Air conditioning - Any recommendations please?? - Part 2

GBC

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Hi all!

Just came back from Gain City and the uncle kept recommending Mitsubishi Heavy Industries System 3 (3 x 12000 BTU), so I got it. Now I'm wondering if I made the wrong decision, for based on what I read online, people usually get 2 X 9000 BTU and 1 X 12000BTU (master bedroom)? Would 3 x 12000 BTU consume more electricity?

My flat:

Master bedroom: About 18sqm
Bedrooms 1 & 2: About 14sqm

Could anyone please advice? Thanks!
Can your outdoor compressor support 36,000 BTU ?
 

Alphas

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Hi all!

Just came back from Gain City and the uncle kept recommending Mitsubishi Heavy Industries System 3 (3 x 12000 BTU), so I got it. Now I'm wondering if I made the wrong decision, for based on what I read online, people usually get 2 X 9000 BTU and 1 X 12000BTU (master bedroom)? Would 3 x 12000 BTU consume more electricity?

My flat:

Master bedroom: About 18sqm
Bedrooms 1 & 2: About 14sqm

Could anyone please advice? Thanks!
Higher commission for MHI. 9K BTU is sufficient for 14 sqm bedroom.
 

XDeathLoRdz

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Hi all!

Just came back from Gain City and the uncle kept recommending Mitsubishi Heavy Industries System 3 (3 x 12000 BTU), so I got it. Now I'm wondering if I made the wrong decision, for based on what I read online, people usually get 2 X 9000 BTU and 1 X 12000BTU (master bedroom)? Would 3 x 12000 BTU consume more electricity?

My flat:

Master bedroom: About 18sqm
Bedrooms 1 & 2: About 14sqm

Could anyone please advice? Thanks!
My family went gaincity last week and the sales person also pushy for this setup, so my family got it.
Awaiting for installation...

I initially want 9000btu for all 3 room now i got 12000, i was also wondering if it will consume more electricity
 

GBC

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My family went gaincity last week and the sales person also pushy for this setup, so my family got it.
Awaiting for installation...

I initially want 9000btu for all 3 room now i got 12000, i was also wondering if it will consume more electricity
It's like asking whether a bigger car use more petrol..
 

Sparcs

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My family went gaincity last week and the sales person also pushy for this setup, so my family got it.
Awaiting for installation...

I initially want 9000btu for all 3 room now i got 12000, i was also wondering if it will consume more electricity

Below are what I have learned from far, and happy to be corrected by the more experienced folks here.

Noticed that for Gaincity, they tend to quote the higher BTU FCUs because the price differential between the different FCU sizes are quite marginal. From my own research so far (based on ME and Toshiba), it ranges between $40 - $50 per size upgrade per unit. ie. 12k BTU is approx $50 more than a 9k BTU. Whether this is right approach to just whack the largest FCU, I am not sure as there are different perspective.

I think reference back to the manufacturer's specs can determine what is the actual BTU output when units are simultaneously turned on, and if that is sufficient based on your expected typical usage. Using the SCM80YT-S compressor as example here, below is what is given in the brochure.

Rated cooling capacity if all 3 units are turned on:
3 x 9k units: 2.5kW = ~8,500 BTU
2 x 9k units + 1 x 12k unit: 9k unit = 9k @ 2.35kW (~8k BTU), 12k @ 3.29kW (~11.2k BTU)
3 x 12k units: 2.67kW = ~9,100 BTU

For electrical consumption difference, you can calculate based on the manufacturer's specs again. Following from the example above, rated input energy as below:

- 3 x 9k = 1,580 W
- 2 x 9k + 1 x 12k = 1,650 W
- 3 x 12k = 1,650 W

Based on above, clearly there is more electricity usage. If assume all 3 units are turned on 24hrs a day, an estimate of extra cost, assuming $0.30/kWh, on a yearly basis = (1650 - 1580)/1000 x 24 x 365 x 0.3 = ~$184
 

XDeathLoRdz

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Below are what I have learned from far, and happy to be corrected by the more experienced folks here.

Noticed that for Gaincity, they tend to quote the higher BTU FCUs because the price differential between the different FCU sizes are quite marginal. From my own research so far (based on ME and Toshiba), it ranges between $40 - $50 per size upgrade per unit. ie. 12k BTU is approx $50 more than a 9k BTU. Whether this is right approach to just whack the largest FCU, I am not sure as there are different perspective.

I think reference back to the manufacturer's specs can determine what is the actual BTU output when units are simultaneously turned on, and if that is sufficient based on your expected typical usage. Using the SCM80YT-S compressor as example here, below is what is given in the brochure.

Rated cooling capacity if all 3 units are turned on:
3 x 9k units: 2.5kW = ~8,500 BTU
2 x 9k units + 1 x 12k unit: 9k unit = 9k @ 2.35kW (~8k BTU), 12k @ 3.29kW (~11.2k BTU)
3 x 12k units: 2.67kW = ~9,100 BTU

For electrical consumption difference, you can calculate based on the manufacturer's specs again. Following from the example above, rated input energy as below:

- 3 x 9k = 1,580 W
- 2 x 9k + 1 x 12k = 1,650 W
- 3 x 12k = 1,650 W

Based on above, clearly there is more electricity usage. If assume all 3 units are turned on 24hrs a day, an estimate of extra cost, assuming $0.30/kWh, on a yearly basis = (1650 - 1580)/1000 x 24 x 365 x 0.3 = ~$184
Thanks Sparcs, this is a very helpful insights.
 

petetherock

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Below are what I have learned from far, and happy to be corrected by the more experienced folks here.

Noticed that for Gaincity, they tend to quote the higher BTU FCUs because the price differential between the different FCU sizes are quite marginal. From my own research so far (based on ME and Toshiba), it ranges between $40 - $50 per size upgrade per unit. ie. 12k BTU is approx $50 more than a 9k BTU. Whether this is right approach to just whack the largest FCU, I am not sure as there are different perspective.

I think reference back to the manufacturer's specs can determine what is the actual BTU output when units are simultaneously turned on, and if that is sufficient based on your expected typical usage. Using the SCM80YT-S compressor as example here, below is what is given in the brochure.

Rated cooling capacity if all 3 units are turned on:
3 x 9k units: 2.5kW = ~8,500 BTU
2 x 9k units + 1 x 12k unit: 9k unit = 9k @ 2.35kW (~8k BTU), 12k @ 3.29kW (~11.2k BTU)
3 x 12k units: 2.67kW = ~9,100 BTU

For electrical consumption difference, you can calculate based on the manufacturer's specs again. Following from the example above, rated input energy as below:

- 3 x 9k = 1,580 W
- 2 x 9k + 1 x 12k = 1,650 W
- 3 x 12k = 1,650 W

Based on above, clearly there is more electricity usage. If assume all 3 units are turned on 24hrs a day, an estimate of extra cost, assuming $0.30/kWh, on a yearly basis = (1650 - 1580)/1000 x 24 x 365 x 0.3 = ~$184
Thanks, it's very useful indeed.
Bear in mind a few things:
- these calculations work well for HDB units. You may need a larger compressor for condos, which tend to have higher ceilings
- a bigger BTU unit is also needed if you have more people at home, eg if you entertain often. You won't want to wait half an hour for the room to cool and strain your compressor
- there are more units with lofts these days and again, the numbers will be different
- finally a larger compressor will work less hard than one which is undersized
- the difference in consumption is also less as we don't use it 24/7... most folks use it for a few hours at night
- lastly, if one lives near the top or faces a western direction, you may need a larger unit to cool down the home..
 

tc12345

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Getting a 7 year resale condo and have kinda decided to change the air-con. Any reliable shop recommendation to assess whether should I change the piping as well?
 

petetherock

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Typically if it's under 10 yrs, it should be ok. But any good aircon contractor should be able to do it if he is worth his salt. If he can't, you best avoid using him for the new aircons.
 

nncnfrmst

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Planning to replace all aircons + compressors for my HDB flat reno and just found out that the aircon contractor used by my ID will not send any BCA-trained installers for the job. So we have decided not to use their contractor and to find our own. (Same for the electrical works, unfortunately.) Just posting here to warn others to check (if you are renovating a HDB flat).
 

lwt11137

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Power consumption very much affected by if the FCU is not clean periodically and Chemical cleaning not done when necessary. Additional heat source in the cooling area example direct sunlight, massage chair, hotpot and Audio equipment etc....
 

Bankthekid

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Thinking of getting a 3+1 system for my resale house. Just wondering what the BTU should be for my living room?



My contracted insisted I should get 24k but I think this is a bit… overkill?

I could opt for 18k / 20k and there’ll be q a substantial savings…

What do you guys think?
 

Asus80

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my Aircon Mitsubishi Heavy Industries System 3 using 4 year old. power trip i suspect is compressor problems & i call KM capital Group. compressor is 5 year warranty parts only but charge me labour $500+ to $700+ bfe GST so endup i install new MITSUBISHI ELECTRIC STARMEX sys 3 coming this thursday $2700 using back my old pipe
 

Shutterfly

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Is it advisable to use back existing pipes (around 18 years old)? And change later if any issues..
 
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