A review of research on PCM-based free cooling in buildings suggests that increased thermal conductivity, wider governmental support and heightened public awareness are essential to wider adoption of the technology. Among the other conclusions by a team of researchers at two universities in India:
• The free-cooling concept is best suited for less humid and maximum diurnal temperature range regions. However, with careful design of heat exchangers along with dehumidification of air, free cooling can be effectively implemented even in warm and humid areas.
• By decreasing the inlet air temperature with optimal inlet air velocity, solidification time can be reduced and thus the PCM can be charged in less time.
• Supercooling can be reduced by adding nucleating agents but cannot be mitigated completely.
• Mapping of free-cooling potential zones and construction of large-scale demonstration projects are essential to making the technology commercially viable.
• Commercializing and mass implementation of free-cooling technology in residential sectors will curtail air conditioner use and reduce greenhouse gas emissions.