Variable Air Volume (VAV) control solutions offer tailored air management for different laboratory environments, improving both energy efficiency and safety.
Here is an overview of different lab designs and the appropriate solutions:
| Lab Design | Entry/Exit Door Status | Lab Room Controller | Fume Hood Controller |
|---|---|---|---|
| Fume hood alcove | None | Laboratory Room Controller | Fume Hood Controller |
| Open | None | Laboratory Room Controller | Fume Hood Controller |
| Enclosed | Open upon entry/exit only | Laboratory Room Controller | Fume Hood Controller |
| Teaching | Open for extended periods of time | Laboratory Room Controller | Fume Hood Controller |
| High containment | Open upon entry/exit only | SureFlow Room Pressure Controller | Fume Hood Controller |
1. Fume Hood Alcove Labs
Fume Hood Alcove Labs are designed with an open layout and a high density of fume hoods, snorkels, and biosafety cabinets that provide primary containment. In these labs, a negative air balance ensures secondary containment, while minimum fume hood exhaust is sufficient for basic ventilation. The room controller in such labs plays a crucial role in simultaneously managing room balance, ventilation, and temperature. It continuously measures supply and exhaust volumes, ensuring a constant flow offset to maintain appropriate airflow. If the offset becomes too large, the controller opens the supply, and if it becomes too small, it adjusts the system to maintain the negative balance necessary for safety. By utilizing VAV (Variable Air Volume) control, airflow is reduced when possible, leading to significant energy savings. Low-pressure drop dampers, recommended by the US EPA, further reduce fan energy. These systems provide best-in-class accuracy for flow measurements, while closed-loop control of fume hood face velocity ensures user safety.
- Characteristics: Open lab space with a high density of fume hoods, snorkels, and biosafety cabinets. Negative air balance is used to maintain secondary containment.
- Operation: The room controller adjusts airflow to maintain lab balance, ventilation, and temperature. It measures supply and exhaust volumes to ensure a constant flow offset.
- Energy Savings: VAV controls reduce airflow, saving energy, while low-pressure drop dampers reduce fan energy.
2. Open Labs
Open Labs are laboratories without physical barriers, open to surrounding areas, and often require careful control of airflow to maintain a safe environment. Fume hoods, snorkels, and biosafety cabinets provide primary containment, while a negative air balance ensures secondary containment. General exhaust is typically required to maintain minimum ventilation (air changes per hour or ACH). The room controller in open labs manages the room balance, ventilation, and temperature, measuring supply and exhaust volumes to maintain consistent airflow. If the room balance becomes too negative, the general exhaust is reduced, and the supply air is increased to its maximum setpoint. Conversely, if the room balance is insufficient, the supply air is reduced, and the exhaust increases. This dynamic control allows the VAV system to efficiently adjust airflows, reducing energy consumption by minimizing unnecessary ventilation. In addition, low-pressure drop dampers help lower fan energy.
- Characteristics: Labs open to surrounding areas with a need for primary containment via fume hoods and general exhaust for ventilation.
- Operation: The room controller manages air volume, exhaust flow, and temperature. General exhaust is used to maintain minimum ventilation.
- Energy Savings: Reduces airflow and uses low-pressure drop dampers to minimize fan energy consumption.
3. Enclosed Labs
Enclosed Labs are typically sealed rooms where the door remains closed to maintain a controlled environment. These labs use VAV controls to reduce airflow and save energy while maintaining negative room pressure differentials for secondary containment. Fume hoods and other containment equipment provide the primary safety barrier, while the room controller manages room balance and temperature. The controller continuously monitors the pressure differential between the supply and exhaust air, adjusting the system as needed to maintain containment. If the room pressure becomes too negative, the general exhaust is reduced, and the supply is increased. If the pressure is not negative enough, the offset increases to restore balance. This precise control ensures that the room pressure is tightly regulated, enhancing safety for high-risk activities. VAV control reduces the need for excess airflow, while low-pressure drop dampers lower energy costs by minimizing the pressure drop in the system.
- Characteristics: Labs with closed doors, where VAV controls ensure negative pressure differentials and maintain secondary containment.
- Operation: The room controller maintains airflow balance and measures room pressure differentials to keep containment tight. If needed, airflow adjustments ensure both temperature and ventilation setpoints are met.
- Energy Savings: VAV control reduces airflow, and low-pressure drop dampers allow smaller HVAC components.
4. Teaching Labs
Teaching Labs are enclosed spaces that often have doors open frequently, which adds complexity to airflow management. These labs require VAV controls to reduce airflow and save energy, with fume hoods and other equipment providing primary containment. A negative air balance is used for secondary containment. The room controller in teaching labs measures supply and exhaust volumes to maintain a constant flow offset, ensuring the room balance remains within safe limits. If the room becomes too negatively pressurized, the general exhaust is reduced, and the supply air is increased. Conversely, if the room pressure is insufficient, the supply air is reduced, and the general exhaust is increased. The room controller also manages temperature by opening or closing heating valves as needed. This continuous adjustment ensures both occupant comfort and experiment integrity. VAV control reduces unnecessary airflow, leading to energy savings, while low-pressure drop dampers contribute to efficient system performance.
- Characteristics: Similar to enclosed labs, with open doors being common. Fume hoods and negative air balance provide containment.
- Operation: Room controllers manage airflow to maintain lab balance and control fume hood exhaust. This setup ensures stable ventilation and temperature management.
- Energy Savings: Efficient VAV control and low-pressure dampers lead to energy savings and system optimization.
5. High Containment Labs
High Containment Labs are designed for handling hazardous materials and require strict control of room pressure differentials to ensure containment. These labs use VAV controls to minimize airflow when possible, reducing energy usage while maintaining safety. The room controller plays a vital role by continuously monitoring and adjusting the room pressure differential. If the pressure becomes too positive or not negative enough, the controller reduces supply airflow and increases the exhaust to restore containment. Conversely, if the room becomes too negatively pressurized, the supply air is increased, and the exhaust is reduced. When a door is opened, the system holds directional airflow to maintain containment. The room controller also manages temperature by adjusting airflow and heating valves to meet setpoints. By providing best-in-class flow measurement accuracy and tight control of room pressure, these VAV systems ensure the highest levels of safety in high-hazard environments, while reducing energy costs with low-pressure drop dampers and minimized airflow requirements.
- Characteristics: Labs that are tightly controlled for hazardous materials, with strict room pressure differentials.
- Operation: Direct pressure control ensures precise containment. VAV systems dynamically manage airflow and temperature while maintaining pressure during door switches or mode transitions.
- Energy & Cost Savings: Reduced airflow and low-pressure dampers save energy, while optimized system design minimizes installation and operating costs.