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Ting Qi

Bio: Ting Qi is an academic researcher from Xi'an University of Architecture and Technology. The author has contributed to research in topics: Cooling load & Solar gain. The author has an hindex of 1, co-authored 1 publications receiving 15 citations.

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Journal ArticleDOI
TL;DR: In this article, three types of PV rooftops, namely, horizontally-mounted overhead PV rooftop, tilted overhead PV roof, and attached PV rooftop are studied to explore their impacts on the heat gain and heat loss of the roof and building's heating and cooling load.

33 citations


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01 Jan 2016

1,633 citations

Journal ArticleDOI
TL;DR: In this article, a review of various factors that affect the design and performance of building-attached and building integrated photovoltaic (BIPV) system applications is presented.
Abstract: Integration of photovoltaic (PV) technologies with building envelopes started in the early 1990 to meet the building energy demand and shave the peak electrical load. The PV technologies can be either attached or integrated with the envelopes termed as building-attached (BA)/building-integrated (BI) PV system. The BAPV/BIPV system applications are categorized under the building envelope roof and facades as PV-roof, PV-skin facade, PV-Trombe wall, PV claddings, and louvers. This review covers various factors that affect the design and performance of the BAPV/BIPV system applications. The factors identified are air gap, ventilation rate, a tilt angle of PV shading devices, adjacent shading, semitransparent PV (STPV) glazing design, cell coverage ratio (CCR), transmittance, window to wall ratio (WWR), and glazing orientation. Furthermore, the results of the possible factors are compared to building locations. This review article will be beneficial for researchers in designing the BAPV/BIPV system and provides future research possibilities.

35 citations

03 Aug 2010
TL;DR: In this paper, the effect of rooftop PV systems on the building roof and indoor energy balance as well as their economic impacts on building HVAC costs have been investigated, and the authors report extensive measurements of a building containing a flush mount and a tilted solar PV array.
Abstract: Building Heating, Ventilation and Air Conditioning (HVAC) is a major contributor to urban energy use. In single story buildings with large surface area such as warehouses most of the heat enters through the roof. A rooftop modification that has not been examined experimentally is solar photovoltaic (PV) arrays. In California alone, several GW in residential and commercial rooftop PV are approved or in the planning stages. With the PV solar conversion efficiency ranging from 5-20% and a typical installed PV solar reflectance of 16-27%, 53-79% of the solar energy heats the panel. Most of this heat is then either transferred to the atmosphere or the building underneath. Consequently solar PV has indirect effects on roof heat transfer. The effect of rooftop PV systems on the building roof and indoor energy balance as well as their economic impacts on building HVAC costs have not been investigated. Roof calculator models currently do not account for rooftop modifications such as PV arrays. In this study, we report extensive measurements of a building containing a flush mount and a tilted solar PV array as well as exposed reference roof. Exterior air and surface temperature, wind speed, and solar radiation were measured and thermal infrared (TIR) images of the interior ceiling were taken. We found that in daytime the ceiling surface temperature under the PV arrays was significantly cooler than under the exposed roof. The maximum difference of 2.5 C was observed at around 1800h, close to typical time of peak energy demand. Conversely at night, the ceiling temperature under the PV arrays was warmer, especially for the array mounted flat onto the roof. A one dimensional conductive heat flux model was used to calculate the temperature profile through the roof. The heat flux into the bottom layer was used as an estimate of the heat flux into the building. The mean daytime heat flux (1200-2000 PST) under the exposed roof in the model was 14.0 Watts per square meter larger than under the tilted PV array. The maximum downward heat flux was 18.7 Watts per square meters for the exposed roof and 7.0 Watts per square meters under the tilted PV array, a 63% reduction due to the PV array. This study is unique as the impact of tilted and flush PV arrays could be compared against a typical exposed roof at the same roof for a commercial uninhabited building with exposed ceiling and consisting only of the building envelope. Our results indicate a more comfortable indoor environment in PV covered buildings without HVAC both in hotter and cooler seasons.

23 citations

Journal ArticleDOI
01 Sep 2021-Energy
TL;DR: In this paper, the authors presented a technical, economic, and environmental evaluation of a residential building powered by hybrid intermittent generation systems in a mild humid subtropical climate zone in China.

21 citations

Journal ArticleDOI
TL;DR: In this article, the authors proposed a novel technique to prevent the reverse breakdown and mitigate the hot spot temperature of the PV cells under partial shading by reducing reverse current through automated reconfiguration of PV array.

20 citations