The Construction Specifier magazine September issue arrived with an article about phase change material (PCM) ceiling panels. This was touted as an energy saving innovative solution. As described in the article ceiling panels are used to absorb daytime energy in an Arizona school with a poorly insulated roof. The PCM crystals liquify from the daytime heat. Then the panels release the energy overnight as the school cools.
Has anyone here used these materials?
To me this seems to be more about reducing peak demand when electrical energy prices for cooling will be the most expensive and allowing HVAC cooling to occur overnight when electrical prices may be less. Or it may be about slowing the solar heat transfer to the occupied spaces.
Once the heat energy is in the building, it must be rejected somehow, either by mechanical cooling or by retransmission through the poorly insulated roof. The latter will require outdoor temperatures that are low enough to create the potential to remove the daytime solar and occupant generated heat.
What are your thoughts?