Air-source heat pumps, including ductless systems, extract and transfer heat energy between the air outside and inside the home. So, outside air temperatures and the location of the indoor AHUs affect heating and cooling efficiency (particularly heating efficiency). Here’s a few professional tips for setting the thermostat for maximum energy savings and comfort.
Setting the Thermostat
- AHU location: Universal high-wall and ceiling mountings are popular installation locations for the indoor AHUs. However, the temperature sensor located on the AHU, which may be 7-10 feet from the floor, is going to read warmer air temperatures than what you actually feel closer to the floor, such as when you are sitting in a chair. So, if you set the thermostat to 68 degrees, for instance, but it feels much cooler, increase the temperature as needed until you find the sweet spot.
- Energy savings: The Energy Star program suggests setting the thermostat to 68 degrees during the heating months and 78 degrees during the cooling months. Whichever temperature you prefer for comfort, be sure to use sleeping and working hours to turn-back/up the thermostat setting to save energy. For sleeping hours, try turn-back/up temperatures of 4-6 degrees, and 10-15 degrees for working hours.
- Mode changes: If your ductless system has more than one indoor AHU and only one outdoor cabinet (compressor), your ductless system is a multi-split configuration. All indoor AHUs must be in the same mode when running off the same compressor. So to adjust the mode between heating and cooling, turn off all AHUs beforehand, change the mode setting, and turn on the appropriate AHUs.
- Advanced features: All of the preceding suggestions for setting the thermostat correctly are performed automatically with new advanced ductless systems. For instance, a new Mitsubishi Electric mini split offers digital temperature scanning, automatic mode changeover, and an exclusive two-piping system for simultaneous heating and cooling (multi-split system).
For more details about setting the thermostat correctly for your ductless mini split, or to see if a ductless system is right for your home, please contact us to speak with a certified Mitsubishi Electric Contractor in your area.