Quote Originally Posted by Thermatech View Post
A typical split system in Japan historically had fixed speed compressor & capillary.
VRV / VRF pioneered inverter drive compressor speed control & now this has also become standard on small split systems.
The old type fixed speed compressor system will switch the off every time it gets to set point.
With VRV the indoor unit will tend to match the heat load & does not switch off at set point so often.
Mitsubishi Electric City Multi VRF take this one step further as each indoor unit is programmed for 'energy save mode'
At 2 deg C from set point the indoor unit considers that the room air is approching set point & sets a new target SH, which in turn results in the electronic expansion valve ramping down to reduce refrigerant volume.
When the retern air gets to 1 degC from set point the indoor unit now considers the room air temperature is at the comfort zone & now sets another target SH which results in the electronic expansion valve remping down to minimum opening setting.
In part load conditions this meens that the indoor unit spends most of the time in energy save mode & almost never actually stops cooling.
For the mitsubishi system, does the fan speed ramp down when the targeted super heat is adjusted?

If not the energy savings mode is BAD for a humid climate because coil apparatus dew point has a large potential to climb above the entering air temperature. At this point the coil is only doing sensible cooling. This potential will rise as the difference between the acutal load and the capcity of the system increases.

Thermatech, does the Daikin VRV III system ever change the targeted superheat, like the mitsubishi city multi system?