Climate Resilient Low-Income Tropical Housing

This is the final version of the article. It first appeared from MDPI at http://dx.doi.org/10.3390/en9060468.Located in East Africa, Uganda is one of the most economically deprived countries that is likely to be dramatically affected by climate change. Over 50% of Ugandan families live in single-roomed overcrowded properties and over 60% of the country’s urban population live in slums. Moreover, the gradual shift towards relatively modern and low thermal resistance building materials, in addition to imminent thermal discomfort due to global warming, may considerably affect the health and wellbeing of low-income people, the majority of whom live in low quality homes with very little or no access to basic amenities. This paper evaluates the effects of various construction methods as well as refurbishment strategies on thermal comfort in low-income houses in Uganda. It is aimed at helping low-income populations adapt to climate changes by developing simple, effective and affordable refurbishment strategies that could easily be applied to existing buildings. Dynamic thermal simulations are conducted in EnergyPlus. The adaptive model defined in BS EN 15251 and CIBSE TM52 is used to evaluate the risk and extent of thermal discomfort. Roofing methods/materials are found to be the key factor in reducing/increasing the risk of overheating. According to the results, roof insulation, painting the roof with low solar absorptance materials and inclusion of false ceilings are, respectively, the most effective and practical refurbishment strategies in terms of improving thermal comfort in low-income houses in Uganda. All refurbishment strategies helped to pass Criterion 3 of CIBSE TM52, as an indicator of “future climate scenarios”, making low-income houses/populations more climate resilient.This document is an output from a research project “Energy and Low-Income Tropical Housing” co-funded by UK aid from the UK Department for International Development (DFID), the Engineering and Physical Science Research Council (EPSRC) and the Department for Energy and Climate Change (DECC), for the benefit of developing countries. The views expressed are not necessarily those of DFID, EPSRC or DECC

Daylighting and solar shading performances of an innovative automated reflective louvre system

Traditional windows, as the major source of daylight, have a common problem which is uneven distribution of daylight in the room. Several innovative daylighting systems such as light shelves, fixed and movable reflective louvres, reflective sills, prismatic glazing, light pipes, etc., have been developed to address this problem. This paper reports on a research programme that investigates retrofitted solutions to uneven distribution of daylight in deep-plan office buildings. The work presented here follows initial investigations into the design and applicability of an automated retrofitted panel thermal shutters which can also act as a sunshade and daylighting system. The system has a patented function which allows each shutter/louvre to be controlled and placed separately from other louvres. This study evaluates the effectiveness of the system when acting as a sunshade, light shelf, reflective louvre, and reflective sill under clear, overcast, and sunny sky conditions. According to the results, the system significantly improved daylight distribution and reduced the need for artificial lighting by 60%.This is the author accepted manuscript. The final version is available from Elsevier via http://www.sciencedirect.com/science/article/pii/S0378778814006355

Offsite Manufacturing: A Survey on the Current Status and Risks of Offsite Construction in Iran

This is the final published version. It first appeared at http://www.davidpublisher.com/index.php/Home/Article/index?id=109.html.Iran needs around 1.5 million residential homes to be constructed annually to answer its cumulative demand by 2025. Given the current situation of the Iranian construction industry, it seems almost impossible to achieve this objective by using traditional methods of construction alone. Offsite manufacturing (OSM) can potentially increase the housing output in Iran thanks to its advantages over traditional methods of construction. However, OSM imposes a different set of risks which should be studied in the Iranian context. This study aims to investigate the readiness of the Iranian construction industry if offsite methods were to be introduced to the country in large industrial scales. To this end, a questionnaire survey was conducted to identify the risks and required actions in order to achieve successful application of these methods. Several subjects including costs, practicality, design and construction processes, demand, governmental policies, technology, and sustainability issues were investigated as the core research areas. The results revealed that, considering the current situations, it would be highly risky to introduce offsite methods of construction to Iran. Research findings highlight some key areas including design and construction processes, economies of scale, governmental supports, and education, which should be addressed to mitigate the identified risks

Effects of Natural Ventilation on Thermal Comfort in Low-income Tropical Housing

This paper evaluates the effects of natural ventilation on thermal comfort and risk of overheating in low-income tropical housing in Uganda. Dynamic simulations are conducted in EnergyPlus to assess various strategies including single sided and cross ventilation, roof vents and night ventilation in case study dwellings. The Chartered Institution of Building Services Engineers Technical Memoranda 52 (CIBSE TM52) is used to assess thermal comfort conditions within the case study dwellings. The results indicate that natural ventilation strategies marginally reduce the risk of overheating. Overall, compared to other strategies, such as roof insulation, natural ventilation is less effective in terms of improving indoor comfort conditions. This paper is a part of a series of publications on the effects of climate change on thermal comfort in low-income tropical housing

Phased Array Systems in Silicon

Phased array systems, a special case of MIMO systems, take advantage of spatial directivity and array gain to increase spectral efficiency. Implementing a phased array system at high frequency in a commercial silicon process technology presents several challenges. This article focuses on the architectural and circuit-level trade-offs involved in the design of the first silicon-based fully integrated phased array system operating at 24 GHz. The details of some of the important circuit building blocks are also discussed. The measured results demonstrate the feasibility of using integrated phased arrays for wireless communication and vehicular radar applications at 24 GHz

The effects of air permeability, background ventilation and lifestyle on energy performance, indoor air quality and risk of condensation in domestic buildings

Effective and efficient ventilation is essential when improving energy performance and Indoor Air Quality (IAQ) of buildings. Reducing air permeability can considerably improve the energy performance of buildings; however, making the buildings more airtight may result in lower rates of natural ventilation which may in turn increase the risks of condensation and unacceptable IAQ. This study evaluates the effects of different air permeability rates, background ventilation and occupants’ lifestyles on the energy performance as well as the risk of condensation and CO2 concentration in domestic buildings. Dynamic computer simulations were conducted in EnergyPlus. Results indicated direct relations between the ventilation rates, energy performance and IAQ. Higher air permeability along with background ventilation resulted in considerably better IAQ while energy consumption increased by up to four times. Occupants’ lifestyles were identified as a major contributor to the risk of condensation.This is the final version. It was first published by MDPI at http://www.mdpi.com/2071-1050/7/4/4022

Thermal Comfort in Zero Energy Buildings

This paper evaluates thermal comfort in domestic zero energy buildings. Dynamic simulations are used to assess a variation of scenarios including: construction types, natural ventilation strategies, solar shading, and occupancy periods in a low energy case study dwelling, within the United Kingdom. The Chartered Institution of Building Services Engineers Technical Memoranda 52 (CIBSE TM52) is used to evaluate the thermal comfort conditions, and the state of overheating within the case study dwelling. The results indicate that increasing the thermal mass of the external walls significantly reduces the risk of overheating within the case study dwelling. Additionally, the most beneficial window opening profile is night ventilation. The addition of solar shading on the South, East and West elevations considerably improved thermal comfort conditions. Increasing the effective openable glazing area to facilitate natural ventilation in zero energy buildings and further improve the indoor thermal comfort

Code for Sustainable Homes: opportunities or threats for offsite manufacturing and mass-customization?

This study intends to, firstly, discuss current status of zero carbon homes in the UK, and secondly, to investigate the feasibility of using offsite construction methods to deliver mass customised zero carbon homes. The study concludes that mass customised offsite housing could be an answer to overcome the current barriers to achieve zero carbon homes in the UK; however, more work is required to increase the confidence of stakeholders including clients, designers, and housebuilders in offsite manufacturing in order to increase the share of such methods in the construction industry

Delivering Sustainable Low-Income Housing in Uganda, Challenges and Opportunities

While the developed world is adapting to the consequences of climate changes, global warming will negatively affect the quality of life and economic growth in developing countries. The low-income populations from low and medium Human Development Index (HDI) countries would suffer even more from climate changes because of their vulnerable living conditions and the lack of appropriate and adequate infrastructure. Particular attention should therefore be paid to the low-income housing conditions not only to address the environmental concerns but also to improve the living standards and health and wellbeing of low-income populations. This paper reviews the Ugandan housing conditions in order to identify the opportunities and challenges for delivering sustainable energy efficient low-income housing in Uganda. Urbanisation; slums; housing costs, types and sizes; construction methods and materials and renewable energy sources are some of the areas which have been reviewed and discussed in detail. The findings reveal some critical areas such as informal settlement, overcrowding and access to housing facilities as well as embodied energy of construction methods and materials which require immediate attention

Imipenem resistance in clinical Escherichia coli from Qom, Iran

OBJECTIVE: The emergence of metallo-\u3b2-lactamase-producing Enterobacteriaceae is a worldwide health concern. In this study, the first evaluation of MBL genes, bla IMP and bla VIM , in Escherichia coli resistant to imipenem isolated from urine and blood specimens in Qom, Iran is described. Three hundred urine and blood specimens were analysed to detect the presence of E. coli. Resistance to imipenem and other antimicrobials was determined by disk diffusion and MIC. MBL production was screened using CDDT. PCR was also carried out to determine the presence of bla IMP and bla VIM genes in imipenem-resistant isolates. RESULTS: In total, 160 E. coli isolates were collected from March to May 2016. According to disk diffusion, high-level of resistance (20%) to cefotaxime was observed, whereas the lowest (1%) was detected for tetracycline. In addition, five isolates showed resistance to imipenem with a MIC\u2009 65\u20094 \ub5g/mL. CDDT test confirmed that five isolates were MBL-producing strains, but no bla IMP and bla VIM genes were detected. Results of this study show a very low level of resistance to imipenem in our geographical area