BA-92-01-5 -- Evaluation of Ventilation Rates Through Types of Rat Cages PDF

Laboratory animal ventilation systems should provide a healthy and pleasant environment for both animals and animal caretakers. Microenvironment (cage) conditions that animals experience may be markedly different from the macroenvironment (room) conditions experienced by their caretakers. Specifying laboratory animal ventilation rates in terms of room air exchange rates often does not guarantee even minimally acceptable environments for the laboratory animals. Quantification of the cage ventilation rates is important to understand microenvironmental conditions and is needed by laboratory animal facility designers and operators. Cage ventilation rates at four air velocities - 0, 12, 50 and 100 fpm (0. 0.06, 0.25 and 0.5 m/s), five room air flow directions - 0 deg, 45 deg, 90 deg, 135 deg, and 180 deg from the front cage surface, and four caging systems - micro-isolator, shoebox, wire-mesh multiple, and wire-mesh single - were measured using a thermal equilibrium calorimetry method. Cage ventilation rates ranged from 0.1 L/s (0.21 cfm) to 0.18 L/s (0.38 cfm) for micro-isolator, 0.6 L/s (1.3 cfm) to 1.7 L/s (3.6 cfm) for shoebox, 2 L/s (4.3 cfm) to 9 L/s (19 cfm) for double wire-mesh, and 0.9 L/s (2 cfm) to 7 L/s (15 cfm) for single wire-mesh cages.

KEYWORDS: calculating, ventilation, air change rate, animals, animal housing, laboratory animal housing, health, personnel, animals, microclimate, rooms, air, speed, air flow, measuring, air movement