Review of adsorptive heat conversion/storage in cold climate countries

The strategic goal of reducing GHG emissions opens a niche for applying an emerging technology of adsorptive heat conversion/storage (AHCS). Currently, the AHCS technologies are mainly used in countries with a hot and humid climate. However, there are many territories of the Earth with quite a cold weather. The aim of this review has been to survey the application of AHCS in cold countries. The thermodynamic indicators of AHCS cycle the first and second law efficiencies - are briefly described. For obtaining a high first law efficiency, the adsorbate exchange per cycle has to be increased, the inert masses - decreased, and a working fluid with a large latent heat should be used. The SLT efficiency for heat amplification increases at colder ambient. It opens up new possibilities for using AHCS in cold countries. The issues of which climate is deemed to be cold and how low ambient temperature can affect thermodynamic and dynamic features of the AHCS cycle/unit are considered. Traditional and recently proposed cycles/units are surveyed, and their applicability for cold territories is analyzed for closed and open AHCS systems. Special attention is paid on two new approaches intently proposed for cold climates, namely, a "Heat from Cold" cycle for upgrading the ambient heat temperature and a Ventireg process for regeneration of heat and moisture in ventilation systems. The performed analysis shows the prospects of AHCS technologies for cold countries and outlines the boundaries of their applicability.