abstract
This paper presents an experimental study on the impact of reflective coatings on indoor environment and
building energy consumption. Three types of coatings were applied on identical buildings and their per-
formancewas comparedwith three sets of experiments in both summer andwinter. The first experiment
considers the impact of coatings on exterior and interior surface temperatures, indoor air temperatures,
globe temperature, thermal stratification and mean radiant temperatures for non-conditioned build-
ings (free-floating case); the second one focused on the impact of coatings on reduction of electricity
consumption in conditioned spaces; in the third experiment, the impact of different envelope mate-
rial properties equippedwith different coatingswas investigated. The results showed that, depending on
location, season and orientation, exterior and interior surface temperatures can be reduced by up to 20 ◦
Cand 4.7 ◦5071
C respectively using different coatings. Themaximumreduction in globe temperature andmean
radiant temperature was 2.3 ◦
C and 3.7 ◦
C in that order. For the conditioned case, the annual reduction in
electricity consumption for electricity reached 116 kWh. Nevertheless, the penalty in increased heating
demand can result in a negative all-year effect in Shanghai, which is characterized by hot summers and
cold winters.
© 2010 Elsevier B.V. All rights reserved.1. Introduction and background
Solar radiation incident on building envelope can be absorbed,
reflected and transmitted and it influences interior and exterior
surface temperatures, heat flow entering the building, and hence
indoor thermal environment. Increasing the envelope reflection
coefficient (exterior surface reflectivity weighted by the spectral
energy distribution and integrated over the solar spectrum) results
in reduced absorbed solar radiation and reduced surface tem-
peratures, which allow reduction of conduction heat transfer to
the building interior. Utilization of solar reflective coatings has
shown great potential to reduce solar heat gain, cooling loads and
peak power loads while improving indoor thermal conditions. The
following sections present a short literature review on previous
studies with reflective coatings.
1.1. Previous experimental studies—the impact of reflective
coatings on surface and indoor air temperature
A number of studies on reflective coatings have been carried out,
commonly focusedonwarmclimates andsummer conditions.Moststudies on this topic are experimental and contain measurements
of reduction in interior and exterior surface temperatures and their
impact on room air temperature. Givoni and Hoffman [1] com-
pared the resulting indoor temperature for unventilated buildings
in Israel and they reported that it could be 3 ◦C cooler in the sum-
mer when the buildings were painted white compared with when
painted grey. Synnefa et al. [2] reported “cool materials” for build-
ings and other urban surfaces application, and measured a surface
temperature reduction of 4 ◦C forwhite concrete tilewhen painted
with reflective coatings. Cheng et al. [3] performed experiments
with test cells to investigate the influence of envelope color on
indoor temperatures under hot and humidweather condition. They
showed that the maximum difference of inside air temperature
between a black and a white cell was about 12 ◦C for lightweight
construction. Taha et al. [4] measured the reflectivity and surface
temperatures of variousmaterials used in urban surfaces and found
that white electrometric coatings with a reflectivity of over 0.72
could be as high as 45 ◦C cooler than black coatingswith a reflectiv-
ity of 0.08. Bansal et al. [5] performed experiments under different 室内环境和反射涂层对建筑能耗影响英文文献和翻译:http://www.youerw.com/fanyi/lunwen_1963.html