Air conditioning - Any recommendations please?? - Part 2

[BanEle]

I am suggesting to get MKS65 or MXY3G28. As their rated capacity is 20-21k and you turn on 2 bedrooms most of the time, you can consider to upgrade one of the 9k indoor unit to 12k. This will allow you to maximise the rated capacity of 20-21k from these 2 outdoor units.

If you choose to keep to 9k for all bedrooms, it is ok too. Since you turn on 2x9k most of the time, it is within the 20-21k rated capacity. No performance loss.

However, upgrading 9k to 12k usually is very affordable. Some air con company even throw in free. So, can consider.

Are you suggesting upgrade master bedroom indoor unit? I often seee this recommendation. Curious ah but why? If Mbr and another room same size. Should it be use both room same btu and upgrade compressor outside?

 

[OneMantou]

I was told by sales guy that 12000 - 18000 BTU is needed for big room (2 small rooms combined to 1 room)..

But this is not consistent with what I read online? I searched a few sources and tried a few methods like BTU= sq feet x 25 or 35; add 500-600BTU per person; checking up reference table for room size (abt 220sqft) and BTU...

9000 BTU seems more than enough. What am I missing ?

Example reference table:
https://www.oasis-aircon.com/blog/what-is-aircon-btu-and-how-to-use-it-to-choose-the-right-aircon-for-you

 

[BanEle]

If you check sg energy efficient website, it say just use area divide by 5. And i think this is very accurate. Sure safe one.

https://www.e2singapore.gov.sg/over...y-at-home/sizing-your-air-conditioning-system

 

[wongminmin]

I was told by sales guy that 12000 - 18000 BTU is needed for big room (2 small rooms combined to 1 room)..

But this is not consistent with what I read online? I searched a few sources and tried a few methods like BTU= sq feet x 25 or 35; add 500-600BTU per person; checking up reference table for room size (abt 220sqft) and BTU...

9000 BTU seems more than enough. What am I missing ?

Example reference table:
https://www.oasis-aircon.com/blog/w...-to-use-it-to-choose-the-right-aircon-for-you

to their mentality having more is better than having less. However, it also mean more maintenance and electricity bill for u.

Like mbr can use 9k btu....but some will go for 12k....

the factors choosing correct btu...
-using for daytime or night time (ambient temperature)
-numbers of heat emitting devices in the room (room temperature)
-numbers of person in the room
-number of doors & windows
-desire temperature... i use 24,but my frd must use 18 to feel cold.
-room size
-ceiling height
-aircon unit position etc.


reference

9k BTU – 15sqm to 18sqm (HDB/Condo Common rooms)
12k BTU – 20sqm to 24sqm (HDB/Condo Master rooms)
18k BTU – 30sqm to 36sqm (4 room flat Living rooms)
22k/24k BTU – 40sqm to 44sqm (5 room flat/ Condo Living rooms)

This question hard to answer already. I suppose the electricity consumption is the same because if the amount of heat in a room is the same, the 18k only remove the heat faster den the 9k but the total heat removed is the same.

There are other ways to save electricity such as prevent excess heat from entering the room such as double glazed windows, solar films, cover all gaps between doors and windows, insulating walls etc.

 

[OneMantou]

If you check sg energy efficient website, it say just use area divide by 5. And i think this is very accurate. Sure safe one.

https://www.e2singapore.gov.sg/over...y-at-home/sizing-your-air-conditioning-system

Thanks.. based on this the calculation is 18K.. I think adjusted for SG equatorial weather. I checked another source from Msia ,also about 17-18K.

to their mentality having more is better than having less. However, it also mean more maintenance and electricity bill for u.

Like mbr can use 9k btu....but some will go for 12k....

the factors choosing correct btu...

Spoiler

-using for daytime or night time (ambient temperature)
-numbers of heat emitting devices in the room (room temperature)
-numbers of person in the room
-number of doors & windows
-desire temperature... i use 24,but my frd must use 18 to feel cold.
-room size
-ceiling height
-aircon unit position etc.

reference

Thanks! Yeah am going to double glaze my room windows. I think it's picking the lesser of evils cos a lower BTU unit needs to work harder and a too high BTU causes humidity issues . (From my reading). 25deg was enough for me when I use aircon in Bangkok weather. Maybe I'll just whack 12K BTU

 

[light84]

Look at room insulation also rather than BTU

BTU just gives u indication on how fast the heat is removed from the room but if some heat keep leaking into the room, of course aircon runs harder to remove that extra heat, waste $$$

I bought some silicon and brush strip to seal off all the door gaps and window gaps, insulate wall by sticking a decorative foam panel on exterior facing wall of bedroom, pull a long curtain at the walk in wardrobe as it was previously exposed.

After I did above, it reduce time to cool the room to desired temperature by 30%, saving electricity $$

 

[akdwivedi]

I hear sg Govt is banning R410 based AC from 2022. But none of manufacturers offers R32 based system 3 or system 4.

 

[Alphas]

Nea states the ban on R410A will begin at Q4 2022 for new installations, existing air con can still continue to use the same refrigerant. Daikin and and Toshiba have aircon that use the newer R32 refrigerant. Daikin Envi Series and the Toshiba YouMe Series runs in R32 refrigerant.

 

[light84]

I was reading the Toshiba UK FAQ on R32. Very surprised at the following;

Can I use flare connections inside for R32?

Importantly the refrigerant connections to the indoor unit must be brazed and flare connections are not allowed.

So how to chemical clean next time? Cannot disconnect the connection ... Wow ..

 

[cheongking888]

Could anyone care to enlighten me where did the old refrigerant go to while replacing the compressor?

I have been having few sleepless night after the Daikin Technician came and changed my aircon's compressor. I saw him pumped in new 410 with a weighting machine.

 

[light84]

Could anyone care to enlighten me where did the old refrigerant go to while replacing the compressor?

I have been having few sleepless night after the Daikin Technician came and changed my aircon's compressor. I saw him pumped in new 410 with a weighting machine.

Discharged to atmosphere .. It's illegal but everyone does that .. I have not seen any technicians carrying a refrigerant recovery machine to store the old refrigerant temporarily

 

[Mecisteus]

If you check sg energy efficient website, it say just use area divide by 5. And i think this is very accurate. Sure safe one.

https://www.e2singapore.gov.sg/over...y-at-home/sizing-your-air-conditioning-system

Good enough if room is standard height.

The website should put this in their disclaimer.

 

[micgoh]

Hi is Panasonic a/C good? Looking at system 3

 

[GBC]

Hi is Panasonic a/C good? Looking at system 3

Actually brand is one thing, people here generally will tell you Mitsubishi Starmex is best..(reason reliable, cheap spare parts etc) followed by Daikin. However, there are also people who have alot of problems with their starmex and daikin problems. so it's a matter of whether you are lucky or not to get a lemon system.

but the other more important factor to consider is who is the contractor who is installing your aircon system. Get a bad installer and you will get aircon problems thru out the life of your aircon system. Get a good installer and you will have a relatively problem free aircon system.

Panasonic brand aircon has been in the market for more than 40 years and if the aircon is lousy, I don't think it would have survive until now.

 

[petetherock]

Actually brand is one thing, people here generally will tell you Mitsubishi Starmex is best..(reason reliable, cheap spare parts etc) followed by Daikin. However, there are also people who have alot of problems with their starmex and daikin problems. so it's a matter of whether you are lucky or not to get a lemon system.

but the other more important factor to consider is who is the contractor who is installing your aircon system. Get a bad installer and you will get aircon problems thru out the life of your aircon system. Get a good installer and you will have a relatively problem free aircon system.

Panasonic brand aircon has been in the market for more than 40 years and if the aircon is lousy, I don't think it would have survive until now.

+1 on the installer.
If the pipes are not well done, even if you get tip top materials or a good brand it will still give you issues.
All three brands are generally fine.

Other factors like not underpowering your home is more important.
Short pipe runs, and good siting of the blowers matter too.

 

[wokhei]

You tried using your remote control to look for error code by pressing on 'cancel' button.

If it is still under warranty, they won't charge.

No error code leh. But still not cold... I setup another appointment but I guess they will charge? Currently it is only under compressor warranty.

 

[OneMantou]

Im reading up on aircon gas top-up. Strangely the results on my searches are mostly local pages on this generic topic. Out of curiosity I searched for UK and Australia examples and don't see such services popping up as commonly for non-cars. In fact, topping up of aircon refrigerant in Aust is not allowed until leaks are checked for.

https://www.arctick.org/media/1186/arc_fact-sheet_15.pdf

https://www.fujitsu-general.com/uk/support/faq/split/0212.html

What is it with the local scene that somehow it seems like whatever aircon problem is to refill gas? how we use the aircon until leak gas?

 

[wongminmin]

Hi is Panasonic a/C good? Looking at system 3

most of the time is just the installer issue...not the brand.

e.g poor workmanship.....gas leaking during the first month.
e.g exposed wire....few years later....this issue start surfacing.

u can look at neighbour...what brand they are using......it is very obvious the market share....

 

[wongminmin]

No error code leh. But still not cold... I setup another appointment but I guess they will charge? Currently it is only under compressor warranty.

try to find those experienced guys.... they 1 look...know the root.


some charge per visit for troubleshooting
some don't charge for troubleshooting

 

[light84]

Im reading up on aircon gas top-up. Strangely the results on my searches are mostly local pages on this generic topic. Out of curiosity I searched for UK and Australia examples and don't see such services popping up as commonly for non-cars. In fact, topping up of aircon refrigerant in Aust is not allowed until leaks are checked for.

https://www.arctick.org/media/1186/arc_fact-sheet_15.pdf

https://www.fujitsu-general.com/uk/support/faq/split/0212.html

What is it with the local scene that somehow it seems like whatever aircon problem is to refill gas? how we use the aircon until leak gas?

Cos customers are ignorant .. Contractors monkeys see monkey do .. if competitor offer free gas top up but u dun, lose out lor

Gas not need top up if no leak .. u dun top up gas for fridge right? My fridge run 10 years 24 hours oso no need top up gas