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Air conditioning - Any recommendations please??

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Old 04-05-2016, 10:27 AM   #7306
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For those interested in MHI, check out today's Straits Times, Home section, B3.

MHI offer free upgrades for blowers from 9k to 12k.
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Old 04-05-2016, 10:32 AM   #7307
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For those interested in MHI, check out today's Straits Times, Home section, B3.

MHI offer free upgrades for blowers from 9k to 12k.
any scanned or photo of that one ?
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Old 04-05-2016, 10:54 AM   #7308
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Old 04-05-2016, 11:46 AM   #7309
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what do you all think of the promo?
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Old 04-05-2016, 12:21 PM   #7310
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I think 9k blower and 12k price diff is $100+
If you dont need a bigger cooling capacity no point getting a 12k fcu
I rather they offer extra warranty period. Aircon repair is really very expensive after warranty. The transport, labour, inspection fee alone can burn the pocket.
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Old 04-05-2016, 12:34 PM   #7311
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what do you all think of the promo?
Depends on how powerful the outdoor unit is. Most system 3 is around 22 to 28k btu i belive? I'd rather have 3 ◊ 9000btu running efficiently rather than 2 units 12000 and the last one at 4000 or something struggling to cool the room. Of course depends on a a few factors, do you use all 3 units at night? BTU output of outdoor unit? The area of the space being cooled? As the ad says, only blowers are upgraded so outdoor btu remains the same. So i guess it's a worthwhile upgrade so long as you're not using all the aircons at one go.
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Old 04-05-2016, 12:42 PM   #7312
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A lot of assumptions about cost savings from 5 vs 2 tick. Use this calculator. There's another nea link, can't find it now. But it's useful.

There's been much talk about the mitsubishi 5 tick being lousier (lower powered) than the 2 tick because it's 6.6 kW vs 7.52 kW. Find it hard to believe the japanese mitsubishi engineers are as incompetent as people seem to suggest. I doubt it's that simple. Could very well be the 5 tick having a more efficient design and cooling just as well, but using less power.

Assuming air con lasts for 7 years with heavy usage (8 hours daily), system 4 mitsubishi 5 tick (4G28) vs 2 tick (4A28). 5 tick saves $3000


Do your own calculations here:
http://www.e2singapore.gov.sg/Househ...alculator.aspx

More info here:
http://www.e2singapore.gov.sg/Househ...alculator.aspx

If you use the air con for at least 8 hours daily, 5 ticks will surely save you a ton of money across the years.
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Old 04-05-2016, 01:39 PM   #7313
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A lot of assumptions about cost savings from 5 vs 2 tick. Use this calculator. There's another nea link, can't find it now. But it's useful.

There's been much talk about the mitsubishi 5 tick being lousier (lower powered) than the 2 tick because it's 6.6 kW vs 7.52 kW. Find it hard to believe the japanese mitsubishi engineers are as incompetent as people seem to suggest. I doubt it's that simple. Could very well be the 5 tick having a more efficient design and cooling just as well, but using less power.

Assuming air con lasts for 7 years with heavy usage (8 hours daily), system 4 mitsubishi 5 tick (4G28) vs 2 tick (4A28). 5 tick saves $3000


Do your own calculations here:
http://www.e2singapore.gov.sg/Househ...alculator.aspx

More info here:
http://www.e2singapore.gov.sg/Househ...alculator.aspx

If you use the air con for at least 8 hours daily, 5 ticks will surely save you a ton of money across the years.
The calculator is a good easy tool, but it's based on a pretty huge usage pattern, probably a temperature set pretty low or the heat load is high. Heat load high can come from number of pax in the room, high number of electrical appliances, or the walls/floors suck in insulation. (I know some old resale units are really very lossy )


I just quote it and DIY some calculations, better to see it from another angle in terms of efficiency percentage which translates to kWh savings per month/year/7 years.


Panasonic CU-PS12NKZ 2 ticks.
Cooling capacity 4kW. Amps draw 4.2A

Panasonic CU-XS12RKZ 4 ticks
Cooling capacity same 4kW. Amps draw 3.7A

I didn't manage to find 5 ticks for Panasonics.
Both are inverters.

Difference = 13% in electrical consumption between 2 and 4 ticks

If your monthly aircon bill for this 12k FCU is $70 (4-ticks), then it's $79 for the 4-ticks, for the aircon component with a 13% difference. (that's a decent amt of usage - i use much less). Or 108 yearly. Or 756 for 7 years. That is one room with 12k btu/hr FCU (pretty powerful....maybe big MBR)



I use another model that's 9000 btu/hr and folks would be able to relate better with a 9k FCU.

Panasonic CU-XS9RKZ 4 ticks
3.4kW cooling. 2.7A. 840W full load.
(3.2kW cooling needs about 2.55A?)

Panasonic CU-PS9NKZ 2 ticks
3.2kW cooling. 3.3 amps

29% difference between 2 and 4 ticks in this scenario.


If your monthly aircon bill for this 1 room is $60 thereabouts for the 4-ticks, expect $77 for the 2 ticks 9k FCU. $204 diff per year, 1428 diff per 7 years.


How much is $60 worth of electricity? It is 0.1768/kWh now, add 7% gst and it's $0.1892/kWh. $60 is 317kWh, 4-ticks, or 317/30 = 10.56 kWh per day.
The 4-tick system just manages 840W full load, 8hrs usage is just 6.72kWh daily. 3.4kW cooling capacity, or 10,900 btu/hr system.
To get 10.56kWh daily usage so as to achieve that $60 electrical AC bill per room, the operation at full load non-stop would be 12.5 hrs daily



I do not think one can gun the darn 10,900 btu/hr aircon 12.5hrs @ full capacity in a BTO room without freezing to uncomfortable levels. ie set it at 16 deg C


In real life, the aircon usage, at least for me, is way lesser than what is shown by the .gov.sg calculator.
ie just go by percentages. Take a max of 30% (it could just be 13%. whatever). If your bill aircon bill is just $25 per room monthly and you have 2 rooms AC nightly, then it's a $50 AC bill montly.
30% diff is 15 dollars difference. It will be less if it's 13%
7 years = $1260 for these 2 aircon rooms.
(in my case, it's probably lower than even $1000 for 2 rooms over 7 years)

Not sure what is the price difference between the 4 or 5 and 2 ticks system though. But i guess it's less than $1,000 nowadays, last time it was way more i think. So i guess it still pays somewhat to go for the 4 or 5 ticks, all things being equal.
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Old 04-05-2016, 01:39 PM   #7314
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I find that the room's insulation and usage pattern like if the airflow is aimed closer to the pax sleeping position or the usage of a fan at low speed aimed at the pax makes a much bigger difference. (that is if you do not believe the arthritis/rheumatism old wives tale......but srsly if one believes that then he shouldn't even be using air conditioning in the first place lol)

Of coz, there is no problem using a 4-tick or 5 tick system and doing all those in the name of savings.
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Old 04-05-2016, 01:47 PM   #7315
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I think 9k blower and 12k price diff is $100+
If you dont need a bigger cooling capacity no point getting a 12k fcu
I rather they offer extra warranty period. Aircon repair is really very expensive after warranty. The transport, labour, inspection fee alone can burn the pocket.
The only offer for that now would be Daikin, extra 2 years.
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Old 04-05-2016, 01:51 PM   #7316
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Anyway, my real world aircon + electrical appliances usage, with a 2-tick and non-inverter system. 2 aircon rooms usage with occasional 3rd room using. 1 x Plasma TV, 1 x non inverter 2 tick fridge. I'd say the room insulation is excellent. Usually 25 deg C thermostat for the first 1-2 hrs, later set to 26/27 deg C esp during early mornings. Cold enough. Direct airflow to the sleeping position. Weekends are spent at home, 1 room is literally 18-20hrs in operation somemore due to kids sleeping etc.

Usually is about 110 dollars in total, not only air con usage. Peaks at 120+ dollars. There was a big dip last month though, we totally cut away the water heater usage (last time got use bath tub and 100 litres of water, for the kids. )

So that 15-20% electrical consumption diff in aircon usage is not gonna be huge between a 2 tick and 4 tick system. Not at least for me.


GPGT - 4-room BTO.
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Old 04-05-2016, 02:16 PM   #7317
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Oh yeah one more thing....

(1) Cleanliness of your indoor coil
(2) to a lesser extent, cleanliness of your outdoor coil

......are gonna be huge factors in dictating the end efficiency. A drop of 50-65% in cooling capacity is not uncommon for a dirty FCU, while the AC draws the same current/power, inverter or non-inverter 2 ticks 5 ticks doesn't matter at all.

For me I have HEPA filtration for the room (due to allergic rhinitis management) with about 7x ACH and also I DIY clean the indoor coil with pressurised water from a waterpik and aircon foam surfactant, once every 3-8 weeks cycles depending on haze/air quality.
External coil, just hose it down with light to moderate water pressure would do. If you want and it's safe on the AC ledge, you can spray the foam surfactants yearly.

In the 2013 Air Purifier thread, i think some go do steam cleaning too for the outdoor coil. The Before and After did show a big difference though. There probably was/were quite a fair bit of PM from 2013 ahd 2015 haze seasons. These are real life operating scenarios.


For me, it's already proven in the bills....even with a non-inverter and 2 tick system and basically 2 BTO rooms to be cooled nightly. A few folks are doing this in the 2014 Air Purifier thread too. (2013 AP thread is lost/deleted so i can't show you the pics etc)

But note - of course if the 4-tick system is just 200 or 300 dollars more expensive or your usage pattern is SOLID and you like it really cold at 22 deg C with 3 or 4 rooms including living room cooling, then go for it.



People don't do 1 month frequency servicing cycle but more like 6 or 12 months cycle, simply because it'd cost big time. (Some in EDMW mentioned they don't even service yearly)
For me, 1 can of aircon surfactant can use 4 times (4 cleanings per can). About 7 dollars plus per can. Remember to rinse it off though.
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Old 04-05-2016, 02:36 PM   #7318
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And seriously, you can't really buy 1 tick aircons soon liao

http://www.straitstimes.com/singapor...-be-phased-out

PUBLISHED OCT 22, 2015,

In a bid to cut Singapore's energy consumption, the National Environment Agency (NEA) will phase out less energy-efficient air-conditioners by September next year (2016).

From September next year, however, the Minimum Energy Performance Standards (MEPS) will be raised and all models here will be required to have at least two ticks.
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Old 04-05-2016, 02:42 PM   #7319
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I read some 9k -> 12k system upgrades.

Be careful of using a 12k FCU in a small MBR of new BTOs. It might be sized too big.
This causes higher RH % levels.

Not a local article, but it gets the idea across.

http://www.energyvanguard.com/blog-b...-Is-a-Bad-Idea


The converse is true. Undersizing an aircon causes low humidity but insufficient cooling.

You can try to use 2 x 9000 btu/hr aircon FCUs from 2 rooms. Third Bedroom you close the door. The 2 bedrooms with 9k FCU open the doors and use 2 fans to pump the air to the living room. Observe your thermo/hygrometer. Temperature would not drop a lot, but RH% would drop a lot.

This is because the coils are working 100% and very much maintained below the dew point temperature, but the cooling btu/hr is insufficient.
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Old 04-05-2016, 02:43 PM   #7320
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If you use the air con for at least 8 hours daily, 5 ticks will surely save you a ton of money across the years.
Where do you get 5-tick just $600 more than 2-tick?

Anyways, using the price I paid for my 2-tick and trying all 3 options i.e. light medium and heavy usage, I will spend more in the long run, but then long run = over 7 years. And with light usage (i.e. about 2 months worth of every-night usage) the difference is just a few dollars, and the 2-tick is supposed to be quieter and cools down faster, so I'm fine with paying that few dollars more.

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