This is a concept to use a material like salt which responds slowly to changes of temperature, to provide a house with the summer’s heat in the winter, and winter’s cooling in the summer. 

Shown is a horizontal heat sink (salt, concrete, etc.) which is insulated from the weather except for an exposed end at a distance from the house.  The opposite end of the heat sink is exposed inside the house to radiate the temperature it was exposed to six months earlier.  Thermally, the heat sink is 6-months long.  

Alternately, the roof of a house can be made of a material, the thickness of which would be chosen to have a one-day cycle to insulate the house during the day, and to radiate the day’s accumulated heat inside the house at night.  In theory, the thickness could be increased to have a 6-month lag. From that time on, the house receives essentially free heating and air conditioning.  

https://www.hineslab.com/thermal-lag-heating