Erfarenheter av kontrollerad miljö i försöksdjurslokaler

Abstract

It is important for many animal model studies, particularly with rodents, to be performed in a well standardized and controlled physical environment. Otherwise the observations and measurements done might create difficulties in interpretation, or the results might even be impossible to reproduce or verify in another laboratory.
In the animal department of BISAM at Umea university the ventilation system was modernized in 1983-84 in the rodent facilities, with supply of air through new devices in the ceiling and exhaust of air through perforated walls on two sides of the rooms. The supply air comes from a climat chamber where the incoming air should be properly heated and humidified, as controlled by thermo- and hygrostats in the chamber outlet. The animal rooms are also equipped with a sprinkler system for additional humidification as necessary.
This report presents results on controls made on temperature and humidity stability in these rebuilt rodent facilities during summer (1984) as well as winter (early 1985) conditions. The capacity of the air supply system was also controlled.
In summary, the temperature in the animal rooms tended to be high during summer, and increased in periods of high out of door temperature so that in the animal cages the temperature could exceed 31 °C. The relative humidity was above accepted levels most of the time. On the other hand, during winter it seemed to be possible to keep the temperature within the desired levels, but the relative humidity was unacceptably low.
With these results at hand, the air supply system was controlled for its ability mainly to humidify the air. This control was done during autumn and showed that at that time of the year the capacity was just at limit to give the desired humidity in the animal rooms. The main >>function<< of the room sprinkler system was in fact to decrease room temperature and to give unstable temperature and humidity. During winter when very cold, dry air should be heated and humidified the capacity of the climat chamber is far from sufficient. The high temperature in the rooms during summer depend upon the lack of cooling possibilities in the chamber.