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Old 19-01-2017, 09:00 PM   #9269
Join Date: Nov 2016
Posts: 262
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?


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.
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