If the indoor temperature is less than the desired temperature, then the optimum start time is:

OB + (d x HC) - ((d * f * HT) / 25) + AB

Where:

OB

=

Occupancy begin time from SSTO command.

d

=

Indoor temperature minus the desired temperature.

HC

=

Heating coefficient (hcoef1) from SSTOCO command.

f

=

Outdoor temperature minus the desired temperature.

HT

=

Heating transfer coefficient (hcoef3) from SSTOCO command.

AB

=

Adjust begin time from SSTO command.

If the indoor temperature is greater than or equal to the desired temperature, then the optimum stop time is LB:

Where:

LB

=

Latest begin time from SSTO command.