Page IV - 70 
Ventilation Design Handbook on Animal Research Facilities Using Static Microisolators 
4. 1 .3. 1 .2 Empty Room: Test Procedure 
The room air temperature was operated at 22.0 °C (71.6 °F) with a plus or minus tolerance of 
1.5 °C (2.7 °F) throughout the room. Difference between the supply air temperature and the 
mean of the room surface temperatures was less than 1.5 °C (2.7 °F). The room surfaces were 
insulated and both the interior and exterior of the room were maintained at the same temperature. 
All surface temperatures were measured with an infrared thermographer (Cole-Parmer 
Instrument Co. model 39650-12). Surface temperatures were recorded at the beginning and end 
of each batch of data (approximately four hours). Measurements were taken at the center of each 
wall and the floor, and on the four sides of the ceiling halfway between the diffuser and the 
walls. These temperature measurements are tabulated in appendix I: section 4.3.1. 
The room was operated at a slight positive pressure (at lOpa (0.04” of H 2 O column) to eliminate 
incoming air currents other than the diffuser. The supply airflow rate was controlled at a constant 
value of 128 cfm (6.0e-2 mVs), that was 10 air changes per hour (ACH) for the testing room. The 
exhaust airflow rate was maintained at 102±2 cfm (appendix I: section 4.3.1). 
Air volume flow rates into the room diffuser and out of the exhaust grill were measured with 
precision nozzles machined according to specifications given in the ANSI/ASHRAE Standard 
51-1985. The nozzles were located in the ducts outside of the room. Airflows were controlled 
and measured continuously during each experimental run by measuring the pressure drop across 
the nozzles with a manometer. Duct fans were placed downstream of each nozzle. The supply 
fan was adjusted to provide the required airflow into the room and the exhaust fan was adjusted 
to provide the required static pressure in the room. 
Three zones were used for data collection. The entire room airspace was zone 1. The air space 
0.30m (L) from the diffuser surface was zone 2. The air space 0.30m (L) from the exhaust outlet 
was zone 3 (figure 4.45). The total number of measurement locations is shown in table 4.1.13. 
Temperature, air velocity, and turbulence intensity were measured every 5.1e-2m (2”) within 
0.30m (12”) of the diffuser and exhaust, and every 0.15m (6”) throughout the rest of the room. 
Temperature was measured with type-T thermocouples. The temperature sensors were calibrated 
in a temperature controlled water bath that was set according to a SAMA thermometer. The air 
velocity and turbulence intensity levels were measured with sensors that were designed and 
constructed at the Bioenvironmental Engineering Research Laboratory (BERL) at the UIUC. 
This air velocity sensor has a thermistor sensing head that is maintained at a constant 
temperature and is described in Li (1994). The accuracy is plus or minus 3 percent of reading or 
plus or minus 2 fpm, whichever is greater. The air velocity sensors were calibrated prior to the 
experiment in a TSI Certified Air Velocity Calibrator (model 8390). The air velocity sensor is 
omni-directional and has a fast response time so it can measure turbulence intensity as well as air 
velocity. Outputs from the temperature and air velocity sensors were collected on a data 
acquisition system (DAS-8 with EXP- 16 expansion boards, Keithley-Metrabyte, Inc.) and an 
IBM compatible computer. 
