Air conditioning - Any recommendations please??

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i-Movies

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looking for the quietest Air Con, both Daikin and Mitsubishi claim their products' decibels rating are as low as 19 dB, which one feels more quietest based on your experience?
 

ragegoh

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Do i need to submit any docs to hdb regarding my aircon installation? I read online that we have to submit an installation report after installing?
 

dachee

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Do i need to submit any docs to hdb regarding my aircon installation? I read online that we have to submit an installation report after installing?

Hi,

The answers provided in this forum are not official reply and therefore it would be good that you officially write to the relevant authority on your question and keep a copy of their reply in your file for future reference.

The above are my opinion and hope that they are helpful.
 

dachee

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looking for the quietest Air Con, both Daikin and Mitsubishi claim their products' decibels rating are as low as 19 dB, which one feels more quietest based on your experience?

Hi,

It is difficult to provide you an answer as home owners do not have both air conditioners (FCUs) of the stated brand in the same operating condition for comparison.

The sound levels are tested in according to specific environment conditions. In general, 19dB is soft in relation to most environment sound. But again, some people may have sensitive hearing that can pick up very low dB level and frequency, for example young children.

Another consideration is the environment noise. For example, if you are living next to a road with consistent traffic, then, the noise from the traffic may cover up the noise from the FCU (even with the windows closed). And the 19 dB level is no more important.

You may wish to check this link on environment sound level: https://www.cdc.gov/nceh/hearing_loss/noise_sources.html

The above are my opinion and hope that they are helpful.
 

jason910

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Hi,

I am looking at these two combos.

1. MXY-4A38VA/MSY-GE18A + GE10VA X 3

2. MXY-4A28VA/MSY-GE18A + GE10VA X 3

Mine is a new 4-room BTO, I understood that 28VA would be sufficient as the max aircon that I would on is 2. Most of the time it would be just the MBR. I'm thinking of getting the MXY-4A38VA as I prefer and think that with a higher capacity BTU I can get more suppprt if I on more then 2 units of FCU? What would be the difference for 38VA and 28VA? Thanks
 

dachee

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Hi,

I am looking at these two combos.

1. MXY-4A38VA/MSY-GE18A + GE10VA X 3

2. MXY-4A28VA/MSY-GE18A + GE10VA X 3

Mine is a new 4-room BTO, I understood that 28VA would be sufficient as the max aircon that I would on is 2. Most of the time it would be just the MBR. I'm thinking of getting the MXY-4A38VA as I prefer and think that with a higher capacity BTU I can get more suppprt if I on more then 2 units of FCU? What would be the difference for 38VA and 28VA? Thanks

Hi,

From the configuration provided, you have 4 rooms needing cooling. 3 Bedrooms and a living room/dinning room.

In my opinion, there are 4 factors that need to be considered.

1. The capacity sizing'
2. The shape and placement of the FCU/s in each room,
3. Sound level
4. The room temperature setting that you would use,
5. The normal rating when various combination of FCUs are turned on.

1. The GE10VA FCU provides up to 2.5kW or 8.53k Btu, which is sufficient for most if not all HDB rooms size. The 2.5kW FCU can even take room size of 5X5X2.8m (ie area of 25m and ceiling height of 2.5m) with temperature of 13 degrees C different from outside temperature.

2. The placement of the FCU is very important to the way the room is cool.

2.1 Placing the FCU at a corner will restrict the air flow to some parts / corners of the room. The most difficult areas to cool in the room are the corners nearest to the FCU (ie to the left or right of the FCU). When the FCU is placed equally from these 2 corners, it reduces that difficulty for the cool air to reach these places. Placing the FCU at one corner may hamper the air flow to the other corner, living it as the warmest area within the room. Temperature within various parts of the room vary too much such that cooling the warm corner may cause the other areas to be too cold.

2.2 It will also affect the suction of the returned air flow into the FCU and therefore the temperature control of the system. The location of the FCU in a room affects the return air path and the areas where the return air is coming from. A good location will provide a uniform return air from all parts of the room that provides a uniform temperature (with the least temperature difference) of the room. When cold air from one section of the room is returned to the FCU, while other parts of the room is still warm, the system temperature control received that the signal that the room is cool and therefore reduces it cooling capacity, causing hot and cold areas within the room. Some air conditioner uses the remote control to sense the room temperature and transmit the result to the FCU for system management. However, with this, there will still be hot and cold areas in the room if the FCU is incorrectly placed.

2.3 Sometime, the room may have a "L" shape, specially in the living /dinning room. Such shape will affect where the cool air can reach and with only one FCU, it is likely that some areas of the such room will not be cold to the desired temperature unless the whole room is cooled down which may take some time or in some situation not at all when the system capacity is reduced as explained in above point 2.2. In addition, the operating cost in such layout would likely be more than having two well placed FCUs. Two well placed FCUs with lower capacity than one higher capacity FCU can provide better temperature control and faster cooling to the desired cooling areas. This is because such layout can take advantage of direct cooling and as well as better temperature uniformity.

So instead of having one GE18VA which is a capacity of 5kW and placing it at one end of the room with limited air flow to the furthest corner of the "L" shape room, you may wish to have two GE10VA place at each ends of the "L" shape room.

You may wish to know that the GE18VA is of the same size as the GE10VA though the air flow at high setting are 15.1 and 11.4 CMM respectivity. Is 15.1 CMM sufficient to reach the end of the "L"?

Would you like to keep running your GE18VA at high speed to keep the furthest corner cool?

3. Sound level. The sound level for the GE10VA is 19 dB, while that of the GE18VA is 28 dB. At 19 dB, it is really quiet and this is the selling point of the ME and Daikin air conditioners. But these are at low speed. So when you run your GE18VA at high speed, you will be subjected to 49 dB instead of 28 dB as you need to cool those further areas.





....... to be continued.
 
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jason910

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As usual thank you very much for your exceptionally detailed explanation. Do i need a MXY-4A38VA or MXY-4A28VA?

In future if i need to on more units example i will have the capacity to do so instead of having the MXY-4A28VA but unable to upgrade it etc? What is the differences in having a MXY-4A38VA or MXY-4A28VA?

Thanks

Hi,

From the configuration provided, you have 4 rooms needing cooling. 3 Bedrooms and a living room/dinning room.

In my opinion, there are 4 factors that need to be considered.

1. The capacity sizing'
2. The shape and placement of the FCU/s in each room,
3. Sound level
4. The room temperature setting that you would use,
5. The normal rating when various combination of FCUs are turned on.

1. The GE10VA FCU provides up to 2.5kW or 8.53k Btu, which is sufficient for most if not all HDB rooms size. The 2.5kW FCU can even take room size of 5X5X2.8m (ie area of 25m and ceiling height of 2.5m) with temperature of 13 degrees C different from outside temperature.

2. The placement of the FCU is very important to the way the room is cool.

2.1 Placing the FCU at a corner will restrict the air flow to some parts / corners of the room. The most difficult areas to cool in the room are the corners nearest to the FCU (ie to the left or right of the FCU). When the FCU is placed equally from these 2 corners, it reduces that difficulty for the cool air to reach these places. Placing the FCU at one corner may hamper the air flow to the other corner, living it as the warmest area within the room. Temperature within various parts of the room vary too much such that cooling the warm corner may cause the other areas to be too cold.

2.2 It will also affect the suction of the returned air flow into the FCU and therefore the temperature control of the system. The location of the FCU in a room affects the return air path and the areas where the return air is coming from. A good location will provide a uniform return air from all parts of the room that provides a uniform temperature (with the least temperature difference) of the room. When cold air from one section of the room is returned to the FCU, while other parts of the room is still warm, the system temperature control received that the signal that the room is cool and therefore reduces it cooling capacity, causing hot and cold areas within the room. Some air conditioner uses the remote control to sense the room temperature and transmit the result to the FCU for system management. However, with this, there will still be hot and cold areas in the room if the FCU is incorrectly placed.

2.3 Sometime, the room may have a "L" shape, specially in the living /dinning room. Such shape will affect where the cool air can reach and with only one FCU, it is likely that some areas of the such room will not be cold to the desired temperature unless the whole room is cooled down which may take some time or in some situation not at all when the system capacity is reduced as explained in above point 2.2. In addition, the operating cost in such layout would likely be more than having two well placed FCUs. Two well placed FCUs with lower capacity than one higher capacity FCU can provide better temperature control and faster cooling to the desired cooling areas. This is because such layout can take advantage of direct cooling and as well as better temperature uniformity.

So instead of having one GE18VA which is a capacity of 5kW and placing it at one end of the room with limited air flow to the furthest corner of the "L" shape room, you may wish to have two GE10VA place at each ends of the "L" shape room.

You may wish to know that the GE18VA is of the same size as the GE10VA though the air flow at high setting are 15.1 and 11.4 CMM respectivity. Is 15.1 CMM sufficient to reach the end of the "L"?

Would you like to keep running your GE18VA at high speed to keep the furthest corner cool?

3. Sound level. The sound level for the GE10VA is 19 dB, while that of the GE18VA is 28 dB. At 19 dB, it is really quiet and this is the selling point of the ME and Daikin air conditioners. But these are at low speed. So when you run your GE18VA at high speed, you will be subjected to 49 dB instead of 28 dB as you need to cool those further areas.





....... to be continued.
 

dachee

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As usual thank you very much for your exceptionally detailed explanation. Do i need a MXY-4A38VA or MXY-4A28VA?

In future if i need to on more units example i will have the capacity to do so instead of having the MXY-4A28VA but unable to upgrade it etc? What is the differences in having a MXY-4A38VA or MXY-4A28VA?

Thanks

Hi,

In short, yes, the 4A38VA has higher capacity than the 4A28VA with better performance of full load COP of 3.63 against the latter of 3.44.

The total cooling capacity for the 10+10+10+18 FCUs is 1.6+1.6+1.6+3.2 = 8kW for the former and 1.5+1.5+1.5+2.7 = 7.2kW for the latter for HDB with limited current. Private dwelling and some HDB do not have limited current. You can check this with HDB.

Looking at the increase in heat removal of the GE10VA FCU of 1.6-1.5kW = 0.1kW between using the 4A38VA and the 4A28VA. The difference of 0.1kW for a room size of 4MX3MX2.8M is only 1 degree C. Meaning that you would likely be able to cool the room by only 1 degree lesser from using the 4A28VA to 4A38VA.

The GE18VA FCU will have greater difference of 3.2 - 2.7 = 0.4kW, giving a temperature difference of about 2 degree C for a room size of 4mX6.5mX2.8m. Similar to above, you can only reduce 2 degree C more when using the 4A38VA than the 4A28VA.

However, you may wish to know that you may not even use 1.5kW from the FCU in your bedroom of size 4mX3mX2.8m, as 1.5kW would reduce the room temperature to 22 degree C when the outside temperature is 35 degree C (ie a difference of 13 degree C). Most of the time, Singapore mean daily max temperature is between 30 to 32 and daily average of 26 to 28 degree C and taking the temperature of 13 degree C difference that the 4A28VA can achieve, your room coldest temperature would likely be 26-13 = 13 degree C. However, this temperature of 13 degree C is unlikely to be reached as your remote control temperature setting is only up to 16 degree C. In addition, 22 degree C would already be too cold for most people.

In most cases, people would set their temperature to 25 or 26. At this temperature, you only need a 3 degree C difference, using only 0.5kW from the FCU.

The decision is still up to you as you are using the GE18VA which you may need to turn on high to cool the living and dinning room.

The above are my opinion and hope that they are helpful.
 

jason910

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To Dachee: yes your detailed explaination is very very helpful and I really appreciate it. Thanks a lot
 

BenBen010103

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What's the recommendation for a 5-room flat? Sys 5 or 2+3, or just sys 4 will do?

Setup 1

sys3:
2 common room - 9k btu
living room - 12k btu
sys2
MBR - 12k btu
dining room - 9k btu

Setup 2

Sys5
common room - 9k btu
MBR - 9k btu
Living Room - 12k btu
dining room - 9k btu

Setup 3

Sys4
common room - 9k btu
MBR - 9k btu
living room - 12k btu

Or any other suggestions?
Technically, is it looking the btu of the compressor will tell me how many unit I can switch on simultaneously by adding each unit's btu?
 

Crexzz

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Is there any compelling reason why toshiba isn't talked abt in here?

I've noticed that though the label shows 4 ticks only but kwh value is lower then mitsubishi 5 ticks. Why is this so?

And personally, I've experienced toshiba system that lasted 10 years without any issue.

Hope someone can enlighten me
 

d3n

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anyone bought aircon and installed by TimWong from renotalk, any reviews about his installation? :s12:
 

NeonX

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Anyone can recommend shop to purchase and install daikin smile series of air conditioners?
 
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