Celeris® Wet Chemistry Laboratory Control Solution

The Celeris® control platform leverages the superior airflow control made possible by the Accel® II venturi valve to provide the safest, most cost effective solution for control of fume hood labs and high performance research facilities. For over twenty years Phoenix Controls has championed change in chemi​cal fume hood lab control and design to address the primary objectives of laboratory airflow control systems:  
  • Operator safety – Captures and containing fumes
  • Room pressurization – Maintains correct airflow direction
  • Ventilation – Provides proper air change rates
  • Comfort – Provides proper temperature control
  • Reliability – Provides solutions that operate reliably and require no ongoing maintenance
​​For more information on:  In addition there are many built in features that provide opportunities for substantial energy savings.
  • Switchable occupancy modes – configure ventilation and temperature set points for when the space is occupied or unoccupied and use the BMS to schedule occupancy states or control locally using a light switch and wall mounted sensor. Reduce air change rates and relax cooling and heating control at night or when the chemical fume hood lab is not occupied
  • IAQ Control – the high turndown feature of the Accel II valve allows for a significant reduction in the air change rate if the indoor air quality is measured and determined to be good. Ventilation rates may be increased if air quality deteriorates.
  • Usage Based Controls® solutions (also known as UBC® solution) – allows fume hoods to be set back to a reduced low when operators are not presents and will automatically switch to normal mode within 1 second of an operator walking up to the hood
  • Fume hood decommissioning – a unique feature of the Celeris control system where hoods that have been cleaned and will be out of service for extended time periods may have their flow reduced to virtually 0 CFM. An operator opening the sash sets the fume hood back into normal operation
  • Lab decommissioning – entire lab spaces may be set to a decommissioned state if fume hoods have been cleaned out and they will not be used for extended periods of time
The Celeris critical environmental control system offer many advanced control features that come standard in the valve mounted controllers. The Celeris system utilizes a room-level network to implement the desired control strategies and BACnet® data servers to integrate seamlessly to the BACnet capable Building Management System (BMS).

Standard Celeris room level control features include:​

  • Ventilation control – maintains the desired air change rates regardless of dynamic flow conditions in the lab space
  • Volumetric Offset control – maintains the desired polarity of the lab space relative to adjoining spaces
    • Negative – by exhausting more airflow then is being supplied
    • Positive – by supplying more airflow that is being exhausted
  • Temperature control – maintains a constant space temperature even with dynamic flow conditions caused by fume hood flow variations
    • Duct or wall mounted sensors with optional displays, set point and occupancy override features
    • Average multiple sensors per temperature zone
    • Set up multiple temperature zones per pressurized space
    • Basic cooling with reheat, discharge air reset control, BTU compensation, and Thermal Anticipatory control are all built in
  • Mode control – configure alternate flow control states that may be triggered locally or from the BMS to respond to unusual events (purge, fire, supply fan failure, exhaust fan failure, decommissioned lab)
​In addition there are many built in features that provide opportunities for substantial energy savings.
  • Switchable occupancy modes – configure ventilation and temperature set points for when the space is occupied or unoccupied and use the BMS to schedule occupancy states or control locally using a light switch and wall mounted sensor. Reduce air change rates and relax cooling and heating control at night or when the chemical fume hood lab is not occupied
  • IAQ Control – the high turndown feature of the Accel II valve allows for a significant reduction in the air change rate if the indoor air quality is measured and determined to be good. Ventilation rates may be increased if air quality deteriorates.
  • Usage Based Controls® solutions (also known as UBC® solution) – allows fume hoods to be set back to a reduced low when operators are not presents and will automatically switch to normal mode within 1 second of an operator walking up to the hood
  • Fume hood decommissioning – a unique feature of the Celeris control system where hoods that have been cleaned and will be out of service for extended time periods may have their flow reduced to virtually 0 CFM. An operator opening the sash sets the fume hood back into normal operation
  • Lab decommissioning – entire lab spaces may be set to a decommissioned state if fume hoods have been cleaned out and they will not be used for extended periods of time
Energy Saving Option Savings Simple Payback*
Indoor Air Quality (IAQ) Control $$$ < 2 years
Usage Based Controls $$$ < 2 years
Occupancy Control $$$ < 1 year
Fume Hood Decommissioning $$ < 2 years
Energy Waste Alert $ < 1 year
Shut-off Valves $ < 2 years
General Exhaust Shut-off $ < 2 years

 

$$$ = $100,000 $$ = $20,000-100,000 $ = $20,000
Based on a 100,000 CFM system

*Assumes incremental Phoenix Controls costs to achieve the energy savings.
Other equipment may be required.

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Why Phoenix Controls is the Premier Control System​

​There are a number of characteristics of the Accel II venturi valve and Celeris valve controller that make the Celeris system unsurpassed in performance for fume hood and chemical fume hood laboratory control.​
 
System Response Time: Less than One Second – Fast, stable airflow control is one of the most important factors to prevent a loss of fumes when the sash is opened. The fume hood exhaust airflow control device must respond to the change in sash opening and achieve its commanded value within one second of the sash reaching its final value. Oscillations and overshooting are not acceptable because these may result in a loss of containment.
Pressure Independence Response Time: Less than One Second – In a manifold exhaust and/or supply system with more than one VAV control device, rapid changes in volume due to fume hood sash movements will typically cause changes in duct static pressure. This action may set off oscillations throughout the entire system. The pressure independent action of the Accel II venture valve insures almost instantaneous stable airflow even when duct static pressures and volumes are varying.
Accurate Turndown Ratio (Control Range) of approximately 10 to 1 - The fume hood face velocity needs to be maintained accurately over a wide range for safety and energy-saving reasons. A typical 6 foot fume hood exhaust flow may have a 5-to-1 turndown (1000 CFM to 200 CFM). Turndown requirements for the space make up air system my approach 10, 15 or as much as 20 to 1 depending on fume hood density and ventilation and thermal demands of the space. Precise flow control over the entire turndown range is needed. An accuracy of ±5% of the desired airflow is important to maintain the correct face velocity and proper room pressurization.
Insensitivity to Inlet and Exit Conditions – Laboratories typically have large volumes of exhaust and supply airflow, which results in congested, tight ceiling areas for the corresponding ductwork. This ductwork can be quite convoluted, leaving little room for the long straight duct runs necessary to meet stated accuracies of the typical pitot tubes, orifice rings, thermal or other point specific airflow measuring devices. The unique flow metering technology of the Accel II venturi valve eliminates the need for straight duct runs upstream or downstream of the valve. Traditional flow measurement devices, such as sensors, become poor candidates for lab applications. In addition, the extra ductwork associated with these devices can significantly increase the installed cost of the system.

Traditional flow measurement devices (A) require laminar flow–adding several diameters of straight duct lengths for installation. Devices that do not have such limita¬tions (B) are desirable for tight laboratory installations. These characteristics of the Accel II venturi valve and Celeris valve mounted controller provide the proven performance required for control of fume hood lab spaces.

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The Basics of Fume Hood Control​

​Fume hood containment in your chemical fume hood lab is largely dependent on drawing a sufficient volume of air through the sash opening and establishing proper airflow patterns within the cabinet to keep hazardous or unpleasant vapors and odors from escaping the fume hood.​
  • Maintaining a consistent and proper face velocity – or airflow through the sash opening, is critical to capturing chemical fumes and exhausting them from the fume hood in both in use and vacant states.
  • Fume hood manufacturers utilize different combinations of design features such as baffles, air foils and volume of the cabinet to set up the desired airflow patterns.

Face Velocity

Fume hood face velocity is defined as the speed at which air travels through the open sash area. Common industry guidelines range from 60-120 fpm (0.3-0.6 m/s). In many modern facilities, 100 fpm (0.5 m/s) is accepted as the standard for safe operation. Research indicates that, in part, the presence and movement of an operator creates the requirement for a minimum 100 FPM face velocity. Our research also indicates that the face velocity may safely be set back to 60 fpm, regardless of sash position when no one is in front of the fume hood

There are many factors that contribute to establishing and maintaining proper face velocity. Fume hood components from Phoenix Controls have been developed and refined over the last 20 plus years and are designed exclusively for fume hood control.

  • Sash Sensing – the first element of controlling face velocity is measuring the open area of the fume hood sash. Vertical, horizontal andcombination sash sensors are available for the most basic to the most complex sash arrangements with multiple vertical and horizontal moving panes. The sash sensor signal serves as an input to the Phoenix Controls Fume Hood Monitor (FHM).
  • Fume Hood Monitors (FHMs) – the FHM takes the sash sensor signal(s), sums them and calculates the volume of air required to achieve the desired face velocity. This flow command is passed to the Celeris valve mounted controller which modulates the airflow to achieve the desired face velocity. In addition to calculating the flow command the FHM, it provides visual indications of the fume hood flow status, as well as visual and audible alarming functions.

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Four Types of Fume Hood Control​​​​​

Chemical fume hood lab airflow control has evolved as energy costs have increased and higher end controllers were developed capable of handling more sophisticated control sequences.​
  • The simplest method of controlling chemical fume hood laboratory airflow is a constant volume (CV) approach. Fume hood, supply and exhaust flows were set to a fixed flow and ran that way 24/7.
  • Two-state controls are used to gain efficiency by switching the fume hood between low flow and high flow and reducing laboratory airflow under specifi style="padding: 0 0 10px 12px;"c conditions, such as night setback. Two state control offers some energy savings over constant volume control as airflow may be reduced when the fume hood sash is lowered or the laboratory is not in use.
  • Increased energy efficiency can be gained through the Variable Air Volume approach (VAV), in which sash positioning helps determine airflow rate. As the fume hood sash opens, the airflow automatically increases to maintain a constant velocity of air through the opening. As the sash closes the airflow through the fume hood automatically decreases. The supply and general exhaust to the laboratory vary in response to changes in fume hood demand to maintain constant space pressurization. Lowering fume hood sashes in a VAV lab offers substantial energy savings as fume hood exhaust and associated may be greatly reduced.
  • Usage Based Controls from Phoenix Controls provides the greatest opportunity for energy savings. With the UBC solution, the airflow rate is automatically switched between a normal face velocity (100 fpm) when the fume hood is in use and a standby setting (60 fpm) when there is no one in front of the hood. Whether the UBC solution is used with two-state or VAV applications the supply and general exhaust to the laboratory vary in response to changes in fume hood demand to maintain constant space pressurization. Usage Based Controls, coupled with a VAV control scheme automates energy savings by reducing the flow through unoccupied fume hoods and the corresponding make up air supply by 40% even if users do not lower the fume hood sashes – without compromising safety.
The Celeris platform provides a complete control solution for chemical fume hood laboratories and integrates seamlessly to BACnet® capable Building Managements Systems.
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