12
o
External zones considered of primary importance should have both their heating and cooling
weight set to 100%
o
Zones considered of secondary importance can have their weight set to a lesser value than 100%
to reflect their importance on the systems total voting when making demand calculations.
o
Due to, their location, exposure, design, etc……, certain zones can have problematic behaviour
specifically in peak heating or cooling mode. (Ex.: when an office surrounded by panoramic
windows).
These zones can have their peak load demand satisfied. However this will be either at the expense
of energy used and or slightly overheating or overcooling the other zones.
It is the responsibility of the installer to properly identify any problematic areas and to determine if
those problematic areas are to be either fully satisfied or to simply leave them unsatisfied during
certain peak load periods in order to minimize energy consumption and to allow the rest of the
zones in the system to be optimized.
When dealing with the type of system which control many areas from a single central system, a
choice must be taken during set-up to either prioritize comfort or equipment cycling and energy
consumption.
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Adding many master voting zones (including problematic ones) to an RTU thermostat will
provide better comfort at the expense of higher energy consumption.
-
Restricting the number of master voting zones (and excluding the problematic ones) to the
RTU thermostat will always provide a more energy efficient system at the expense of
comfort in certain areas.
2E) Minimum, Maximum and Heat flow Adjustments
Although system balancing can be accomplished by utilizing the thermostat’s built in configuration settings.
It is recommended to add a balancing side-takeoff damper on all zones. This will ensure that any
supplementary air can be reduced and will limit excessive noise due to airflow if the zones or associated
ductwork were improperly sized.
Minimum Position Adjustment (Min Pos)
This parameter sets the minimum amount of air being delivered to the zone. The VAV damper (when
powered) will never close below this value setting.
Maximum Position Adjustment (Max Pos)
This parameter sets the maximum amount of air being delivered to the zone; both in heating and cooling
mode. The VAV damper (when powered) will never open above this value setting.
Please note that the maximum amount of hot air delivered is set by this parameter, and NOT the Max Heat
flow parameter. Please refer to the next section for a description and usage of the Max Heat flow
parameter functions.
