I was reflecting on the comment regarding the ‘1 degree maintenance band’ operating philosophy of the Nest thermostat. In most circumstances, there are significant operational benefits of the digital design and features of the smart thermostats compared to the simple switching design of a mechanical thermostat. However, the ‘maintenance band’ of the mechanical thermostat does not change when just the indicator scale of the thermostat changes. The one degree maintenance band of the Nest thermostat operating in Celsius mode delays the onset of heating or cooling by the equivalent of an extra 0.8 degrees Fahrenheit because of how the firmware is designed. In my circumstance - using a Nest Remote Temperature Sensor in a usually occupied area of the home - the maintenance band is not just the one degree differential, it is also affected by the time interval between sequential temperature readings from the remote sensor. This past winter in extremely cold weather, I had noticed the occasional circumstance where the remote sensor monitoring the heat loss of my home was not sensing a sufficient temperature loss to trigger the furnace to turn on at one temperature update. By the time the remote sensor transmitted the next temperature update, the temperature loss at the remote sensor had increased by another 0.5 degrees Celsius, which effectively increased the Maintenance Band to almost 1.5 degrees Celsius ( or about 2.7 degrees Fahrenheit). To compensate for the increased heat loss, I had to increase the Nest thermostat comfort setting by 1.0 degrees Celsius during the colder weather. I appreciate the opportunity in this forum to express my concern about the Nest thermostat system. I will continue to operate my Nest system in Celsius mode because it is now familiar to me, and an operational change to Fahrenheit mode will be harder to explain to my life partner. If I tried to explain it, my handle would need to change to NotEnufFreeTime.
