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T8621A,C,D
GLOSSARY
Glossary
Comfort temperature
The temperature desired when active and occupying
the building.
Energy-saving temperature
The lower (heating) or higher (cooling) temperature
that allows savings on heating and cooling costs when
asleep or away. Also called the setback (heating) or
setup (cooling) temperature.
Preprogrammed schedule
This is the schedule programmed into the thermostat at
the factory. It sets a night program that provides energy
savings when owner sets no program, or if personal
program is lost for any reason. The program, which is the
same for all days of the week, is:
Start Temperature
Period Time Heating Cooling
MORNING 6:00 AM 70° F78° F
MIDDAY ——— No program —————
EVENING ——— No program —————
NIGHT 10:00 PM 60° F78° F
Program
The times and temperatures owner sets to define the
comfort and energy saving periods for each day schedule.
Recovery
The time when the thermostat operates the heating or
air conditioning equipment to return the building from the
energy saving temperature to the comfort temperature.
The thermostat starts the recovery period early so the
building will be at the comfort setting by the time the
owner has chosen.
Setback
Reducing the temperature in the building for a set
period in heating for energy savings. The lower tempera-
ture is the energy savings temperature.
Setup
Raising the temperature in the building for a set period
in cooling for energy savings. The higher temperature is
the energy savings temperature.
Setpoint
The thermostat temperature setting the owner selects.
The thermostat turns the heating or cooling equipment on
and off to maintain this temperature at the thermostat
location until another temperature setting (setpoint) goes
into effect.
SYSTEM light
This light glows whenever the thermostat is calling for
heating or air conditioning.
Time period
One of four program periods: MORNING, MIDDAY,
EVENING and NIGHT available with the Chronotherm
III Thermostat (one period begins when the previous
program period ends):
MORNING—The time period when the owner brings
the building to a comfortable temperature to begin the
day. This is the only period that must contain a time and
temperature for each day.
MIDDAY—The time period when the owner can set-
back heating or setup the cooling temperature for day-
time energy savings if the building is unoccupied.
EVENING—The time period when the owner wants
the building at a comfortable temperature for evening
activities after daytime energy savings.
NIGHT—The time period when the owner can setback
heating or setup the cooling temperature for energy
savings because family members are asleep or the
building is unoccupied. Often a NIGHT energy savings
temperature is set only for the heating season so family
members can sleep cool in summer.