Cost to run 12,200 BTU air con for 18hrs a day?

[mug3k]

Hi Guys,

 

I've just moved into a condo in Chiang Mai for 6 months and I'd like to get an idea up front of how much it'll cost to run the air con unit for around 18 hours a day. The condo has 2 air con units but I'll only ever be using one at a time. The actual apartment is quite small at 30sqm with the living room being about 18 and the bedroom around 12. The electric rate is 4 baht which I understand is the government rate. The whole building is very new and probably roughly 2 years old and apparently I'm the first person to move into this room.

 

I've attached an image of the spec sheet for the model of air con unit (Mitsubishi SRK/C13CRV-S1) as maybe one of you guys will be able to make sense of it, I'm not very technically inclined. If you need any more information from me let me know.

 

I hope I've put this post in the right section 

 

Thanks,

Edited January 27, 2017 by mug3k
model number

[trogers]

Cost = 1 Kwh x 18hrs x Bt4

[Crossy]

So from the table it's about 1kW when the compressor is running.

 

Assuming it's roughly the right size (not seriously under sized) then a duty ration of 3:1 is reasonable.

 

So it will use about 1kWhr (unit) every 3 hours. So in 18 hours that's 6 units = 24 Baht.

 

If you are correct and both units are 12,000 BTU they are maybe 50% too big for the space to be cooled, the consumption will be lower, but you won't get the drying effect so the air may feel clammy.

[trogers]

38 minutes ago, Crossy said:

So from the table it's about 1kW when the compressor is running.

 

Assuming it's roughly the right size (not seriously under sized) then a duty ration of 3:1 is reasonable.

 

So it will use about 1kWhr (unit) every 3 hours. So in 18 hours that's 6 units = 24 Baht.

 

If you are correct and both units are 12,000 BTU they are maybe 50% too big for the space to be cooled, the consumption will be lower, but you won't get the drying effect so the air may feel clammy.

Duty ration of 3:1 would only be applicable to the smaller air-con set to 24C for the night in the bedroom.

 

The larger unit operating during the day for the living room would probably sees 1:3...

[mug3k]

2 hours ago, Crossy said:

So from the table it's about 1kW when the compressor is running.

 

Assuming it's roughly the right size (not seriously under sized) then a duty ration of 3:1 is reasonable.

 

So it will use about 1kWhr (unit) every 3 hours. So in 18 hours that's 6 units = 24 Baht.

 

If you are correct and both units are 12,000 BTU they are maybe 50% too big for the space to be cooled, the consumption will be lower, but you won't get the drying effect so the air may feel clammy.

If it's really only going to be around 24 baht for 18 hours I may as well run it for the whole 24 hours. I thought it was going to be a lot more than this so it's a welcome surprise.

 

1 hour ago, trogers said:

Duty ration of 3:1 would only be applicable to the smaller air-con set to 24C for the night in the bedroom.

 

The larger unit operating during the day for the living room would probably sees 1:3...

What does this mean, will it be much more expensive to run than what Crossy said?

[trogers]

14 minutes ago, mug3k said:

If it's really only going to be around 24 baht for 18 hours I may as well run it for the whole 24 hours. I thought it was going to be a lot more than this so it's a welcome surprise.

 

What does this mean, will it be much more expensive to run than what Crossy said?

How often the compressor of the air-con unit kicks in would depend on the difference between the temperature (and humidity) of the air outside, and the temperature set in your remote control.

 

The larger the difference, the more  duration the compressor has to work. And that difference would be the greatest in the early afternoon.

[KhunBENQ]

9 hours ago, mug3k said:

The electric rate is 4 baht which I understand is the government rate.

For a condo this is a bargain!

Government rates (PEA) are from a gliding price scale which currently might result in a 4 Baht average price.

There are so many factors that influence the actual duty ratio like the location/number and size of windows. Overall insulation quality/materials.

And as written of course big variation depending on exterior temperature.

Currently temperatures in Chiang Mai are quite mild and cool in the night.

You really expect to run an AC for 18h currently?

Temperatures are comparable to our region.

Our ACs are off since months.

Another two months and the tide will turn.

 

 

 

[mug3k]

44 minutes ago, trogers said:

How often the compressor of the air-con unit kicks in would depend on the difference between the temperature (and humidity) of the air outside, and the temperature set in your remote control.

 

The larger the difference, the more  duration the compressor has to work. And that difference would be the greatest in the early afternoon.

I see, I guess I'll just have to wait and see what the first bill is like. Hopefully I'll become more acclimated to the heat and won't feel it as much after a while. It's first week here so and coming from winter in the UK is a stark contrast.

 

30 minutes ago, KhunBENQ said:

For a condo this is a bargain!

Government rates (PEA) are from a gliding price scale which currently might result in a 4 Baht average price.

There are so many factors that influence the actual duty ratio like the location/number and size of windows. Overall insulation quality/materials.

And as written of course big variation depending on exterior temperature.

Currently temperatures in Chiang Mai are quite mild and cool in the night.

You really expect to run an AC for 18h currently?

Temperatures are comparable to our region.

Our ACs are off since months.

Another two months and the tide will turn.

 

 

 

 I probably don't use it 18 hours at the moment but I can see it being that much or more when it starts heating up over the next few months. On both the living room and the bedroom, windows cover 1 side.

 

I'm hoping to keep the water and electricity bills under 3000 baht.

[KhunBENQ]

8 minutes ago, mug3k said:

I'm hoping to keep the water and electricity bills under 3000 baht.

Average over the year this sounds feasible (assuming the 4 Baht per unit).

Expect more in April/May.

 

We have two comparable units.

During the real bad months they run all night and one unit also a couple of hours during the day.

About 3100 is the highest single bill for electricity we had last year (incl. a water pump and the "usual stuff"). Water bill is peanuts here.

[mug3k]

27 minutes ago, KhunBENQ said:

Average over the year this sounds feasible (assuming the 4 Baht per unit).

Expect more in April/May.

 

We have two comparable units.

During the real bad months they run all night and one unit also a couple of hours during the day.

About 3100 is the highest single bill for electricity we had last year (incl. a water pump and the "usual stuff"). Water bill is peanuts here.

That sounds OK then, the 2 you run at night and the one you run for a few hours in day must come close to 20 hours which is probably the most I'd both units combined (never on at the same time).

 

I'm not so worried about a crazy bill now 

[lkn]

5 minutes ago, mug3k said:

I'm not so worried about a crazy bill now 

My bill has gone down with ~2,000 baht since I stopped using A/C in October/November.

 

And I pay 3.25 baht/unit (excl. VAT which is 7%).

 

I suggest you keep an eye on your meter to find out how much you’re actually using. Once it gets warmer, your A/C will consume a lot more power. 

[trogers]

1 hour ago, mug3k said:

I see, I guess I'll just have to wait and see what the first bill is like. Hopefully I'll become more acclimated to the heat and won't feel it as much after a while. It's first week here so and coming from winter in the UK is a stark contrast.

 

 I probably don't use it 18 hours at the moment but I can see it being that much or more when it starts heating up over the next few months. On both the living room and the bedroom, windows cover 1 side.

 

I'm hoping to keep the water and electricity bills under 3000 baht.

You can set the air-con in the living room to 26C and augment the cooling with a stand fan, rather than to 24-25C.

[wpcoe]

6 hours ago, Crossy said:

 

If you are correct and both units are 12,000 BTU they are maybe 50% too big for the space to be cooled, the consumption will be lower, but you won't get the drying effect so the air may feel clammy.

 

This is a significant factor.  A 12,000 BTU unit for a 18 sq.m room might be okay, but a 12,000 BTU unit for a 12 sq.m room is waaay oversized, and since it's in a bedroom and will probably be running at night, there will be very little dehumidifying going on.

 

A general rule for air con capacity here in Thailand is to multiply sq.m by 600.  So for the 18 sq.m room that would be about 11,000 BTU, but for the 12 sq.m room it's only 7,200 BTU.  Mainly daytime factors, like lots of single-pane glass facing west or uninsulated ceiling on the top floor can increase the heat load, but at night a 12,000 BTU unit for a 12 sq.m room is not ideal.

 

Now, if these were *inverters*, that would be mitigated a little bit, but for a standard unit, not so much.

 

In one apartment I rented where the bedroom air con was similarly oversized, I would run only one air con and then place a floor fan to blow the cool air into the other room.  That way it reasonably dehumidified because the compressor engaged for longer periods since it was cooling both rooms.

[mug3k]

16 minutes ago, wpcoe said:

This is a significant factor.  A 12,000 BTU unit for a 18 sq.m room might be okay, but a 12,000 BTU unit for a 12 sq.m room is waaay oversized, and since it's in a bedroom and will probably be running at night, there will be very little dehumidifying going on.

 

A general rule for air con capacity here in Thailand is to multiply sq.m by 600.  So for the 18 sq.m room that would be about 11,000 BTU, but for the 12 sq.m room it's only 7,200 BTU.  Mainly daytime factors, like lots of single-pane glass facing west or uninsulated ceiling on the top floor can increase the heat load, but at night a 12,000 BTU unit for a 12 sq.m room is not ideal.

 

Now, if these were *inverters*, that would be mitigated a little bit, but for a standard unit, not so much.

 

In one apartment I rented where the bedroom air con was similarly oversized, I would run only one air con and then place a floor fan to blow the cool air into the other room.  That way it reasonably dehumidified because the compressor engaged for longer periods since it was cooling both rooms.

I'm sorry I made a mistake, the one in the bedroom is the smaller unit in the chart on my first post, it is 9,200 BTU so it's still oversized but not so bad.

[mug3k]

1 hour ago, trogers said:

You can set the air-con in the living room to 26C and augment the cooling with a stand fan, rather than to 24-25C.

Can 1 degree make a big difference in running costs?

[wpcoe]

26 minutes ago, mug3k said:

I'm sorry I made a mistake, the one in the bedroom is the smaller unit in the chart on my first post, it is 9,200 BTU so it's still oversized but not so bad.

 Now, we're making progress!  

[trogers]

3 hours ago, mug3k said:

Can 1 degree make a big difference in running costs?

A saving of Bt10 to Bt12 a day would add up in a month and help to pay for the electricity consumption of your refrigerator...

[Pigdog747]

14 hours ago, mug3k said:

Can 1 degree make a big difference in running costs?

 everything makes a difference, I stopped worrying about it, kept the temp at 25  and found that my Hydro bill is about 1200 Bt during the cooler months and 3500 Bt for the hot months give or take a couple of 100 Bt.

 

[juehoe]

In my office in Hua Hin, I use a 19,000 BTU inverter aircon (from Samsung). The aircon runs 9 hours a day. The temperature is set at 24 °C. We use additional ceiling fans.

The electricity bill is about THB 2,000 per month (500 kWh at 4 THB/kWh).

[little mary sunshine]

OMG....so much about nothing....Turn on the AC, be comfortable 

and pay the bill when it arrives.  

[masuk]

20 hours ago, KhunBENQ said:

For a condo this is a bargain!

Government rates (PEA) are from a gliding price scale which currently might result in a 4 Baht average price.

There are so many factors that influence the actual duty ratio like the location/number and size of windows. Overall insulation quality/materials.

And as written of course big variation depending on exterior temperature.

Currently temperatures in Chiang Mai are quite mild and cool in the night.

You really expect to run an AC for 18h currently?

Temperatures are comparable to our region.

Our ACs are off since months.

Another two months and the tide will turn.

 

 

 

I'm in Chiang Mai, and ran my air con for a few hours each evening for about 10 weeks last year;  This lowered the humidity, and closing doors and windows before switching on, kept it down most of the night.

 

Mornings are cooler anyway.

 

While Thais are still to discover the benefit of window awnings  and roof insulation, this is the tropics.

 

 

[Ulic]

My electric bill for a 37sm apartment is about 1,400 baht in the summer and 900 in the winter.

I run one of two aircons about 18 hrs a day and pay the PEA government rate directly at the 7-11.

 I also cook on electric.

[seancbk]

My electric bill was for 356 kWh last month, that included running the AC at night but not much during the day.  

Cost was 1350 billed direct from the Metropolitan Electricity Authority.     During the summer my bill peaks at around 2200 THB.

That is 3.79 baht per kWh.

[Bung]

Simply try it for a month and see what your bill is.  If your bill is too high turn it down or off.  If you can afford more run it longer.  No need for complicated maths. 

[aussiandrew]

Its simple if you use an A/C most of the day 7 days a week budget in the hot season ball park costs 4,000 BH and the cooler months live now 1200BH. Good luck with your budgeting.

[Autonuaq]

Add some isolation to your walls and sealing as well put some oslolating folm in your windows.

Change the entree door to make a lock between cokd and warm

 

Saves a lot.

 

Bill droped from 3500 thb to 2200 thb and charged on a glijding price.

 

Then exchanged the lamps to led and also the tv and bill dropped more to 1900 thb

 

Had to reolace my refrigde and bougt one with inverter. Saves also.

 

And because of the gloding scale we dropped a little more

[themerg]

2500 Baht a month in Chiang Mai. Use many fans and open windows instead.

[themerg]

Question :  What are you doing inside for 18 hours a day, when there is a very Beautiful Thailand outside ?

[shaurene]

First you need to convert the BTU (British therm units) to KW. 

12200 BTU approx 3.5 KW

if your elec power cost your 5 baht a unit ( a unit of power. Is 1,000 watts. 1 KW.)

So, you are useing 3.5 units of power each hour. Let's go 18 Baht per hour.

So 18 hours per day @ 18 BT = 324  BT per day. I think I have this right.

also take into account setting your temp on the remote around 26c so the compressor will be turning off when your area is 26c and coming back on above this temp. I would work out 280 BT average per day.

keep your eye on the filters clean them regular. Just lift the cover up on the unit on the wall you will see if the filters are dirty, pull them out and wash them. If they are dirty it will use more power.

hope this helps.

 

 

 

[paulsingle]

To those who say just use it when you want to and pay the bill, I say some of use are interested to see how the cost may be reduced. Some of us need to budget. Money saved on electricity can be spent on other pleasures.

Apart from budgeting it's good environmental practice to reduce consumption where possible. 

Here in Phuket we only use aircon in the bedroom. 25°C for about 12 hours.

Our average electicity bill for the past 3 months is 1,500 baht.

We use overhead fans in the living room.