2020-187 Tuning Radiative Heat Flows Between Interior Surfaces and Human Occupants to Improve Heating and Cooling Efficiency

SUMMARY

UCLA researchers in the Department of Material Sciences and Engineering have developed tunable interior emissive surfaces for floors, ceilings and walls that can decrease the energy required to heat a room by 67.7% in cold weather and decrease the energy to cool a room by 38.5% in warm weather, compared to traditional interior surface materials.

BACKGROUND

Energy consumption in residential and commercial buildings contributes up to 30% of total greenhouse gas emissions worldwide. In the United States, the buildings sector accounts for 41% of primary energy consumption, of which heating and cooling are responsible for over 35%. While indoor thermal comfort is typically assumed to correlate to the air temperature of an occupant’s space, a person’s perception of comfort is subject to a range of other factors, including heat transfer between a person and the surfaces around that person. If occupant comfort could be maintained through means other than energy-consuming HVAC equipment, considerable energy savings would be possible.

INNOVATION

The reported invention introduces dynamic emissivity surfaces for interior spaces that can be tuned to improve heating and cooling of a building. By adjusting the amount of allowed long-wave infrared wavelengths, the surfaces require less energy to heat or cool a room. The surfaces have already been developed and successfully demonstrated a decrease in the required set point temperature of a room by 7°C, while maintaining occupant comfort. This corresponds to an energy savings of 67.7% in heating during cold weather and a 38.5% energy savings during warm weather. By being able to adjust a person’s environment in response to varying heat loads and conditions, these interior surfaces can maximize energy efficiency and decrease energy consumption year round.

POTENTIAL APPLICATIONS