~What Honeywell Says

Your new thermostat is so smart, it’s almost human. You perceive temperature from a variety of sources, not only from the air in the room, but also from your surrounding walls, windows and furnishings. Humans feel differences in temperature as slight as two degrees Fahrenheit. Common household thermometers and standard thermostats sense only air temperature, which may not reflect how hot or cold the room actually feels to you. Your new thermostat reads both the temperature of the wall and in the air, and responds to temperature changes as little as one degree Fahrenheit, so room temperature is more likely to feel right to you and your family. The thermostat acts like a computer. When calculating the time to turn on your heating or cooling system, it considers air temperature, wall temperature, and the time you want to reach the comfort temperature.

 After considering these three things, Adaptive Intelligent RecoveryTM control gradually changes the temperature from the energy savings setting to the comfort setting (for example, from a heating temperature of 62° at night to 70° in the morning). The system runs until the comfort temperature you choose is reached without overshooting the setting. This saves energy. How do you know when the system is in recovery? The thermostat displays “Recovery” whenever the thermostat activates Adaptive Intelligent RecoveryTM control. So, “Recovery” displays during the recovery time from Sleep to Wake and from Leave to Return.

 After installation or new schedule programming, your thermostat learns from experience. Each day it checks how closely it hit the recovery target (for example, 70°at 6:00 AM) and adjusts the next day’s recovery start time accordingly. After four to eight days, the thermostat has adjusted to local weather, your lifestyle, the construction of your home, and your heating and cooling system.

~Another Source States.

This feature allows the thermostat to “learn” how long the furnace and air conditioner take to reach programmed temperature settings, so the temperature is reached at the time you set.
For example: Set the Wake time to 6 am, and the temperature to 70°. The heat will come on before 6 am, so the temperature is 70° by the time you wake at 6. The message “Recovery” is displayed when the system is activated before a scheduled time period.

~What EnergyStar has to say.

Cranking your unit up to 90 degrees or down to 40 degrees, for example, will not heat or cool your house any faster. Most thermostats, including ENERGY STAR qualified units, begin to heat or cool at a programmed time, to reach set-point temperatures sometime thereafter. Units with adaptive, “smart,” or “intelligent” recovery features are an exception to this rule — they reach desired temperatures by the set time, since they use formulas that are based on your historical use.

~What GE Controls Company had to say at an EnergyStar meeting on 2-Feb-2006.

 Conventional Recovery – Considered as a minimum feature. It does not lend itself to maximum energy efficiency. Users must set the initiating time ahead of their normal WAKE time for the house to be warm. As the outdoor temperatures change during a season, the initiation time may come sooner than outdoor conditions require, so energy is wasted.

 Adaptive Recovery – This is the preferred recovery type for maximum energy savings. It starts the system ahead of the programmed time , and completes the recovery at the programmed time, taking into account changes in outdoor temperature during the season. There are several types of Adaptive or Intelligent Recovery designs on the market, each using feedback information from previous recoveries or other calculations to determine the next initiation time. Some are totally adaptive and some are partially adaptive. Continuous running of the equipment during recovery eliminates the user complaint that cycling of the system during recovery is annoying during sleep hours. Adaptive Recovery should be the default or preferred type.

 Heat pump Systems with Auxiliary Heat - For heat pumps with auxiliary heat, there should be a requirement for a means to hold off the auxiliary heat during the recovery unless required to complete the recovery at the programmed time. There is no need to use auxiliary heat for recovery if the heat pump alone can complete the recovery. Unnecessary use of auxiliary heat wastes energy.

~To Be Continued~