Systems and methods for tuning radiative heat flows between interior surfaces and human occupants

A device comprising:

• an interior space;
• an interior surface disposed within the interior space configured for absorption and reflection of a long-wave infrared heat from a long-wave infrared heat source and oriented to reflect the long-wave infrared heat;
• wherein the interior surface comprises:
• an at least one tunable emissivity material;
• an at least one power source;
• and
• at least two electrodes;
• wherein the at least one tunable emissivity material is disposed between the at least two electrodes;
• wherein the at least one power source is electrically coupled to the at least one power source and the at least one tunable emissivity material and the at least one power source is configured to apply a voltage to the at least one emissivity material;
• wherein the at least one tunable emissivity material is configured with at least a low emissivity state and a high emissivity state;
• wherein the low emissivity state has an emissivity value smaller than about 0.5 over wavelength range from about 7 microns to about 14 microns and the high emissivity state has an emissivity value larger than about 0.8 over wavelength range from about 7 microns to about 14 microns for long-wave infrared wavelengths;
• wherein the low emissivity state has low absorption and high reflection of long-wave infrared heat and the high emissivity state has high absorption and low reflection of long-wave infrared heat;
• wherein tuning the at least one tunable emissivity material comprises applying the voltage to the at least one tunable emissivity material to change the emissivity state of the at least one tunable emissivity material to regulate radiative heat flow between the interior surface and a location;
• and
• wherein the interior surface is configured for a set point temperature such that when a target temperature exceeds the set point temperature the voltage is applied to at least one tunable emissivity material to change to an emissivity state with an emissivity value larger than about 0.8 to maintain thermal comfort at the location and when the target temperature falls below the set point temperature the voltage is applied to at least one tunable emissivity material to change to an emissivity state with an emissivity value smaller than about 0.5 to maintain thermal comfort at the location.