When Heat is called for in the night time, or sunless hrs, or Winter season, humidified air flows through the zeolite. As the humidity is adsorbed with the zeolite, heat is released for the air and subsequently for the making Area. This type of TES, with precise utilization of zeolites, https://www.gledhill.net/products/thermal-storage/boilermate-ov-pre-plumbed/