Time to replace my Aircons ? Efficiency

[BangkokBoyJohnny]

My house's 5 ACs are York by Johnston Controls and they've been super reliable for the past 12 or so years.

 

I've researched old vs new and it would appear the new units to mine are possibly 33% to 50% more efficient, maybe...

Has anyone changed to new ACs and noticed and dramatic reduction on Electricity usage, if so how much?

 

I'm sure you would, I'm just trying to work out my ROI as such...

 

Many thanks

BBJ...

 

PS ACs used in 3 bedrooms overnight, and afternoons on weekends occasionally...

 

 

 

[KannikaP]

Let's say your old 1200BTU unit takes about 1000 watts per hour, and the new one 500, you are saving half a unit per hour per a/c.= Bht 2.5 (in simple numbers). On for 8 hours a day = Bht 25 = Bht 600 per 30-day month.

Cost of new Inverter a/c unit is around the Bht 20,000 mark. 20,000/600 = 333 months.

Change these figure to suit your situation.

[tgw]

10 minutes ago, KannikaP said:

Let's say your old 1200BTU unit takes about 1000 watts per hour, and the new one 500, you are saving half a unit per hour per a/c.= Bht 2.5 (in simple numbers). On for 8 hours a day = Bht 25 = Bht 600 per 30-day month.

Cost of new Inverter a/c unit is around the Bht 20,000 mark. 20,000/600 = 333 months.

Change these figure to suit your situation.

maths require exact numbers to work - 12000BTU , 33.3 months.

 

I feel the price of aircons has also gone down. I recently replaced an aircon for just 8.000 THB, and have been saving 600-800 THB per month, so I guess it will have paid for itself within a year.

 

[KhunLA]

Comparing old house/AC draw (non inverter), and new house/AC draw (heavy duty inverter), then yes, major difference and immediately noticed.

 

Both house builds identical, AAC block, insulated roof/ceiling, and well shaded with roof extension.

 

Mitsubishi fan, as they've never failed me in 20+ yrs.

[KannikaP]

12 minutes ago, tgw said:

maths require exact numbers to work - 12000BTU , 33.3 months.

 

I feel the price of aircons has also gone down. I recently replaced an aircon for just 8.000 THB, and have been saving 600-800 THB per month, so I guess it will have paid for itself within a year.

 

OOps sorry, one zero too many. 

[Yellowtail]

If your 15-year-old conventional units were sized correctly and well maintained, replacing with new inverter units will likely save 10-20% in electric. 

 

Replacing them with new conventional units might save 5%

 

I replaced three >20-year-old York units with new inverters in the last few years and I'm saving maybe 1,500 a month. 

 

I still have two old Yorks, an old Mitsubishi and an old Carrier left to replace, but they are only used occasionally. 

 

 

[KhunBENQ]

1 hour ago, tgw said:

maths require exact numbers to work

And 25 times 30 is 750 not 600

Gives roughly 27 months. A bit more than two years.

If assumptions are realistic(?) then worth any time.

Particularly as the units are 12 years old.

 

Realistic? Maybe a bit too optimistic?

[KhunBENQ]

1 hour ago, BangkokBoyJohnny said:

PS ACs used in 3 bedrooms overnight, and afternoons on weekends occasionally...

Would you tell what your typical electricity consumption is?

Units per month?

[Kwasaki]

Costs savings depend on the insulation efficiency of the house build.

I found no difference in savings electric use from buying a cold blow air-con unit or a air-con inverter unit only that the inverters are more expensive and we're difficult to find anyone to fix em.

 

 

[Yellowtail]

When replacing a conventional unit with an inverter unit: 

 

If the old unit was oversized (likely), you should see significant savings. 

If the old unit was sized correctly (unlikely), you will see some savings. 

If the old unit was undersized you should see no savings, and it may cost more. 

 

 

[BangkokBoyJohnny]

9 hours ago, KhunLA said:

Comparing old house/AC draw (non inverter), and new house/AC draw (heavy duty inverter), then yes, major difference and immediately noticed.

 

Both house builds identical, AAC block, insulated roof/ceiling, and well shaded with roof extension.

 

Mitsubishi fan, as they've never failed me in 20+ yrs.

Thanks KhunLA, can you tell us how much you're saving in THB and % pls ? ...Just roughly ...Thanks

[BangkokBoyJohnny]

9 hours ago, Yellowtail said:

If your 15-year-old conventional units were sized correctly and well maintained, replacing with new inverter units will likely save 10-20% in electric. 

 

Replacing them with new conventional units might save 5%

 

I replaced three >20-year-old York units with new inverters in the last few years and I'm saving maybe 1,500 a month. 

 

I still have two old Yorks, an old Mitsubishi and an old Carrier left to replace, but they are only used occasionally. 

 

 

Thanks YellowTail so maybe 500thb pcm per AC saving ie 5k thb pa...

Maybe 5-10 years to get ROI then...

[BangkokBoyJohnny]

8 hours ago, KhunBENQ said:

Would you tell what your typical electricity consumption is?

Units per month?

Hi KhunBENQ

 

8k to 10k pcm, 4 bed villa,

 

ACs on in 3 rooms at night,

swimming pool,

Washing machine 1-2 times per day,

20 garden lights on for security at night,

3 fridges...

 

[BangkokBoyJohnny]

1 hour ago, Yellowtail said:

When replacing a conventional unit with an inverter unit: 

 

If the old unit was oversized (likely), you should see significant savings. 

If the old unit was sized correctly (unlikely), you will see some savings. 

If the old unit was undersized you should see no savings, and it may cost more. 

 

 

I would estimate sized correctly to oversized !!!!

[BangkokBoyJohnny]

8 hours ago, Kwasaki said:

Costs savings depend on the insulation efficiency of the house build.

I found no difference in savings electric use from buying a cold blow air-con unit or a air-con inverter unit only that the inverters are more expensive and we're difficult to find anyone to fix em.

 

 

Mine's like a typical 4 bed Supalai Villa so no known insulation to speak of and was built 12-13 years old.

I wonder if "they" build more energy efficient homes nowadays?

[KannikaP]

10 hours ago, KannikaP said:

Let's say your old 1200BTU unit takes about 1000 watts per hour, and the new one 500, you are saving half a unit per hour per a/c.= Bht 2.5 (in simple numbers). On for 8 hours a day = Bht 25 = Bht 600 per 30-day month.

Cost of new Inverter a/c unit is around the Bht 20,000 mark. 20,000/600 = 333 months.

Change these figure to suit your situation.

Sorry, 20,000/600 is 33.3 months.

[Kwasaki]

1 hour ago, BangkokBoyJohnny said:

Mine's like a typical 4 bed Supalai Villa so no known insulation to speak of and was built 12-13 years old.

I wonder if "they" build more energy efficient homes nowadays?

well as I said an inverter will not save you much..