Aircon using too much electric?

[cyril sneer]

Last month I moved to a different apartment and was shocked to get my electric bill yesterday, so have today been testing the meter readings: -

 

12 hours using fan, lighting, hot shower, tv used 1.1 units

1 hour with aircon turned on (28 degrees) used 1.4 units

 

The room (24 square metres) just uses one small air conditioner. Surely this is too high? (About 10 baht an hour)

 

I've stayed in many other rooms of similar size all charging the same 8 baht a unit, but this electric bill was quadruple what i'm used to paying..

[Sheryl]

Is it a very old machine? They do start to use more juice when they get old.

 

Also check that the filter is clean (if not, clean it) and have a look at the inside slats etc, a lot of Thai landlords (and renters) are very remiss  when it comes to having units cleaned. You can get professional cleaning for about 600 baht and, if the machine was dirty, this can improve performance a lot.

[Pattaya46]

8 minutes ago, cyril sneer said:

1 hour with aircon turned on (28 degrees) used 1.4 units

Hi. This aircon has a serious problem. It needs at least a good revision. 

(Looks like it struggles to make cold and then turns full throttle all time ?)

 

I use 2-3 units per day to keep my condo at 28°C...

[CharlieH]

Moved to Electrical forum.

[scorecard]

21 minutes ago, Sheryl said:

Is it a very old machine? They do start to use more juice when they get old.

 

Also check that the filter is clean (if not, clean it) and have a look at the inside slats etc, a lot of Thai landlords (and renters) are very remiss  when it comes to having units cleaned. You can get professional cleaning for about 600 baht and, if the machine was dirty, this can improve performance a lot.

and If it's an LG machine (and maybe others) check the buttons on the remote control.

 

Remote for LG has a button on the right hand side, 3 up from the bottom, says "Saver', or 'Saving'.

 

After starting machine, now press saver / saving, and you'll be shocked at the reduction in the fai far bill.

 

 

[Lacessit]

Check how long ago the refrigerant was replenished. Thai maintenance can be fairly haphazard. There are calculations online for how many BTU's are needed for 24 sqm. Possibly the unit is undersized.

[cyril sneer]

The date says 2007 so old yes, it’s a Fujitsu

[wayned]

Sounds about right to me for an "old" non-inverter unit.  If the room is 24 square meters the correct size unit would be 14000 BTU ( 24 x 6000 btu/ square meter = 14,400 BTU).  An old 14000 BTU unit would use about 1400 watts per hour,which equates to 1,4 units on the meter.  Best bet ias to get the unoit professionally cleaned.

[meatpie]

Old, ive got an Amercan Made one 27 yers old run every day thats outlived 5 Thai brands.Serviced by hours run , superb machine.


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[wayned]

1 hour ago, wayned said:

Sounds about right to me for an "old" non-inverter unit.  If the room is 24 square meters the correct size unit would be 14000 BTU ( 24 x 6000 btu/ square meter = 14,400 BTU).  An old 14000 BTU unit would use about 1400 watts per hour,which equates to 1,4 units on the meter.  Best bet ias to get the unit professionally cleaned.

correction' 24 x 600 (Not 6000) = 14400

[faraday]

4 hours ago, meatpie said:

Old, ive got an Amercan Made one 27 yers old run every day thats outlived 5 Thai brands.Serviced by hours run , superb machine.


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Yes of course you have, & it's American. What more could anyone want.

 

????

[Crossy]

Assuming it's a 14,000 BTU unit (you need to locate the model number so we can check).

 

At about 30% duty cycle (which you should get or exceed) that's 1,400 Watt/Hours x 30% = 420 Watt hours or about 0.4 units. Running flat-out it's going to be around 1.4 units.

 

Have you cleaned the filters in the indoor unit?

 

Is the air coming from the indoor unit cold? Does the compressor cycle (start/stop) whilst it's running?

 

Like others have noted, I suspect it's in trouble and needs a service / re-gas. Time to call the man.

 

[faraday]

Does the outside extractor fan ever need servicing?

 

Coz the fan's in the house (not a/c) get filthed up, & I clean them.

 

I would have thought that the external fans need cleaning also....?

[cyril sneer]

3 hours ago, Crossy said:

Assuming it's a 14,000 BTU unit (you need to locate the model number so we can check).

 

At about 30% duty cycle (which you should get or exceed) that's 1,400 Watt/Hours x 30% = 420 Watt hours or about 0.4 units. Running flat-out it's going to be around 1.4 units.

 

Have you cleaned the filters in the indoor unit?

 

Is the air coming from the indoor unit cold? Does the compressor cycle (start/stop) whilst it's running?

 

Like others have noted, I suspect it's in trouble and needs a service / re-gas. Time to call the man.

 

i googled the model number which comes up with this, my unit has the exact same sticker

 

 

the filters look clean already, cold air does come out, and the compressor does cycle on and off

 

I did another test through the night when the temperature was down and the room already at 28 degrees and it only used 0.5 units an hour

 

so your calculations of 1.4 and 0.4 seem close to how much it should be using anyway

 

i'm intrigued to know why my previous bills were so much cheaper, do newer aircon units save much more in comparison?

 

 

[Crossy]

OK, so that unit will be using a maximum of 1.1 units per hour, at 30% that's more like 0.4 units per hour.

 

[moe666]

12 hours ago, Pattaya46 said:

Hi. This aircon has a serious problem. It needs at least a good revision. 

(Looks like it struggles to make cold and then turns full throttle all time ?)

 

I use 2-3 units per day to keep my condo at 28°C...

More than likely it needs a good cleaning including the condenser. The evaporator fins are probably coated with dirt as well as the fan blades. get it cleaned and see hoew it works

[luckyluke]

Call for Naam. 

[lopburi3]

31 minutes ago, cyril sneer said:

i'm intrigued to know why my previous bills were so much cheaper, do newer aircon units save much more in comparison?

Yes new units are much more efficient - your unit is marked EER 3.45.  My new Daikin 8500 btu inverter (cooling 26sm fine to same 27-28 range) has SEER of 26 (about 15 EER).

[cyril sneer]

14 minutes ago, lopburi3 said:

Yes new units are much more efficient - your unit is marked EER 3.45.  My new Daikin 8500 btu inverter (cooling 26sm fine to same 27-28 range) has SEER of 26 (about 15 EER).

how many units does that use an hour?

[Pilotman]

13 hours ago, Pattaya46 said:

Hi. This aircon has a serious problem. It needs at least a good revision. 

(Looks like it struggles to make cold and then turns full throttle all time ?)

 

I use 2-3 units per day to keep my condo at 28°C...

you may as well be outside. 

[lopburi3]

Your unit is marked 1100w so max usage should be 1.1 units per hour if on full time.

 

Inverter is on full time but running DC motor at much lower wattage than full almost all the time so can not directly compare other than with the eer/seer ratings.  Max usage is 680 watts.

Correction to previous post - my model is the less expensive Daikin with SEER of 20 which is about 14.4 EER.

[meatpie]

Maintenance is the where the Ferang can go Native, at best messing about himself , anything to avoid the 400/ 500 per unit. I mentioned America Made because even the Old service chaps admit the Thai made Carrier is just a re badge Thai . Dont dismiss your unit for age, or expect the amazing savings of Inverters claimed by every ferang who has one. i run 5 and they I saves a bit, but nothing like you notice.


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[lopburi3]

4 minutes ago, Pilotman said:

you may as well be outside. 

Unless physically working 27-28 is fine for most people once they get used to a hot climate.  This is especially true with inverters that blow the cooler air full time.  It is 35 or more outside this time of the year. 

Edited April 2, 2019 by lopburi3

[Pilotman]

Just now, lopburi3 said:

Unless physically working 27-28 is fine for most people once they get used to a hot climate.  

with no aircon or fans running, unless the day is particularly hot, the temp in my house, rarely exceeds 28, 29 degrees. It is out in the country with normally a slight flow of air through the house.  

[DualSportBiker]

1 hour ago, cyril sneer said:

i googled the model number which comes up with this, my unit has the exact same sticker

 

 

the filters look clean already, cold air does come out, and the compressor does cycle on and off

 

I did another test through the night when the temperature was down and the room already at 28 degrees and it only used 0.5 units an hour

 

so your calculations of 1.4 and 0.4 seem close to how much it should be using anyway

 

i'm intrigued to know why my previous bills were so much cheaper, do newer aircon units save much more in comparison?

 

 

I sell energy efficiency technology for AC to schools and hotels. From anecdotal data from my customers, you could expect to save up to 40% if you replace a 10-year old AC.

 

3.8 kW cooling capacity is 13,000 BTU. Most AC engineers I talk here to use between 600 and 900 BTU per sqm depending on insulation, exposure to sun and walk-in heat (school have hot kids walking into rooms...) Your AC is slightly underpowered which means the duty cycle will be higher and therefore more costly. Having extra cooling capacity costs less to run.

[wayned]

1 hour ago, cyril sneer said:

i'm intrigued to know why my previous bills were so much cheaper, do newer aircon units save much more in comparison?

Smaller inverter type unit!

[DualSportBiker]

24 minutes ago, wayned said:

Smaller inverter type unit!

Unlikely. If comparing unit to unit... he could easily have had a smaller AC before...

 

FYI

95% of an AC's cost is running the compressor. A small unit needs to use the compressor more than a larger one. Even though its rated consumption is lower, it will consume more power in total.

 

Inverters only save if they have spare cooling capacity. Their motors are variable-speed where at 80% output, they consume just 50% of rated power consumption. However, they can also run at 120% output which consumes over 150% of rated consumption. Put into too large a room and an inverter will cost more to run.

 

A school 200 km outside of Bangkok I tried to sell to bought 500 inverters of the same rated BTU as those they replaced. They regretted that decision; savings only came at the cost of comfort. Rooms were hot unless they set to lower temperature than before, but then the savings all but disappeared.

 

If you want to upgrade to an inverter, buy a larger capacity unit than that which you are replacing. 10 to 20% should prevent disappointment.

Edited April 2, 2019 by DualSportBiker
clarity

[meatpie]

At last someone talking sense.I ve used Central Air , no upsell no bull and fast service response.!.I chose inverters they said same as above post. Our inverter fridge freez iv never noticed except it runs cooler on the outside.



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[Dazinoz]

6 hours ago, faraday said:

Does the outside extractor fan ever need servicing?

 

Coz the fan's in the house (not a/c) get filthed up, & I clean them.

 

I would have thought that the external fans need cleaning also....?

People often only clean the indoor unit filter. Often the fins which do the cooling need cleaning too. The fins in the outdoor unit need cleaning too as they transfer the heat away. I had mine cleaned with a high pressure cleaner last year here in Chiang Mai and I was surprised how dirty they were. Unit operated much better after. My friend lives in an apartment block where they had people come clean every AC unit. Just after cleaning I arrived and noted the outdoor unit still looked dirty and asked my friend. She said she didn't know. Just then a lady from the cleaning team walked past so my friend asked her about cleaning the outdoor unit. She spoke in Thai to my friend and indicated a circular motion then walked off. I asked my friend what did she say and she said outdoor unit does not need cleaning as nothing in it except fan. Much more fin area in the outdoor unit exposed to more dirt especially this time of year. So much for a professional cleaning crew.

[Thainesss]

I dont understand how you guys have your aircons set at 28 - 29 degrees. Thats still hot as balls for an indoor living space.