Occupancy Sensing | rickardair

Occupancy Sensing

Rickard offers further Energy Savings by shutting down diffusers when a zone is unoccupied. Built in Diffuser and Wall Thermostat Occupancy Sensing integrate directly with the standard MLM Controls. The System saves Fan Energy by closing diffusers when a zone is not occupied. Since a VAV system is pressure dependent, energy savings are realised as soon as the fan receives a signal to slow down and maintain system pressure.

  • AUTOMATICALLY SAVE FAN ENERGY BY CLOSING DIFFUSERS IN UNOCCUPIED ZONES
  • UPGRADE AS REQUIRED. OCCUPANCY SENSORS ARE MODULAR
  • ADD OCCUPANCY SENSORS BY OTHERS AS REQUIRED
  • BUILT ON RICKARD'S TRIED AND TESTED MLM SYSTEM
  • FREE SOFTWARE MANAGEMENT TOOL TO MANAGE, TUNE AND CONTROL THE DIFFUSERS
  • INTEGRATES WITH THE BMS

 

Rickard offers further Energy Savings by shutting down diffusers when a zone is unoccupied. Built in Diffuser and Wall Thermostat Occupancy Sensing integrate directly with the standard MLM Controls. The System saves Fan Energy by closing diffusers when a zone is not occupied. Since a VAV system is pressure dependent, energy savings are realised as soon as the fan receives a signal to slow down and maintain system pressure.

Rickard’s occupancy sensing can be used in applications wherever energy saving is a priority. In a typical building occupancy levels are usually in the order of 70%. By closing the diffusers in these areas, the building can save energy. Green Building innovation credits are awarded to buildings that use occupancy sensing to close diffusers when zones are unoccupied.

RICKARD MLM OCCUPANCY SENSOR LOGIC

1. Occupant leaves the room during office hours

   a. Diffuser drives to minimum control disc position
    after a preset delay (delay 1 adjustable in seconds, default is
    set to 900 seconds or 15 minutes).

   b. Diffuser drives to fully closed control disc position
    after a further preset delay (delay 2 adjustable in
    seconds, default is set to a further 900 seconds or 15 minutes). If the
    room temperature drifts outside the Work Hours Back-off band (value is
    adjustable in °C/F in the ‘Back-off band’ field), the diffuser(s) will revert
    to the minimum closed position.

2. Occupant leaves the room after hours

   a. Diffuser drives to minimum control disc position
    after a preset delay (delay 1 adjustable in seconds, default is
    set to 900 seconds or 15 minutes).

   b. Diffuser drives to fully closed control disc position
    after a further preset delay (delay 2 adjustable in
    seconds, default is set to a further 900 seconds or 15 minutes). If the
    room temperature drifts outside the After Hours Backoff band (value is
    adjustable in °C/F in the ‘After Hours Backoff band’ field), the diffuser(s)
    will revert to the minimum closed position.

3. Occupant enters the room anytime

   a. Diffuser starts to control temperature normally as
    soon as movement is detected.

4. Notes

   a. Delay 1 and 2 are the same for Working Hours and After Hours.

   b. Work and After Hours Backoff band values allow the temperature to  
    deviate above or below setpoint by the Backoff value entered before 
    driving the diffuser to minimum position.

   c. If an On-board master unit is used to control a Zone, no distinction is
    made between working hours and after hours and only the
    Backoff-band’ parameter is applicable, as the On-board master does   
    not contain a Real Time Clock (RTC).

OCCUPANCY SENSOR EXTRAS

1. Ability to Disable the Occupancy Sensor. If necessary, the occupancy
    sensor can be disabled. This can be achieved by disabling the sensor
    on the MLM application.

2. MLM Application shows occupancy sensor status i.e. Status
    (occupied/unoccupied) and a graphic indicating the period the zone has
    been un-occupied during the 1st or 2nd delay.

3. Occupancy Status variables are available to the BMS. Rickard
    Occupancy Sensors can not only  save HVAC energy by
    intelligently reacting to occupancy but can also allow Building
    Management System access for further control.

OCCUPANCY SENSOR MOUNTING POSITION

1. In the Diffuser Face Plate (Sensor Cap). By mounting the Occupancy
    Sensor in the face of the diffuser, it is unlikely that furniture will affect it’s
    coverage. Diffusers are typically mounted in the centre of a room or
    spaced symmetrically, making it an ideal position for an occupancy sensor.

Sensor Cap

2. In the Wall Thermostat face.

Wall Thermostat

 

COVERAGE

1. Rickard's onboard diffuser occupancy sensors have been specifically
    designed to sense a zone slightly bigger than a diffusers temperature
    control zone. For large open plan temperature control zones,
    multiple diffuser occupancy sensors can work together to switch that
    zone. In this case the sensor signals are combined in an ‘or’ function,
    i.e. movement picked up by any sensor will switch that zone to an
    occupied status.

2. Occupancy Sensor mounted in the Diffuser (Sensor Cap)

    a. Example Room Size 5 x 5 x 2.6m. Coverage is at least 6.2m square
        at a ceiling height of 2.6m. Coverage larger than the room size or  
        overlap of sensing zones is favourable to ensure good coverage.

3. Occupancy Sensor mounted in Wall Thermostat

    a. Best coverage is achieved by placing at 45 degrees in the corner of
        the room.

    b. Occupancy Sensor detect movement and infer that an area is 
        occupied. If there is not movement the the sensor cannot trigger.

    c. Occupancy Sensors detect movement in direct line of sight. Objects 
        that block the view of the occupancy sensor reduce it's detection of
        movement and therefore it's ability to sense movement behind that 
        object.

    d. Occupancy Sensing coverage is square pyramid in shape. Positioning
        can therefore effect performance. Position the sensor to optimize
        coverage. (See image below of coverage when the occupancy sensor
        is placed in the middle of the wall vs. positioning in teh corner of the
        room shown above.)