Manual Thermal Control Is Always Best!

  
The finer points of thermostats are actually much more complicated than any published article covers. You must study each premium thermostat individually. If it does not have settings for swing, deadband, fan delays, early recovery, proper setbacks, etc., it's not really of good use. Dual fuel setups are even more complicated because you must decide whether to use the thermostat or the fossil fuel controller function for balance point control. You must also decide on an economic or thermal balance point.  
  
If you actually live in the house, you may adjust a dual fuel setup to your preferred balance point. If you are an installer, you may be tempted to guess at a balance point, the same as guessing at the sizing of the HVAC units. If you are a designer, you will have your own methods for sizing and setup, with lots of room for discussion, and possibly,  imprecision. A homeowner without degrees in physics, chemistry, and business is at a total loss to understand their home climate system today!  
  
Manual thermostat control always results in the lowest costs and optimum comfort. No thermostat out there can compete with a trained human! The Nest thermostat has serious flaws, as does its competitor, the Honeywell Prestige thermostat. The ideal thermostat for all setups has yet to be produced or exist.