4 research outputs found
Human environmental heat transfer simulation with CFD – the advances and challenges
Get PDFThe modelling and prediction of human thermoregulatory responses and comfort have gone a long way during the past decades. Sophisticated and detailed human models, i.e. the active multi-nodal thermal models with physiological regulatory responses, have been developed and widely adopted
in both research and industrial practice. The recent trend is to integrate human models with environmental models in order to provide more insight into the thermal comfort issues, especially in the non-homogeneous and transient conditions. This paper reviews the logics and expectations of coupling human models with computational fluid dynamics
(CFD) models. One of main objectives of such approaches is to take the advantage of the high resolution achievable with the CFD, to replace the empirical methods used in the human models. We aim to initiate debates on the validity of this objective, and to identify the technical requirements
for achieving this goal. A simple experiment with 3D human models of different sizes and shapes is also reported. Initial results shows the presence of arms may be important. Further experiments are required to establish the impact of size and shape on simulation result
Safety precautions in the usage of extension cords by students in halls and hostels
Get PDFThis paper presents the evaluation of the safety measures adopted by Ho Technical University (HTU) students in the use of power extension cords in their halls and hostels, along with their safety considerations for properly selecting these cords to avert fire outbreaks or prevent them from becoming a potential fire hazard. Whenever extension cords are utilized inappropriately it can lead to fire or electric shock perils. The assessment of the awareness level of safety practices is yet to be rigorously pursued as an agenda towards extension cord usage in institutions and agencies perceived to be high energy consumers where fire outbreaks occur frequently. A quantitative research approach was adopted, using a questionnaire for data collection. The findings revealed that about 52% of the respondents did not know the current and power ratings and the effects of overloading the extension cord. It was recommended that consumers purchase extension cords that have been endorsed by an autonomous testing laboratory, whereas the university should immediately organize a seminar to educate the staff and students about the use of the extension cord
Cool Roofs: High Tech Low Cost solution for energy efficiency and thermal comfort in low rise low income houses in high solar radiation countries
Get PDFCool roofs are most effective in reducing cooling loads and alleviating overheating in locations with high solar radiation and external air temperature. This paper presents results of an experimental study of a low income house in Jamaica and a computational study in three countries around the equator: Jamaica, Northeast Brazil (Recife) and Ghana. A case-study typical of single storey houses in Jamaica was monitored before and after the installation of a cool paint on the roof; on days with average solar radiation intensity of ∼420 W/m2 and ambient air temperature of ∼28 °C, internal ceiling surface temperature is reduced by an average of 6.8 °C and internal air temperature by 2.3 °C. Monitoring results were used to calibrate successfully an EnergyPlus model; similar models were developed for Ghana and Brazil differing in size and/or construction to reflect country specific practices. Annual simulations indicate that internal ceiling surface temperatures are reduced on average by 3.2–5.5 oC and internal air temperatures by 0.75–1.2 °C. Cooling demand simulations (setpoint 24 °C) indicate similar annual potential savings in the three locations (∼190 kWh/m2/year) although estimated CO2 emissions reduction differ reflecting electricity generation fuels. Aging of the cool roof has an impact reducing load savings by 22–26 kWh/m2/year.This work was carried out as part of EPSRC Global Challenges Research Fund Institutional Sponsorship Award 2016 - Brunel Uni- versity ( EP/P510749/1 )
