Room Pressure Monitoring Solutions: Safe & Efficient with DwyerOmega Meta

1. What are Room Pressure and Room Status Monitors?

Differential pressure between two rooms plays a crucial role in preventing the ingress or egress of dust, particles, and pathogens from a space. Depending on the relationship between the rooms, one room will be maintained under positive or negative pressure relative to the other. This positive-negative pressure relationship is the core principle behind cleanrooms and isolation rooms. To ensure this differential pressure relationship is maintained, the use of measurement devices is imperative.

Historically, manometers and differential pressure gauges were used to monitor pressure between rooms. In some cases, verification also included monitoring airflow. As air moves from a high-pressure space to a low-pressure space, the positive/negative pressure relationship can be verified by monitoring airflow. Over time, more sophisticated building automation systems (BAS) were developed, requiring an upgrade from a simple gauge to integrated room monitoring displays with BAS controllers.

2. Room Pressure Monitors vs. Room Status Monitors

Room pressure monitors are devices that measure, display, and transmit the differential pressure between an isolation/cleanroom and an anteroom (a small room immediately outside the critical room). They communicate with the BAS system via analog outputs (4-20 mA, 0-5 V, etc.) or BACnet/Modbus® communication. The BAS system then adjusts the amount of air supplied to the cleanroom or isolation room to maintain the desired differential pressure with the anteroom.

Room pressure monitors typically only offer pressure measurement, display, and alarm features. However, they may also include door switch inputs to alert personnel when a door is left open for too long.

Room status monitors also monitor the differential pressure between anterooms and isolation/cleanrooms, but they provide additional functionality. Room status monitors not only monitor pressure but also have the capability to monitor additional room variables such as air changes per hour (ACH), relative humidity, temperature, door status, and additional room pressures.

Because room status monitors are capable of monitoring more than one differential pressure measurement, they can monitor multiple rooms simultaneously. Room status monitors accept inputs from analog or BACnet sensors to display and alarm these additional parameters.

Both room status monitors and room pressure monitors can feature audible alarms, LCD screen color changes, LED status indicators, edge light status indicators, or a combination of status lights and audible alarms to indicate room conditions.

Here's a comparison of the differences between room pressure monitors and room status monitors:

3. Where are Room Monitors Used?

Room pressure and room status monitors, sometimes collectively grouped under the term "room monitors," are both used in critical applications requiring low-pressure monitoring. Common applications include:

• Semiconductor manufacturing areas

• Pharmaceutical manufacturing and compounding areas

• Hospital isolation rooms (Airborne Infection Isolation Rooms - AIIRs)

• Cleanrooms

• Dental clinics

• School medical rooms

Indeed, with recent global events, both room pressure monitors and room status monitors have become increasingly common in healthcare facilities. The ASHE (American Society for Health Care Engineering) guidance, Health Care Facilities Ventilation Controls and Guidelines for Management of Patients with Suspected or Confirmed SArRS-CoV-2 (COVID-19), provides recommendations for airborne infection isolation rooms.

In its recommendations, ASHE states that AIIRs must be under negative pressure and meet 6-12 air changes per hour depending on building design and room criteria. Additionally, air from isolation rooms should be exhausted outdoors via HEPA filters if recirculated or to uninhabited areas outside the healthcare facility. Furthermore, ASHRAE Standard 170, Ventilation of Health Care Facilities, provides guidelines that follow CDC design requirements for airborne infection isolation rooms (AII or AIIR):

• Utilize negative pressure rooms with close monitoring of airflow direction using a pressure gauge or temporary or permanently installed visual indicators in the room when the door is closed.

Technical features of negative pressure rooms include:

• 2.5 Pa (0.01 inches of water column) differential pressure

• Minimum of 6 ACH (air changes per hour) for existing facilities, greater than or equal to 12 ACH for areas undergoing renovation or new construction.

• Air from negative pressure rooms and treatment rooms is exhausted directly outdoors if possible.

These design requirements can be met by using a room status monitor connected to peripheral sensors measuring pressure, airflow, or humidity within an airborne infection isolation room.

Finally, ASHRAE's guidance on safe school reopening provides new design requirements for educational facilities. These new design requirements apply to new and renovated buildings. They include:

• Temperature and Humidity Design Criteria

  • Winter classrooms – Maintain 72°F and 40-50% RH

  • Summer classrooms – Maintain 75°F and 50-60% RH

• Ventilation Design Criteria

  • Follow ASHRAE Standard 62.1

  • Maximize outdoor airflow

  • Disable demand-controlled ventilation

  • Use outdoor air quality sensors for outdoor pollution information.

• Design guidance for school medical rooms such as airborne infection isolation rooms (AIIRs). School medical rooms are designed to ASHRAE Standard 170 and include a room status monitor or a room pressure monitor.

4. DwyerOmega Monitoring Solutions

To meet stringent room pressure and status monitoring requirements, DwyerOmega offers a range of high-quality devices that can be integrated into various systems:

• Magnehelic® Series 2000 Gauges: Models like 2000-300MM and 2000-60PA are intuitive choices for monitoring differential pressure between rooms. They provide direct, reliable readings without the need for power.

• Digihelic® Series DHC Differential Pressure Controllers: As an effective room pressure monitor, the Series DHC is a 3-in-1 device featuring a digital display, a control relay switch, and a transmitter with both current and voltage outputs. Combining these three features reduces the number of devices needed, saving costs and installation time. Series DHC units achieve 1.5% or better accuracy at extremely low measuring ranges and 0.5% accuracy for ranges from 1 in w.c. and above.

• StabiliSENSE™ Series RSMC Critical Room Status Monitor: The Series RSMC is ideal for low differential pressure applications such as airborne infection isolation rooms. It not only monitors the differential pressure between the isolation room and the anteroom/hallway but also monitors relative humidity, airflow, and even door status.

• Series 629C Differential Pressure Transmitters: Models like 629C-05-CH-P2-E5-S1 and 629HLP-06-P2-S1 provide a 4-20 mA signal for accurate and continuous air pressure monitoring, especially suitable for complex HVAC systems in cleanrooms and isolation rooms.

• ADPS Series Differential Pressure Switches: Models like ADPS-03-2-N-C, ADPS-05-2-N-C, and ADPS-08-2-N-C provide reliable pressure control, helping to detect early issues or over-pressure conditions.

• RHP Series Humidity/Temperature Transmitters: With models such as RHP-3N44-LCD, RHPX-2SDA0-00, RHP-3D11, RHP-3S22, RHPLC-3N11, RHPLC-3N22, and RHP-3D11, these help control temperature and humidity in rooms, ensuring an ideal environment for sensitive applications.

• IEF Series Insertion Electromagnetic Flow Transmitters: Models like IEF-SN-10 and IEF-LN-10 can be used to monitor airflow velocity, a critical factor in maintaining accurate ACH in cleanrooms and isolation rooms.

• BTT Series Building Temperature Transmitters: Models like BTT-D06-1 and BTT-I06-1 can be used to monitor temperature in related applications.

• MSX Series Multi-Sense Transmitters: Models like MSX-W10-PA, MSX-W10-PA-LCD, MSX-W12-PA, MSX-W13-PA offer integrated solutions for controlling and displaying multiple critical environmental parameters.

• WFS-1001-H Flow Switch: While not directly related to room pressure, it can be used in ancillary systems such as monitoring cooling water flow for equipment in cleanrooms.

• Other products: Products such as CDT-2N40, CMT200, DEI-2288NE, GSTA-C, KTM-800-50, PFT-HAN-B611-S, RT-3000-P, SL-2000-P, T6865H2WB, TFM428KNM/U, VC6013AJC1000T, VC6013APC1000T are also part of DwyerOmega's diverse product portfolio, which can meet other specific needs in environmental management systems.

5. Preparing for Critical Space Safety – DLK is Your Partner

Regular inspection and calibration of room pressure monitoring systems are crucial to ensure safety and regulatory compliance. DLK – the official distributor of DwyerOmega in Vietnam – is ready to support you with:

• Ready stock of popular models such as 2000-60PA, 629C-05-CH-P2-E5-S1, ADPS-08-2-N-C, IEF-LN-10, RHPX-3SDA0-00, MSX-W12-PA…

• On-site technical consultation – assisting in selecting the right product for your application.

• Support for installation, calibration, and periodic maintenance.

6. Contact Technical Support

If you are looking for room pressure and room status monitoring solutions for cleanrooms, isolation rooms, or other critical environmental control systems – the engineering team at DLK is always ready to assist you.