener.wordpress.com/2011/09/15/acmyths2/

[Hel123]

Hi Crossy,

Thanks for the info - I'm setting the Aircon at 22c but because the rooms in my house have floor to ceiling windows and they get the sun in the afternoon the room temp is normally about 26c and I struggle to get it lower in the afternoon.....

My gut feel is that the builders underspec'd the Air Con to keep their costs down - I've added the 24000 & 9000 since I moved into the house - All the units are LG and seem ok but are noisier than the Daikin I had in my condo - I know Daikin are more expensive so I can live with the noise Lol !

[dick dasterdly]

Also, I don't have a unit inthe utility room and was thinking about one of the portable Air con units - Are they any good ??

No. They take up a lot of room and look ugly. To make it worse, they cost the same (or at least close) to an aircon to run.

I bought one and a few months later threw it away...

[tropo]

How much does it cost per hour to run Air Con units ?

I have 5 units. 9000, 12000, 12000, 18000 and 24000 btu.

Is there a cost per 1000 btu ?

Cheers

H

Assuming 50% compressor duty cycle and 4.2 Baht per unit for electricity, a very quick and dirty calculation gives approximately :-

9,000 BTU = 3.7 Baht / hr

12,000 BTU = 4.7 Baht / hr

18,000 BTU = 7.4 Baht / hr

24,000 BTU = 9.8 Baht / hr

BUT much depends upon your set temperature and the aspect of the room.

If you like Arctic conditions and with today's temperatures you can double the above numbers

I'm trying to determine the BTU of my air conditioning units. Does the yellow "Ministry of Energy" sticker (written in Thai) give that information. If not, where can I find it?

[tropo]

Hi Crossy,

Thanks for the info - I'm setting the Aircon at 22c but because the rooms in my house have floor to ceiling windows and they get the sun in the afternoon the room temp is normally about 26c and I struggle to get it lower in the afternoon.....

My gut feel is that the builders underspec'd the Air Con to keep their costs down - I've added the 24000 & 9000 since I moved into the house - All the units are LG and seem ok but are noisier than the Daikin I had in my condo - I know Daikin are more expensive so I can live with the noise Lol !

If your units can't get the temperature down to your set temp, the compressors will stay on. If you can only achieve 26, you're better off setting it at 26 to give them a break. I had this problem with a unit and my electric bills were ridiculous.

[dick dasterdly]

^ This article makes sense regarding settings https://thenakedlistener.wordpress.com/2011/09/15/acmyths2/

The linked article would be more believable if it wasn't written by someone living in a relatively cold country. He actually says 'FACT, the actual optimal thermostat setting is 20-23C'...! Ridiculous for those of us living in Thailand.

But perhaps I'm wrong, and if we set our aircon at 22C it will save us lots of money...

Edit - Sorry, I've just realised we're going way off topic talking about aircon when the subject is fans.

In short the - fans are cheap to run.

[dick dasterdly]

Hi Crossy,

Thanks for the info - I'm setting the Aircon at 22c but because the rooms in my house have floor to ceiling windows and they get the sun in the afternoon the room temp is normally about 26c and I struggle to get it lower in the afternoon.....

My gut feel is that the builders underspec'd the Air Con to keep their costs down - I've added the 24000 & 9000 since I moved into the house - All the units are LG and seem ok but are noisier than the Daikin I had in my condo - I know Daikin are more expensive so I can live with the noise Lol !

If your units can't get the temperature down to your set temp, the compressors will stay on. If you can only achieve 26, you're better off setting it at 26 to give them a break. I had this problem with a unit and my electric bills were ridiculous.

Thanks for this as I recently bought an aircon for downstairs - and it takes literally hours to get down to the set 30C...

Even though its less than a month old (and I gave HomePro the square metres to be covered), presumably it needs to be replaced for a more powerful unit. Somehow I know that HomePro will be less than interested in my 'not up to the job' argument as I have no proof that I told them the square metreage.

As always, I learn by my mistakes .

[Naam]

Are there any physicists on this forum?

Surely it can't be true that an aircon needs to be set lower than 25C???

of course it's not true, most of his comments are rubbish²

setting all our aircons to 22ºC would mean during the hot season a monthly electricty bill of ~85,000 Baht because they'd run 24/7 in cooling mode.

someome who doesn't know that a/c (airconditioning) means in many countries cooling and heating is an uneducated bigmouth.

signed:

physicist (retired)

[tropo]

^ This article makes sense regarding settings https://thenakedlistener.wordpress.com/2011/09/15/acmyths2/

The linked article would be more believable if it wasn't written by someone living in a relatively cold country. He actually says 'FACT, the actual optimal thermostat setting is 20-23C'...! Ridiculous for those of us living in Thailand.

But perhaps I'm wrong, and if we set our aircon at 22C it will save us lots of money...

Edit - Sorry, I've just realised we're going way off topic talking about aircon when the subject is fans.

In short the - fans are cheap to run.

I've also read that the optimum room temperature for health is 21°C. I suppose the people who write this crap think everyone lives in a cool climate.

IMO 26°C is a perfect indoor temperature here in Thailand provided you have some fans. The more fans the higher you can set it. At night time, after a few hours I put mine up to 27°C as the body cools down during sleep. This can vary though, because when the humidity is really high the air conditioners won't drop it (humidity) as low.

People back at home look puzzled when I say I drop my room temperature DOWN to 27°C when I sleep. That sounds really weird to people living in countries where 27°C night time temperatures are unheard of, or if achieved would be the hottest nights of the whole year.

[dddave]

I figure it costs on average about B100/day to air condition my 60 s/m studio using an 18,000 Samsung inverter unit. There is one lengthwise, south facing wall that can get warm to the touch. Some months are 200-300 over B3000, some 200-300 less. I run it about 16 to 20 hours most days.

Seems to me a reasonable price to pay for the comfort it provides.

Curious to the opinion of others. If I'm going out and know I will return in under 2 hours, I usually leave my AC on, 27 degrees, low fan. I figure the cost of re-cooling the room would equal or surpass the cost of leaving it on.

Agree or disagree?

[dick dasterdly]

^ This article makes sense regarding settings https://thenakedlistener.wordpress.com/2011/09/15/acmyths2/

The linked article would be more believable if it wasn't written by someone living in a relatively cold country. He actually says 'FACT, the actual optimal thermostat setting is 20-23C'...! Ridiculous for those of us living in Thailand.

But perhaps I'm wrong, and if we set our aircon at 22C it will save us lots of money...

Edit - Sorry, I've just realised we're going way off topic talking about aircon when the subject is fans.

In short the - fans are cheap to run.

I've also read that the optimum room temperature for health is 21°C. I suppose the people who write this crap think everyone lives in a cool climate.

IMO 26°C is a perfect indoor temperature here in Thailand provided you have some fans. The more fans the higher you can set it. At night time, after a few hours I put mine up to 27°C as the body cools down during sleep. This can vary though, because when the humidity is really high the air conditioners won't drop it (humidity) as low.

People back at home look puzzled when I say I drop my room temperature DOWN to 27°C when I sleep. That sounds really weird to people living in countries where 27°C night time temperatures are unheard of, or if achieved would be the hottest nights of the whole year.

Thanks Tropo and Naam - I was beginning to wonder whether I was missing something obvious to everyone else!

Using more fans to supplement aircon sounds like a good idea and definitely worth a try.

Had to laugh at your comment about people looking puzzled when you talk about dropping the night time room temp to 27C, as I can remember back in the UK we all complained and couldn't sleep when the (night) temp was 20C !

[tropo]

Had to laugh at your comment about people looking puzzled when you talk about dropping the night time room temp to 27C, as I can remember back in the UK we all complained and couldn't sleep when the (night) temp was 20C !

In actual fact people look more than puzzled when they hear that - they think I'm crazy.

They don't understand that you can't drop temperatures too low when the outside temperatures are usually over 30°C all year.

[fforest1]

After running through these fan and air-con numbers it suddenly dawned on me

(yea I am slow) that it cost roughly the

same to run a 18 inch fan for 24 hrs as it does to run a 12,000 btu air-con at full power for 1 hour..

I know this is not a exact comparison because it depends on the air-con size and cold setting and the fan speed and this comparison can easily be off by a few baht..

But roughly its not to far off..

[Naam]

After running through these fan and air-con numbers it suddenly dawned on me

(yea I am slow) that it cost roughly the

same to run a 18 inch fan for 24 hrs as it does to run a 12,000 btu air-con at full power for 1 hour..

I know this is not a exact comparison because it depends on the air-con size and cold setting and the fan speed and this comparison can easily be off by a few baht..

But roughly its not to far off..

you are indeed not far off and your calculation inspired me to do a similar comparison but i need some assistance with one of the factors.

here we go:

1 kilo of good but not top quality Beluga caviar sells for approximately 9,000 US-Dollars. how much is 1 kilo of dried squid?

[fforest1]

Naam that is a good question which only proves my point..

After running through these fan and air-con numbers it suddenly dawned on me

(yea I am slow) that it cost roughly the

same to run a 18 inch fan for 24 hrs as it does to run a 12,000 btu air-con at full power for 1 hour..

I know this is not a exact comparison because it depends on the air-con size and cold setting and the fan speed and this comparison can easily be off by a few baht..

But roughly its not to far off..

[buddy]

This question does come up occasionally, I never record the results so have to do the test every time, it only takes a few minutes (usually takes longer to find the power meter)

I edited my post slightly after following your link, my fan is pretty close to the one you linked to.

What brand and type of power meter do you use?

[Crossy]

This question does come up occasionally, I never record the results so have to do the test every time, it only takes a few minutes (usually takes longer to find the power meter)

I edited my post slightly after following your link, my fan is pretty close to the one you linked to.

What brand and type of power meter do you use?

It's a Prodigit 2000MU power consumption meter.

http://www.prodigit.com/product_c_3.php?button_num=g10&this_cname=&folder_id=31&cnt_id=15&orderby=2

Came off Ebay, about 12 Quid IIRC.

[Naam]

Naam that is a good question which only proves my point..

After running through these fan and air-con numbers it suddenly dawned on me

(yea I am slow) that it cost roughly the

same to run a 18 inch fan for 24 hrs as it does to run a 12,000 btu air-con at full power for 1 hour..

I know this is not a exact comparison because it depends on the air-con size and cold setting and the fan speed and this comparison can easily be off by a few baht..

But roughly its not to far off..

there's one thing to consider. the diameter of a fan is irrelevant as far as consumption is concerned. one of my attic exhausts fans (12" squirrel cage) draws

550 watts.

my whole house fan, diameter 40" draws ~370 Watts.

[buddy]

This question does come up occasionally, I never record the results so have to do the test every time, it only takes a few minutes (usually takes longer to find the power meter)

I edited my post slightly after following your link, my fan is pretty close to the one you linked to.

What brand and type of power meter do you use?

It's a Prodigit 2000MU power consumption meter.

http://www.prodigit.com/product_c_3.php?button_num=g10&this_cname=&folder_id=31&cnt_id=15&orderby=2

Came off Ebay, about 12 Quid IIRC.

Wow i am surprised it is so cheap...what brand and type do you use to measure 3 phase power consumption?

[Naam]

This question does come up occasionally, I never record the results so have to do the test every time, it only takes a few minutes (usually takes longer to find the power meter)

I edited my post slightly after following your link, my fan is pretty close to the one you linked to.

What brand and type of power meter do you use?

It's a Prodigit 2000MU power consumption meter.

http://www.prodigit.com/product_c_3.php?button_num=g10&this_cname=&folder_id=31&cnt_id=15&orderby=2

Came off Ebay, about 12 Quid IIRC.

Wow i am surprised it is so cheap...what brand and type do you use to measure 3 phase power consumption?

just by measuring "N" with a clamp-meter and converting amps in watts?

where are you Crossy?

[tropo]

After running through these fan and air-con numbers it suddenly dawned on me

(yea I am slow) that it cost roughly the

same to run a 18 inch fan for 24 hrs as it does to run a 12,000 btu air-con at full power for 1 hour..

I know this is not a exact comparison because it depends on the air-con size and cold setting and the fan speed and this comparison can easily be off by a few baht..

But roughly its not to far off..

you are indeed not far off and your calculation inspired me to do a similar comparison but i need some assistance with one of the factors.

here we go:

1 kilo of good but not top quality Beluga caviar sells for approximately 9,000 US-Dollars. how much is 1 kilo of dried squid?

LOL. I can help you with the dried squid query. Premium dried squid at Foodland goes for 735 baht per kilo. It's my wife's favourite.