Climate changes and urban sprawl dramatically increase the urban temperatures and the thermal quality in the built environment. Among several proposed mitigation techniques, cool roofs have now reached a broad audience, while the cool materials potentialities for façade applications are still little investigated. A novel masonry paint, produced with the inclusion of cool pigments, is investigated in this paper. A palette of colour is developed with the objective of covering a wide range of architectural integration solutions. Reflectance and emissivity are measured and calculated. The results strongly depend on the base colour used to prepare the sample; solar reflectance increase up to 0.16 is achieved for dark colours. A numerical analysis is carried out to evaluate the impact of the cool paint on the thermal response of a typical Italian residential building. Energy uses are calculated for different insulation levels and climatic conditions. Cooling energy uses are reduced in the 10-20% range; total energy uses are affected by several parameters with 5% maximum savings. Peak operative temperature reductions range from 0.5 to 1.6 °C for the building in free floating conditions, according to climate and insulation level. External surface temperatures are reduced above 6 °C during the peak irradiation hours. © 2015 Elsevier B.V. All rights reserved.
Characterisation and assessment of near infrared reflective paintings for building facade applications
Zinzi, M.
2016-01-01
Abstract
Climate changes and urban sprawl dramatically increase the urban temperatures and the thermal quality in the built environment. Among several proposed mitigation techniques, cool roofs have now reached a broad audience, while the cool materials potentialities for façade applications are still little investigated. A novel masonry paint, produced with the inclusion of cool pigments, is investigated in this paper. A palette of colour is developed with the objective of covering a wide range of architectural integration solutions. Reflectance and emissivity are measured and calculated. The results strongly depend on the base colour used to prepare the sample; solar reflectance increase up to 0.16 is achieved for dark colours. A numerical analysis is carried out to evaluate the impact of the cool paint on the thermal response of a typical Italian residential building. Energy uses are calculated for different insulation levels and climatic conditions. Cooling energy uses are reduced in the 10-20% range; total energy uses are affected by several parameters with 5% maximum savings. Peak operative temperature reductions range from 0.5 to 1.6 °C for the building in free floating conditions, according to climate and insulation level. External surface temperatures are reduced above 6 °C during the peak irradiation hours. © 2015 Elsevier B.V. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
