A major source of insecurity for designers of environmental control systems for laboratory animal facilities lies in determination of metabolic heat production by the animals. This is due in part to a rather wide divergence in various recommended values found in the literature.

The purpose of this paper is to attempt to remove some of the uncertainty and insecurity surrounding selection of values of anima1 heat generation for purposes of load calculation. This attempt is based on a review and comparison of various literature recommendations, develomnent of a simple procedure for metabolic heat determination, and assessment of the effect on total system load of possible inaccuracies in the values so determined.

For calculation of the load component due to the presence of animals in the space, the development requires knowledge of the number of animals to be housed in the space and the per-unit animal(latent and sensible) heat generation and venti1at1on requirements. Each of these requirements is dependent on the animal species under consideration and each is discussed below in terms of various common laboratory animals selected to allow comparisons of data from several references.