HLS34 fan coil unit controllers are suitable
for wide range of fan coil unit applications including 2-pipe and 4-pipe
FCUs with automatic demand based fan speed control, and for air-side control
applications. HLS34 controllers have unique capability of boosting the
fan speed based on the room space air quality (CO2 measurement). This
is particularly effective feature when the FCUs are connected to fresh
air duct work or are mounted on the outside wall with fresh air inlet.
Controllers can also be configured for VAV control with CO2 fresh air
control.
The HLS34 controllers have very easy to understand LCD display and unique
MagicTouch™ buttons for user settings. HLS34-S1 allows the users
to adjust the room setpoint by pressing + and - buttons and to provide
day extension. HLS34-S2 has additional fan speed control override button.
The user setpoint adjustment range is limited at the commissioning to
a range, typically +/-3 degrees. When the HLS34 controller goes into night
mode (reduced setpoint) and returns back to day mode, it has an option
to reset the user adjustment offering key energy saving features.
The HLS34 is controlled between day and reduced night setpoints via a
local hard-wired presence switch such as PIR, or over the network from
the central interface. When in the night mode the controller can be overriden
to the day mode by the user for a specified time by pressing the Day Extension
button.
The HLS34 controller controls the temperature to the required setpoint
by modulating the heating and/or cooling valves. The controller has capability
of using thermic, 3-point and 0-10Vdc fully modulating actuators making
accurate control possible.
The HLS34-S3 model has been designed for air-side control applications,
where the control valve output is required to be at 50% position when
at the setpoint. The air-side control applications use a damper to divert
the air flow through a heating coil or cooling coil, and are widely used
in the UK.
The diagram below illustrates the temperature control logic for the 2-pipe
and 4-pipe fan coil unit applications.. |
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