Combined with the phase change material, this would allow a boiler to fire much less often -- seems like a great idea, if you ask us.

ENGADGET

Beyond this eco-friendly element, Radiator Labs is integrating a phase change material into its product that can store energy and heat an apartment for up to four hours without assistance from the boiler.

ENGADGET

The Embrace bag contains a pouch filled with a phase-change material that melts when heated and maintains a consistent 37 degrees Celsius as as the wax hardens over the next four to six hours.

FORBES: The Sleeping Bag That Will Save Thousands of Babies