Numerical Analysis on Conceptual Feasibility of Hybrid Windcatcher and Turbine Roof Ventilator for Optimum IEQ and Wind Power Harvesting

This paper introduces "SmartTURVENT," a hybrid windcatcher and turbine roof ventilator system with triple benefits: enhancing indoor environmental quality (IEQ), harnessing renewable energy, and reducing carbon emissions. Utilising a transient state pressure-based solver with CFD airflow modeling, the SmartTURVENT system optimises heat exchange, achieving about 6-40% and 11-55% faster attainment of acceptable humidity levels compared to individual windcatcher and turbine roof ventilator operations, respectively. In energy harvesting, SmartTURVENT generates 0.37 W, 11.27 W, and 69.10 W at wind speeds of 2 m/s, 5 m/s, and 10 m/s, respectively. Over an 8-hour operation, SmartTURVENT reduces carbon emissions by an average of 13.0% compared to conventional systems

Low energy housing retrofit in North England: Overheating risks and possible mitigation strategies

In the drive to reduce space-heating demand and associated CO2 emissions as well as tackle fuel poverty, dwelling overheating and summer-time occupant thermal discomfort might be the unintended consequences of low-energy building retrofits. This paper presents the findings of a steady-state modelled low energy retrofit dwelling in northern England and its potential current and future climate overheating risks using UK Climate Projections 2009 (UKCP09) scenarios (2050 and 2080 High Emission Scenarios). Predictive findings highlight that retrofitting to low energy standards increases overheating risk over time, unless passive prevention measures are included in the retrofit design. In addition, the steady-state nature of the model might not fully capture the occupants’ exposure to actual future overheating risks. Among the most effective individual passive overheating mitigation strategies are temporary internal shading, permanent external shading, and night-time ventilation. Most effective is a combination of these adaptation measures, so that predictive overheating is minimised in a future changing climate, reducing the uptake of active cooling in retrofitted dwellings. Practical applications: Much research focuses on building overheating risks in the warmer South-east of England. However, this paper highlights how dwelling retrofit in north England (Sheffield) also can lead to increased dwelling overheating risk, unless passive design measures are included in the retrofit design. Among the most effective individual passive overheating mitigation strategies are solar shading devices and increased night-time ventilation, though ideally different measures are combined. Using future climate scenarios highlights that retrofits designed today might not be able to provide occupant thermal comfort in a future warming world

SmartTURVENT: Conceptual and Feasibility Studies of Smart Hybrid Windcatcher and Turbine Roof Ventilator for Indoor Environmental Quality (IEQ) Enhancement and Wind Energy Harvesting

Shifting from fossil fuel-based power and dive into clean energy solutions are strived for 2030 and 2050 under the SDG agenda. There is huge potential to convert roof ventilators as ventilation to energy technologies via taking advantage of low-high pressure zones and natural-driven force. The buoyancy of indoor ventilation can be more effective by inducing higher pressure and temperature differences. Therefore, a hybrid of two ventilation systems was emphasised in thisresearch to enhance indoor environmental quality, renewable energy harvesting, and carbon saving. A feasibility study of “SmartTURVENT”, a new concept design integrating windcatcher, turbine roof ventilator, and heat-and-cool recovery unit was proposed using thermal airflowmodelling. ANSYS Fluent transient state pressure-based solver with Energy, Species Transport and Realizable K-Epsilon models was employed based on decoupled geometry domain approach which segregated a domain of SmartTURVENT operation in indoor-outdoor environment and a domain simulating a turbine rotation. Smooth Dynamic Mesh with Six DOF properties was employed to permit the turbine blade rotation thus obtain tangential velocity and torque. Theparameters of the evaluation included operational settings, ambient condition, and wind speed. From the findings, the hybrid operation could reach an indoor comfort within acceptable humidity 60.0 % and 80.0 % faster than the single operation of wind catcher and turbine roof ventilator, respectively. By turning on the heat/cool recovery unit, the system was able to improve the condition of the incoming air based on the evidence of drastic temperature changes. However,high speed incoming air could not prolong the heat recovery process and caused the temperature stability. On energy harvesting, SmartTURVENT could generate 0.37 W, 11.27 W and 69.10 Wfrom 2 m/s, 5 m/s, and 10 m/s wind speed, respectively. While under an 8-hour room operation, the average carbon saving by incorporating SmartTURVENT was 13.0 %, as compared to a conventional operation