Keeping your world up and running.®

The need for high quality building environments

By Ron Auvil

February 2012

Fluke 975 AirMeter™

This technician is using the Fluke 975 AirMeter™ to check the temperature, humidity, and CO2 levels in an operating room.

In general, a quality building environment is one in which the following conditions are accurately measured and controlled: temperature, humidity, pressure, and indoor air quality. Light level and other measurements may be needed as well. While many facilities need these conditions to be good, high quality applications have an important or even critical need.

Some examples of applications that require a high quality building environment approach include hospital operating rooms, pharmaceutical manufacturing facilities, computer server rooms, precision component manufacturing facilities, specialized product storage/warehouse areas, and electronics assembly areas.

Impact of high quality building environments

A number of factors drive the need for high quality building environments. Among the most important are the requirements imposed by regulatory agencies such as The Joint Commission (formerly JCAHO) for hospitals and the Food and Drug Administration (FDA) for the pharmaceutical industry. Some facilities are not permitted to function or to release a product if they do not meet high quality building environment conditions. In addition to the regulatory agency requirements, other factors such as legal risk, market conditions, and the expense of system downtime and failure are all of critical importance.

Failure to maintain a high quality building environment can result in fines, lawsuits to recover damages, and product recalls.

Measurements of high quality building environments

Here is why sensing is important, and here’s the reasoning behind what has been deemed “proper” or necessary. Measurement devices include those permanently mounted as well as portable handheld instruments used for spot-checking and for calibration of the permanent units.

Hospital operating rooms

The environment of an operating room is driven by the practical needs of the patients, doctors, nurses, and medical equipment. Research shows a link between the operating room environment and surgical outcomes. An operating room must have the proper light level to perform medical procedures. The doctors and nurses are heavily garbed to prevent infection. The lights and medical machines require cooling. Lower temperatures reduce bacteria growth. Operating rooms require close-tolerance humidity control. Usually each operating room has its own humidifier to add humidity as needed. Doctors and other staff often want to be able to change the temperature and humidity in the operating room drastically. They also want the environmental system to respond very quickly. In addition to temperature and humidity, room pressure is also controlled. A slightly positive room pressure is needed to reduce the possibility of contaminants coming into the operating room. With infectious diseases, a negative room pressure reduces the spread of the disease to areas outside the room. It is not easy to achieve all of these requirements at one time; it is also quite expensive.

Typical operating room mechanical and control system

The typical operating room mechanical system consists of a variable air volume (VAV) box that controls the amount of inlet air in response to the temperature control loop. An air handling unit (AHU) supplies air to the inlet of the VAV box at 55 degrees F (13 degrees C) at 1 inch (2.5 centimeters) WC static pressure. While a typical VAV box will control the airflow in response to the temperature control loop, some of these boxes are actually used as constant volume systems and the cubic feet per minute (CFM) values are locked in and do not change. Usually this indicates that there have been previous airflow problems. The VAV box will include a hot water or possibly an electric reheat coil as well as a humidifier. In most operating room systems the inlet VAV box is accompanied by an outlet or return air VAV box. The outlet VAV box controls the CFM of air being drawn through the return duct. The reason there are two VAV boxes is operating room (OR) pressure control. If more CFM of air enters the room than leaves the room, the room will have a positive pressure. If more air leaves the room than enters the room, the room will be under a negative pressure. Depending on the procedure, either may be applicable.

Sensors

An operating room application needs a number of sensors that are accurate, calibrated, and functional. These include the following:

  • Space temperature
  • Space humidity
  • Inlet velocity pressure for the inlet VAV box supply loop
  • Inlet velocity pressure for the outlet VAV box supply loop
  • Discharge air temperature
  • Room differential pressure

Proper operating room functioning is critical to the success of the health care provided. Operating rooms are checked for proper operation by agencies such as The Joint Commission, which establishes many standards for the health care industry.

These sensors are almost always wired to a building automation system (BAS). These sensors are used for control, alarming, data trending, and reporting. The sensors must be checked for accuracy using a high quality certified instrument. The Fluke 975 AirMeter™ is perfect for this application. It is able to measure temperature, humidity, CO2, CO, and air velocity in the duct. The readings can be stored in the meter and then sent to a laptop computer using FlukeView® Forms Documenting Software. This makes it easy to have the values available for reports to The Joint Commission.

When checking the accuracy of the sensors, compare the 975 AirMeter™ reading to the indicated reading at the building automation system HCI (human computer interface). Commonly, some sensors have their own built-in displays. If the sensor readings are significantly different from those at the calibrated 975 AirMeter™, the sensors may be recalibrated or replaced as well. Note that BAS software also allows sensor calibration and scaling, which must be taken into consideration.

Pharmaceutical manufacturing facilities

The manufacturing - and storage - of pharmaceutical products demands a high quality building environment. The safety of the public demands these products adhere to the strictest standards. The mechanical systems and control system must be designed with this in mind. Data that indicates the conditions in the space is stored on a computer server and maintained for inspection by the US Food and Drug Administration(FDA). Strict record-keeping rules are mandated by the FDA.

Sensors

A pharmaceutical manufacturing application needs a number of sensors that are accurate, calibrated, and functional. These include the following:

  • Space temperature
  • Space humidity
  • Discharge air temperature
  • Room differential pressure
  • Particle count

The Fluke 975 AirMeter™ can be used in this application. You can use a high quality particle counter, such as the Fluke 983, to measure the size and number of the particles in the air and ensure the number meets the appropriate standard.

Fluke 983

The white piece of plastic in his hand is a filter that’s used to essentially confirm the calibration of the particle counter. Then he can use the Fluke 983 Particle Counter to check the particulate levels in settings such as a hospital operating room.

Computer server rooms

The nervous system of a facility today is the computer network. The nerve center of the computer network is the server room. Here are racks of computer servers that provide data and functionality for almost every function in the building. The servers generate large amounts of heat, so constant cooling is a must. Humidity is also critical to reduce static discharges. If the servers are down even for a short period of time critical building functions will stop. Downtime may run into thousands of dollars per minute.

Sensors

A computer server room application needs a number of sensors that are accurate, calibrated, and functional. These include the following:

  • Space temperature
  • Discharge air temperature
  • Space humidity

Space humidity sensing and control is especially important to reduce static electricity in the server room. Static electricity may cause electrostatic discharge (ESD), which can damage or cause improper operation of electronic equipment.

You can use the Fluke 975 AirMeter™ in this application, as well as the Fluke 983 Particle Counter to measure the size and number of the particles in the air and ensure the number meets the appropriate standard.

Precision component production facilities

The production of precision components requires a high quality building environment. If components are manufactured in the wrong environmental conditions, they may be out of tolerance or corrosion may result. This can cost thousands of dollars in damaged and lost product. A high quality environment will include temperature and humidity control.

Sensors

As with the locations already listed, a manufacturing facility application needs sensors that are accurate, calibrated, and functional. These include the following:

  • Space temperature
  • Space humidity

Space humidity is very important because metal surfaces may rust or corrode with high humidity levels in the air.

For this application you can use the Fluke 975 AirMeter™ as well as a high quality Fluke 983 Particle Counter to measure the size and number of the particles in the air and ensure the number meets the appropriate standard.

Specialized product storage/warehouse areas

After products have been produced they must be stored. For many products storage in the proper high quality environment is crucial. For example, foodstuffs will ripen or deteriorate quickly in the wrong environment. Paper will be useless for feeding into high-speed presses if stored under improper humidity conditions. For many products, filtering is critical to keep contaminants from destroying them.

Sensors

A product storage/warehouse area application needs a number of sensors that are accurate, calibrated, and functional. These include the following:

  • Space temperature
  • Space humidity
  • HVAC system discharge air temperature

Once more you can use the Fluke 975 AirMeter™ to check the accuracy of the temperature and humidity sensors.

Electronics assembly areas

Almost every area of our lives is touched by electronic components. These components are assembled under very tight filtration, temperature, and humidity conditions. Clean rooms ensure that very few particles are able to contaminate the components, possibly damaging or destroying them. These clean rooms are rated by the number of particles of a specific size that are present in a cubic meter of air. The filtering demands of these rooms are very high.

Sensors

As with the other applications, an electronics assembly area application needs a number of sensors that are accurate, calibrated, and functional. These include the following:

  • Space temperature
  • Space humidity
  • HVAC system discharge air temperature
  • Particle count

You need a particle counter to measure the number and size of particles in the air. The particles may damage the sensitive electronics under manufacture.

As with the previous applications, you can use the Fluke 975 AirMeter™ to check the temperature and humidity sensors as well as the Fluke 983 Particle Counter for measuring size and number of the particles in the air.

High quality building environment best practices

Successful facilities follow a number of best practices in the creation and use of high quality building environments. Some of these are:

  1. Use of a design engineering firm that is familiar with the design and operation of a building environment similar to the type being considered
  2. Participation of building staff in the design and layout of the facility or area
  3. Use of high quality sensors, test equipment, and control devices
  4. Rigorous verification and documentation standards, even perhaps above and beyond those demanded by the governing agencies
  5. Staff training and development program to ensure that proper procedures are followed and equipment is maintained properly

Conclusion

A high quality building environment is no accident. It starts with a well-designed area and then a mechanical system to serve it. It is amazing to see people take existing HVAC systems and attempt to use them for a high quality area. The result is at best a disappointment. The system needs to be designed specifically for the application and not simply an extension of the ductwork of an old system. Proper sensing and control of the environment must be added as well. After all this, the high quality building environment must be started up and the space verified by a commissioning agent. Then the building maintenance staff should be trained in the proper maintenance and operation of the mechanical system as well as the techniques of using the measuring devices.

An Operating Room Retrofit

Traditionally, operating rooms (ORs) are one of the toughest applications in the HVAC/Controls industry. Recently a client called and asked me if we could put together a package of improvements for two of their operating rooms. These ORs had last been thoroughly commissioned and upgraded about 10 years prior, so they were really due.

As part of the commissioning and upgrade the customer requested:

  1. Verify programming and operation of existing DDC controllers on VAV boxes.
  2. Verify airflow readings and set points.
  3. Replace old temperature and humidity sensors with new, NIST-certified models. These sensors must have a local LCD readout so that hospital staff can monitor conditions directly in the room. Sensors must also have adjustable temperature and humidity set points. This will allow staff to change the room conditions without having to call building staff.
  4. Verify operation of new humidity sensors and humidifier system.
  5. Check room pressure to make sure it is positive.
  6. Make sure existing DDC programming on head end for set points, trends, and alarms works properly.