Research Laboratory Energy-Optimized Environmental Control
Space temperature, humidity, air flow plus static pressure, and fume hood face air velocity are controlled. The lab includes Variable Air Volume (VAV) supply/exhaust/return damper controls balanced for energy optimization. Supply duct air into the
lab is distributed via a full-coverage perforated ceiling: Each lab, with air-lock vestibule access, can therefore be arranged as a Clean Room (positive static pressure), Biological/Chemical/Radiological Containment (negative static pressure), or Neutral Environment (zero static pressure) without cross contamination between adjacent labs.
System Trending Chart:
Selecting This button would display a single total system continuous strip chart that will show
the values of all transmitters, actuator positions, setpoints, and
controller output signals. This is usable for tuning controller performance for the laboratory.
Controller Status & Setpoint:
Each controller is shown with a 5-state status pilot light and its current setpoint.
Transmitters & Actuators
Air Flow Metering station with transversed pitot tubes and air straightener vanes
Quick-Acting Modulating Electronic Damper Actuator with position transmitter
Humidifier Vapor Control Valve Modulating Electronic Actuator
Space Temperature Transmitter
Space Humidity Transmitter
Space Static Pressure Transmitter
Unoccupied Temperature Selector
Spill Alarm Selector
Fume Hood Sash Position Transmitter
Fume Hood Face Velocity Transmitter
BBD - Counterbalanced backdaft damper
Flow Diagram :
Sensors, Actuators and Gauges are shown within
the Laboratory control flow diagram.
The Unoccupied and Spill selectors each include a 5-state status pilot light.
Air Flow & Static Pressure Strip Chart:
This continuously monitors the Supply/Exhaust/Return CFM and space static pressure values.
It includes the air flow computed differential of Supply Air minus Exhaust and Return values.
Sequence Of Operation - Each control loop diagram is shown with its associated sensors & actuators. Each loop includes
a setpoint deviation alarm with an associated 5-state status pilot light.
Space Temperature A space temperature controller will function
to modulate the supply air VAV damper and supply air heating valve in sequence
to maintain the desired space temperature. The VAV damper position is overidden to
open further if required to maintain the space static pressure setpoint.
Space Static Pressure The lab space static pressure is referenced to an exterior area.
This controller modulates the return air damper to maintain its desired setpoint. If the return air damper
is fully close then the Supply Air VAV damper
position is further modulated open.
Fume Hood Face Velocity This controller modulates the fume hood exhaust damper to maintain the desired face air velocity, during all sash positions.Space Humidity This controller modulates the cooling dehumidification valve and the humidifier vapor control valve in sequence to maintain the desired space relative humidity setpoint.Unoccupied Selector
The Lab operator can select this locally if the lab is to be unoccupied, without a space temperature-sensitive experiment in effect.
Space temperature will then be allowed to 'float' between 65°F and 80°F, via increased controller proportional band reset, with both supply air VAV cooling and supply air heating energy minimized.
Spill Alarm Selector This local selection will function to close the lab's return air damper and open the associated spill
bypass damper to direct lab air flow into the fume hood exhaust plenum. Also, the space static pressure setpoint will
be reset to a value as required to assure a stable air evacuation from this lab.
PID Controllers: The central monitoring panel can tune each PID loop.
The Setpoint(SP), Proportional(P), Intergral(I), Derivative(D), and Controller Output(CO) values can be adjusted.