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AireLogic units that recirculate air after the burner are physically constrained to limit the
percentage of return air. These constraints are meant to provide the proper dilution air.
These units
are not listed
by an independent third party testing agency and do not use the
equivalent temperature rise control scheme to limit burner modulation.
In order of lowest to greatest priority the burner modulation parameters are: room
temperature, discharge or supply air temperature, and equivalent temperature rise.
There are three Energy Savings modes that could disable the burner.
Energy Savings Mode 1
Mixing Box Recirculating Units
Energy Savings Mode 1 will automatically disable the burner if the mixed air temperature
is equal to or greater than the minimum discharge air temperature setpoint, and the room
air temperature is 5°F above the room air temperature setpoint. This function is intended
to restrain the room temperature from rising uncontrollably in buildings with internal heat
gain. In certain conditions it may be necessary to readjust the minimum discharge air or
room temperature setpoint upward or adjust the outside/return air ratio to provide a
warmer supply air temperature.
Energy Savings Mode 1
Non-Recirculating Units
Energy Savings Mode 1 will automatically disable the burner if the outside air
temperature is equal to or greater than the minimum discharge air temperature setpoint,
and the room air temperature is 5°F above the room air temperature setpoint. This
function is intended to restrain the room temperature from rising uncontrollably in
buildings with internal heat gain. In certain conditions it may be necessary to readjust the
minimum discharge air or room temperature setpoint upward to provide a warmer supply
air temperature.
Energy Savings Mode 2
Mixing Box Recirculating Direct-Fired Units
Energy Savings Mode 2 will automatically disable the burner if the burner’s minimum
firing rate exceeds the allowable equivalent temperature rise. This condition is unlikely to
occur unless the burner’s minimum firing rate is misadjusted and set too high, or the inlet
air opening is restricted.
Energy Savings Mode 3
Energy Savings Mode 3 will automatically disable the burner if the outside air
temperature is above the Heating Economizer setpoint. This function is similar to an inlet
duct thermostat. The burner will cycle back on if the supply air temperature drops 3°F
below the Heating Economizer setpoint.
To change the desired heating economizer temperature scroll through the SETPOINTS
menu tree, locate the HEATING ECONOMIZER Setpoint, and enter a new temperature.
The default for this setpoint is 65°F. The allowable temperature range is 40°F - 130°F.
Ventilation Mode
Ventilation Mode occurs when the fan is running but the unit is not providing heating or
cooling.
The ventilation mode is dependent on the room (MRT and MRT-Expert) or outside air
(MDT and MDT-Expert) temperature. The heating/ventilation/cooling operation is
