In this paper, a two modular zeolite water adsorption heat pump (AHP) based on the
thermal wave concept has been experimentally investigated. Each module composes of two
heat exchangers contained in a hermetic stainless steel vessel. The first heat exchanger
is the adsorber/desorber located on the top of the vessel, while the second is the
evaporator/condenser heat exchanger located on the bottom of the vessel. Throughout this
work, the effect of the non-dimensional switching frequency, which has been introduced and
theoretically investigated by Alam et al. [Int. J. Heat Mass Transfer 43 (2000)
4419–4431], on COP and the mean heating power of an adsorption heat pump has been
experimentally investigated under one typical working condition of AHPs. The results
showed that the switching frequency and adsorber/desorber flow rate have strong influences
on both COP and the mean heating power. It has been also found that there is an optimum
switching frequency corresponding to each flow rate, at which the COP attains its maximum
value. The obtained optimum switching frequencies vary slightly from 0.28 at an adsorber
fluid flow rate of 0.6 l.min-1 to 0.32 at 1 l.min-1.