Mohammed Mayhoub

• PhD
• Professor at Al-Azhar University

Globally building sector consumes a significant amount of fossil fuel-generated grid energy which emits a considerable level of carbon emissions. These scenarios can be an obstacle to sustainable or smart city developments. In a building which consists of various components, windows are the most influential to contribute to this energy consumption....

In daylighting performance simulations of façade systems, a trade-off is often required between processing speed and prediction accuracy. This is particularly relevant at design onset, where plausible simulation outcomes are essential to drive decisions between several alternative façade configurations. To help address this trade-off, this paper pr...

Window shading control is motivated by many reasons. Very few studies consider the influence of non-physical factors that underpin occupant motives for shading control. A candidate reason that concerned this study was cultural differences. Diverging values, beliefs and norms can lead to different design considerations for building architecture to a...

Despite the abundance of daylight in hot desert climates, deep-plan office buildings still lack the provision of sufficient daylight. Although tubular daylighting devices (TDDs) offer a potential solution, they may have visual and economic consequences. Therefore, the present study evaluated the visual comfort, overall energy consumption, and econo...

As a concept, an indoor soundscape is an innovative approach to building environments with a shape that "sounds good," meeting the preferences and needs of the occupants and established according to their unique indoor soundscape perception. This paper presents the assessment of the indoor soundscape regarding objective acoustic parameters such as...

Given the rapid rise in the efficiency of artificial lighting systems, the challenges for any daylighting system on the basis of energy savings will be more challenging in the future. To sustain the role of daylighting in shopping malls, a field survey was conducted to explore daylighting benefits from the customers’ perspective. By analyzing the d...

Tubular daylight guidance systems were developed to introduce daylight into the building’s core. Operating the system in desert climate regions, where both solar irradiance and dust resources are abundant, exposes them to dust accumulation that significantly reduces the system’s efficiency. An experimental investigation was conducted in Cairo to un...

Whilst simulation techniques for predicting building performance are maturing, questions still arise as to how key input assumptions, such as user control, ultimately affect the resultant predictions. A sensitivity analysis was performed to identify the impact of blinds control on daylighting and energy simulations. The analysis was performed on a...

Building core sunlighting systems (BCSS) are developed to deliver daylight where it can not be delivered by the conventional methods. A brief history is given of researches and developments into the BCSS over the last fifty years, in addition to a short description of the technologies and components of eighteen fully developed or commercialized sys...

Sunlight directing systems (SDS) are used in façade design to improve visual comfort, avoid direct sunlight and reduce energy consumption. A successful application of the SDS is based on how to control light bounces in accordance with distinctive characteristics of SDS. In addition to the factor of cross-section design which, in particular, can lar...

The economic feasibility of innovative daylighting systems (IDS) is usually estimated without considering the impact of cleaning costs. This study determines the most sensitive parameters affecting the cost of cleaning, whether the process is manual or automated. The net present value method was used to estimate the payback period of investments in...

Innovative daylighting systems (IDS) are used to deliver daylight into windowless spaces and building cores. Cleaning the exposed surfaces is essential for maintaining their efficiency because the accumulation of dirt inhibits their effectiveness. However, a review of the literature has indicated that this issue has not received the attention it de...

The economic efficiency of building core sunlighting systems (BCSS) that are used to deliver sunlight into building core is essential for their widespread use. This study analyses the costs and benefits of using the BCSS through a parametric evaluation process considering key parameters, such as installed and saved lighting power, electricity costs...

The utilisation preference of glazed facades in the hot regions is accompanied by serious environmental and economic impacts. Attempts are continuing to fulfil an optimum balance between minimising heat gains and maximising daylighting benefits; in an economical approach. This study was conducted in Egypt, where a real case study was investigated t...

Dual ducting: An innovation to increase the use of daylight in buildings. Lighting Research and Technology, DOI: 10.1177/1477153514548472. © Copyright 2014 [please consult the authors] Notice: Changes introduced as a result of publishing processes such as copy-editing and formatting may not be reflected in this document. For a definitive version of...

The innovative daylighting systems (IDS) seek to meet the illumination requirements in buildings, where inadequate amount of daylight is provided by the conventional daylighting systems. Many IDS have been commercially launched, but challenges, such as high initial cost, utilization difficulties, and application limitations, prevent their widesprea...

Hybrid lighting systems simultaneously deliver daylight and electric light into the core of a building where they are combined and distributed via luminaires. The systems have only been developed in the last few years and accordingly there is little accumulated experience of light delivery or design methods. This paper presents measured data for a...

This paper presents universal models and constant values to estimate luminous efficacies for each of global and diffused solar radiation on a horizontal surface. They are applicable to all sky conditions and are based on satellite derived data available via web servers. Solar radiation data from ten locations in Europe and North Africa was used to...

Daylight guidance systems are linear devices that channel daylight into the core of a building. This paper analyses costs and benefits of using the two main classes of daylight guidance to light offices as an alternative to conventional electric lighting. The work demonstrates that daylight guidance is generally not economical using conventionally...

This paper presents a universal model of luminous efficacy for direct solar radiation on a horizontal surface. The model is applicable to all sky conditions and is based on data obtained from satellites and available via web servers. Solar radiation data from 10 locations in Europe and North Africa has been used to obtain four functions for luminou...

This paper reviews developments in hybrid light guidance systems. In these daylight and electric light are simultaneously delivered into a building where they are combined and distributed via luminaires. The technology used in hybrid systems, both conceptual and realised, is discussed. The review speculates as to their likely performance in terms o...

Hybrid systems simultaneously deliver daylight and electric light into a building where they are combined and distributed via luminaires. Hybrid technology, both conceptual and realised, is discussed together with that of the more established of tubular daylight guidance lighting systems. Likely system performance in terms of daylight delivery and...