instrumentation

Solving IAQ problems requires strategies and tools for making observations and measurements. This article covers the tools a future article will impart strategies for using them.

Data from control systems and dataloggers are useful for quantifying the performance of HVAC systems

To ensure prompt response by real-time air monitors to an accidental release of toxic aerosols in a workplace, safety professionals should understand airflow patterns. This understanding can be achieved with validated computational fluid dynamics (CFO) computer simulations, or with experimental techniques, such as measurements with smoke, neutrally buoyant markers, trace gases, or trace aerosol particles. As a supplementary technique to quantify airflows, the use of a state-of the art, three-dimensional sonic anemometer was explored.

Recommendations for the characteristics of anemometers that will ensure accurate velocity measurements are specified in the present standards. Recent research shows, however, that the requirements in the standards are based on incorrect assumptions and are insufficient to perform draught discomfort assessment that meets the accuracy requirements for human comfort specified in the indoor climate standards.

This study established a research facility where airflow velocities, temperature, and differential pressures could be measured at the ridge of an attic. Following the construction of a test building, sensors were constructed, calibrated, and installed inside the attic. Paired tests were performed for three different ridge vent treatments; two were rolled type vents and one was a baffled vent.

 Calibrating air flow measurement devices is a constant headache for users in the field. Peter Downing explains how sophisticated ultrasonics can overcome the problem.            

Microbial monitoring of the indoor environment can be performed in several ways and with the aid of different techniques. Knowing the limitations of the chosen system is of vital importance for the correct evaluation and interpretation of the results. The number of Colony Forming Units (CFU) detected by one method can not be directly compared with results from another method. The paper presents an evaluation of commonly used instruments for the collection and counting of airborne viable particles.