Building on previous work (Choi 1993), a mixture of two n-alkanes (paraffin waxes) was developed that has a phase-change temperature between the usual supply and return temperatures of chilled-water systems. Adding such a phase-change material (PCM) to water significantly increases its volumetric thermal capacity (Lorsch 1995). Describes 1) the construction of an experimental facility and 2) experiments that evaluated the behaviour of water-PCM-surfacant mixtures under conditions encountered in building chilled-water systems. Increases in volumetric thermal capacity of such mixtures up to 20% over water were demonstrated accompanied by pressure drop increases of less than 5%. Material selection, preliminary bench tests, and instrument calibration are described in a companion paper (Lorsch et al. 1997).

KEYWORDS: year 1997, Changing physical state, materials, chilled water supply, water, mixtures, thermal capacity, fluid flow, experiment, pressure drop, measuring, heat exchangers, testing, energy storage, experiment