Experimental and thermodynamic investigation of an ammonia/water diffusion absorption machine

•Experimental investigation of a diffusion absorption machine has been conducted.•Tests in both dynamic and steady state were achieved.•The coefficients (UA)ext and (UA)int have been determined in both states.

In this paper the results of experimental and thermodynamic investigations on a commercial absorption diffusion device are presented. Two alternative experimental methods, steady state and dynamic method, are used to evaluate the characteristics and the cooling capacity of the machine. All essential features of the machine are determined specially the overall heat transfer coefficients (UA)ext and (UA)int, respectively, 0.43 W K−1 and 0.21 W K−1. The tests are performed under practical interior ambient air conditions and variable heat loads. For a heat supply of 42 W and a generator temperature of 185 °C, a COP of 0.12 is found.