Rockwell Automation FANM FanMaster Energy Saving Package - Manual (Page 17)

FanMaster Overview 1-11
Allen-Bradley® FanMaster™ Energy Saving Package Installation Manual - Publication FANM-IN001B-EN-P – December, 2009 PN-65329
Specific Setup Values
This section provides additional information for setting up specific
FanMaster configuration fields. The values entered in these fields help the
energy calculator to perform a more accurate estimate of energy savings and
are not used by the basic control algorithm and will not affect actual
savings.
• Heating Efficiency % - Use the manufacturer’s data sheet for the HVAC
unit to determine this efficiency. This value is a measure of how
efficiently the BTU capacity of the fuel purchased is converted into an
actual BTU delivered to the heated room. This value may be listed as an
AFUE (Annual Fuel Utilization Efficiency) rating. If this value is not
available, you may simply use the default value of 87% or adjust the
value up or down about 10% based on the age of the equipment (older
units typically having a lower efficiency).
• Minimum Damper Pos % - This value can best be approximated by
visually determining the angle or degree of openness of the outside air
damper in normal operation. 0% represents a damper fully closed and
100% represents a damper fully open. Typically, the damper will be
controlled by the existing HVAC or BAS system to about 10% open. If
desired, you can use a protractor to determine the actual angle and
convert it to a percentage, taking into account that dampers often appear
to be several degrees off-vertical when fully closed due to their
overlapping position. This value ultimately determines the percentage of
the total unit flow which is outside air and thus requires heating and
cooling to bring to a suitable room temperature.
Because the regulating effect of damper position on the volume of
airflow is very difficult to determine under the best of conditions, the
actual flow volume of outside air can only be roughly approximated by
this setting. However, a change in the setting of 1 or 2 percent will have a
10 or 20 percent effect in the estimations of the heating and cooling
BTU’s saved by FanMaster; so try to be as accurate as possible. This
value is used in the estimation of savings only and therefore does not
affect the actual realized savings.
• CO
2
Demand Setpoint ppm - If the CO
2
sensor reports a value greater
than the setpoint, FanMaster allows the HVAC fan to increase to 100%
and will stop any override of the normal damper position. Outside air has
a typical range of 300 to 400 ppm CO
2
. When the added outside air
returns the interior CO
2
level to the setpoint minus 50 ppm FanMaster
will once again reduce the fan speed to the programmed level. ASHRAE
standard 62-1989 recommends an indoor air ventilation standard of 20
cfm per person of outdoor air or a CO
2
level which is below 1000 ppm.
Legal CO
2
limits set forth by OSHA are considerably higher and vary by
time of exposure. Rockwell Automation recommends that you seek
guidance from appropriate federal, state, and local regulating bodies for
further information.