Energy Performance of Office Buildings in Ghana

The parametrical measures that could improve the thermal performance of a sample of five existing buildings in Kumasi, Ghana were explored through a simulation application. These buildings are representative of the majority of existing low-rise office buildings in Kumasi and house different functions (university offices, private companies, municipal offices, etc.). The applied cooling systems typically involve split air-conditioning units. The simulation models were calibrated using indoor and external environmental conditions measured over a period of 12 months. This process led to a consistency of the simulation results which demonstrate that the use of efficient windows and natural ventilation can improve the buildings' energy performance. Explicitly, combined scenarios of efficient windows, natural ventilation, attic floor insulation and efficient electrical lighting resulted in a significant reduction (between 25 and 45%) of the buildings' cooling loads.Keywords: Energy, Efficient, Simulation, Improve, Cooling Loa

The evaluation of occupants’ behaviour and preferences in office buildings in Ghana

Over a period of one year, five office buildings in Ghana have been studied and the occupants were interviewed to assess the operation and accessibility of system and system controls at their working environment. In all, 64 occupants were interviewed. The results show that occupants in office buildings have a strong urge to operate windows, even in air-conditioned buildings. Satisfaction in office environment was found to correlate with the flexibility of building systems, system controls and personalisation of workspace. In addition, to increase the efficiency of building systems, occupants need to be trained in the proper use of the facilities available at their workspaces.The results of the evaluation serve to contribute to the process of refinement and improvementin office buildings

The Effects of Form and Orientation on Energy Performance of Residential Buildings in Ghana

The form and orientation of a building can have an effect on energy performance. The difficulty has been to find the most energy efficient form-aspect ratio. In this paper, a volume with differ-ent aspect ratios has been used to investigate the effect on energy performance (cooling load). The volume used is of the same construction and an hourly dynamic simulation programme was used for the analysis. It was evident that the square form was the most energy efficient whiles elongated forms used much energy. However, since spaces could warm up when oriented to-wards the east and west, the authors further recommend a detailed look into the function of spaces in design schemes and the use of simulation for design alternatives.Keywords: Form, Orientation, Energy Performance, Cooling Loa

Simulation Based Analysis On The Effects Of Orientation On Energy Performance Of Residential Buildings In Ghana

Since the energy crisis in 2007, energy performance of buildings is gradually becoming an issue in Ghana. The authors of this paper used simulation as a tool to analyse three conventional resi-dential building types, in order to see the effects of orientation on energy performance, specifi-cally on cooling loads. The three building types; a single storey square block, a single storey rec-tangular block and a two storey square block with different thermal properties were modelled and simulated. Alternate north angles were used and results compared for the best orientation resulting in minimum cooling loads in the climatic context of Kumasi, Ghana. The results on the rectangular building indicated the best orientation as being north and south. No particular ori-entation could be recommended for the single and two storey building (with square plans) and this showed that the influence of other factors such as windows, configuration and function of spaces, and building mass directly affected cooling loads and eventually orientation.Keywords: Simulation, Orientation, Energy Performance, Cooling Load, North Angl

Contrasting the Principles behind the Orientation of Building Forms and Location of Spatial Components around the Globe

Building designers are advised to use sustainable design measures in order to make spaces comfortable, before applying mechanical systems. An important aspect of sustainable design is orientation, specifically the rule to orient buildings to the north and south. However, in an attempt to employ this sustainable principle, various cultures resort to different myths as means of justification. The paper presents historical and modern views and theories on orientation of building forms, spatial components, and the surrounding myths worldwide. The results showed that even though the recommended orientation is mostly the north-south, the myths around this measure are sometimes rooted in the culture of places. For instance, the Chinese, many of whom practice the Feng Shui theory, support design recommendations that follow the flow and balance of positive (yang) and negative (yin) energies. Furthermore, room heights between 3 and 3.5 metres, centrally placed dining spaces and main entrance to buildings in the South are common principles worldwide

The Use of Natural Lighting in Students’ Hostels: A Case Study of Ayeduase, a Suburb of Kumasi, Ghana

The role that natural lighting plays in buildings cannot be underestimated. Natural light is integrated into buildings because of its potential economic benefit and the effect on the occupants’ psychological and physiological well-being. This study concentrates on Ayeduase, a suburb of Kumasi, Ghana, where students live in hostels with poor architectural design. Therefore, the primary aim of this study is to investigate the health and visual comfort of students living in Ayeduase, by creating awareness of the positive effects of natural light on humans. Questionnaires and interviews, as well as empirical measuring of daylight levels in the spaces of selected hostels were used. Analysed data revealed that the level of illuminance in the hostels is considerably poor and this resulted in students using artificial lighting throughout the day. Nevertheless, the negative effect of this situation can be prevented from occurring in further developments in Ayeduase (and Ghana as a whole), by educating designers on the benefits of using natural lighting in buildings and by enforcing laws that will ensure that buildings have maximum openings that allow enough daylight into the interior spaces. These measures will help reduce utility costs, improve the well-being of building occupants and increase the performance of students.Keywords: Natural Lighting, Building Science, Occupants, Perceptio

A holistic survey of dampness in a six bedroom residential apartment

As one of the most damaging failures that occur in buildings, dampness in all its forms affects both old and modern types of buildings. As an important function, buildings should seek to prevent water penetrations and give envelop to their occupants. This study adopted a holistic approach to dampness surveying to identify and document the areas in a six bedroom residential building severely affected by dampness. A case study approach which involves a three-stage protocol of damp investigation, thus visual inspection, non-destructive tests using a moisture meter and destructive testing was used in the study to identify and document areas in the building severely affected by dampness. The results from the visual investigation showed that dampness was seen on the external and internal walls of the building and was accompanied by symptoms such as damp patches in horizontal bands, blistering of paint, surface efflorescence, stains and in some portions mould growth. A further investigation with the moisture meter showed that the problem was very pronounced in the walls located in the western orientation. Also, destructive tests revealed that the dampness in the bathrooms and kitchen were due to plumbing leakages and rain water penetration respectively. Further research on affected buildings situated in different ground conditions is recommended. This study should serve as a platform for further studies to be conducted on the building in order to trace the visible evidence back to the actual seat of the problem. In so doing, it should provide a platform for all stakeholders in the construction industry to come together to address this common but dangerous problem.Keywords: Dampness, residential buildings, plumbing leakage, rising damp, water penetratio

Expectant management of early onset of severe pre-eclampsia in Durban

Fifty patients with severe pre-eclampsia who presented before 32 weeks' gestation were managed conservatively (sedation, bed rest, antihypertensive therapy and intensive fetal and maternal monitoring) until intervention was indicated. Twelve patients presented before 26 weeks ofpregnancy and there were no fetal survivors in this group; 23 presented between 26 and 29 weeks and 8(34,8%) of the babies in this group survived. The rate of perinatal loss in those presenting between 30 and 32 weeks was 26,6% (N =4). Patients who had a history of a hypertensive disorder in their previous pregnancy(ies) had a higher perinatal mortality rate; 23 such mothers experienced 16 perinatal losses compared with 27 mothers who had no such history and who had only 8 perinatal losses. There was 1 maternal death, there were 2 cases of eclampsia, 3 of pulmonary oedema, 4 of abruptio placentae and 1 case of renal failure; 2 patients had disseminated intravascular coagulation. The local indigent and underprivileged black population have a more aggressive form of early onset of severe pre-eclampsia than that reported for other population groups. The high maternal complication rate of 30,8% and the low fetal survival rate before 26 weeks indicate that there is no place in our setting for expectant management of severe pre-eclampsia in patients presenting before 26 weeks. This applies particularly to those with a previous history ofhypertension in pregnancy

A psychrometric analysis of thermal comfort In low-rise office buildings in Ghana

A research project on the thermal performance of office buildings in Ghana was conducted and in the process, data loggers were used to record indoor environmental conditions over a period of 12 months in five office buildings. The temperature and relative humidity values recorded were analysed and plotted on psychrometric charts. The results of the study in 15 offices wereplaced in psychrometric charts which showed uncomfortable indoor environmental conditions. The reasons were high relative humidity values, although the temperatures in most of the cases were below 29°C. The impression gained during the observation period was that occupants hadadapted to high humidity levels and therefore found maximum humidity levels of 80% comfortable, provided temperature values did not exceed 29°C. This significant clue calls for further study and the adjustment of the comfort scale for the climatic context of Kumasi, Ghana

Hydrochemical Evolution of Ground and Surface Water within the Amansie and Adansi Districts of the Ashanti Region, Ghana

Source–rock deductions of major ions and saturation states of minerals in groundwater were employed to determine the origin of dissolved ions and the thermodynamic controls on the groundwater composition respectivelyin groundwater within the Amansie and Adansi Districts. Results show that, silicate weathering and ion-exchange reactions are the major processes influencing groundwater chemistry within the Districts. The main objective of this study is to characterize groundwater and delineate soil-water-rock interactions responsible for the chemical evolution of groundwater within the districts. Fifty-nine boreholes, twelve wells and two stream samples were collected for quality assessment. Results also show that groundwater within the districts is strongly to moderately acidic as, 62 % of the groundwaters has pH that range 3.6 - 6.0. Acidity in ground and surface water within the districts is attributable predominantly to natural processes than mining activities; however, the groundwaters still have the potential to neutralize acids due to the presence of silicates/aluminosilicates. The waters are fresh (EC< 500 μS/cm) with conductivity values which ranged 22.8 – 473 μS/cm, and a mean value of 172.9 μS/cm. TDS of the groundwaters ranged 14.9 – 309.8 mg/L with a mean value of 112.6 mg/L. The relative abundance of cations and anions are in the order: Ca2+ > Na+ > Mg2+ > K+ and HCO3- > Cl- > SO42-respectively. The states of saturation of the groundwaters with respect to major minerals using hydrogeochemical transport model Phreeqc for Windows suggest that, anhydrite and gypsum are subsaturated and indicates that, groundwater within the districts originates from a formation with insufficient amount of these minerals in solution or short residence time of these minerals with groundwater within the districts.Two principal hydrochemical water types; Ca-Mg-HCO3 and Na–Cl have been delineated, with Ca-Mg-SO4, Na-Mg-Ca-HCO3 and Na- Cl-SO4 as minor water types. Groundwater within the districts principally evolves from fresh Ca–Mg–HCO3 type water into Na–HCO3 type water into Ca–Mg–Cl type water into Na–Cl type water along its flow path due to ion-exchange reactions and therefore, largely characterized by recharge processes through mixing with waters of geochemically different ionic signatures