In this study, focusing on comfort time, the effect of phase change material (PCM) presence in ten climatic zones with an average temperature of 13.1–26.9 °C, cooling degree-days of 2500–6700 and heating degree-days of 400–2800 were discussed. Numerical results were deduced by developing energy equations for the whole building along with momentum and continuity equations for PCM. The results showed that for all regions adding PCM significantly increases comfort time. If the PCM is installed closer to the indoor, its comfort time is longer than other locations. To select a suitable PCM, five materials with a melting temperature in the range of 18–24 °C were selected and it was observed that a suitable PCM has a slight dependence on the comfort temperature range. By defining the comfort range 18–27 °C, it was found that for a simple building (without PCM), the comfort time percent varied in the range of 26–40%. With the addition of PCM, it was observed that the comfort time percent varied in the range of 54–82%. In other words, in the presence of a suitable PCM without energy consumption, the internal temperature can be set in the range of 18–27 °C up to 82% in a year. In this scenario, PCM-22 was suitable for six regions (out of ten regions). For scenarios of 20–25 °C, it was found that PCM-23 was suitable for eight regions. If PCM-23 was added to conventional buildings, without energy consumption at least in 54% of a year, the temperature can be set in the range of 20–25 °C. 

Buildings with less HVAC power demand by incorporating PCM into envelopes taking into account ASHRAE climate classification

Advances in building-integrated photovoltaic (BIPV) systems for residential and commercial purposes are set to minimize overall energy requirements and associated greenhouse gas emissions. The BIPV design considerations entail energy infrastructure, pertinent renewable energy sources, and energy efficiency provisions. In this work, the performance of roof/facade-based BIPV systems and the affecting parameters on cooling/heating loads of buildings are reviewed. Moreover, this work provides an overview of different categories of BIPV, presenting the recent developments and sufficient references, and supporting more successful implementations of BIPV for various globe zones. A number of available technologies decide the best selections, and make easy configuration of the BIPV, avoiding any difficulties, and allowing flexibility of design in order to adapt to local environmental conditions, and are adequate to important considerations, such as building codes, building structures and loads, architectural components, replacement and maintenance, energy resources, and all associated expenditure. The passive and active effects of both air-based and water-based BIPV systems have great effects on the cooling and heating loads and thermal comfort and, hence, on the electricity consumption.

State-of-the-Art Technologies for Building-Integrated Photovoltaic Systems

Using nanoparticles in solar collector to enhance solar-assisted hot process stream usefulness

The growing demand for energy in the building sector drives the need for change from fossil fuels to environment-friendly power sources which can also mitigate the effect of global warming and clim...

Net Zero Energy Consumption building in India: An overview and initiative toward sustainable future

Melting assessment on the effect of nonuniform Y-shaped fin upon solid–liquid phase change in a thermal storage tank

Shallow geothermal systems use the thermal inertia of the earth to provide a temperature gradient between the ambient conditions and the underground soil. This thermal inertia can be used by the heat exchangers to provide space heating and cooling during the winters and summers. This paper provides a brief but broad overview of the different active and passive technologies involved in the use of heat exchangers for HVAC in order to achieve a near net zero energy building. Firstly the different types of ground heat exchangers and heat pumps are introduced along with the relevant studies of significance in this field. It has been demonstrated that the different types of heat exchangers can be integrated with thermally active building envelopes and renewable energy resources to significantly minimize the building energy use. Finally a pathway has been devised for use of ground heat exchangers to realize a net zero energy building.

Irfan Ahmad Gondal

Papers

Prospects of shallow geothermal systems in HVAC for NZEB