Thermal Mass
In general, thermal mass refers to heat storing materials. This type of integration into your heating and cooling system has the potential to greatly reduce the needed amounts of active heating and cooling, as well as the consumption of fossil fuels and non-renewable resources. As with any type of passive heating and cooling system, when integrating the use of thermal mass into your structure, in order to get the most use out of the system, make sure that it is a part of a much larger overall system. Although, some features to help reduce the need for active heating and cooling is much better than nothing at all!! The type of thermal mass that will be best for you will greatly depend on your climate, so make sure you research the needs for your specific environment.