Chuck Yu

A review of the emission of VOCs from polymeric materials used in buildings

Abstract Building and furnishing materials and consumers products are important sources of formaldehyde and other volatile organic compounds (VOCs) in the indoor environment. The emission from materials is usually continuous and may last for many years in a building. The available evidence indicates that VOCs can cause adverse health effects to the building occupants and may contribute to symptoms of ‘Sick Building Syndrome’. Control of VOC emission should increasingly become an important consideration for the design and manufacture of polymeric materials used in buildings. The EC Construction Products Directive ‘Essential Requirements’ set a framework for limiting the use of materials that could pose a health risk to building occupants. Furthermore, the on-going development of voluntary labelling schemes and data bases of material emissions that could be used by building designers, should further strengthen the demand for ‘low VOC emitting’ products. This paper reviews available information about the emission of VOCs from polymeric building materials, the level of emissions in the indoor environment and the requirements for testing of the materials.

Building Pathology, Investigation of Sick Buildings -Toxic Moulds

This paper considers the requirements for investigation of sick buildings including some guidelines for assessment of exposure risks with a particular focus on dampness, proliferation of moulds, and dispersion of fungal spores in indoor environments. Building pathology, indoors air quality management and management of bio-deterioration, and health problems in buildings are complex issues requiring multi-disciplinary investigations and environmental monitoring. Lack of maintenance, chronic neglect, and building defects leading to water ingress, condensation, and dampness in the building fabric will often produce proliferation of pathogenic toxic moulds, and other microbial and biological effects that could cause allergic response in sensitive people and generally lead to ‘‘sick buildings.’’ A general guide has been provided by this paper for environmental assessment of toxic moulds in indoor environments, including a suggested guideline for assessing the threshold levels for fungal spores in indoor air.

Long-term Impact of Formaldehyde and VOC Emissions from Wood-based Products on Indoor Environments; and Issues with Recycled Products:

This paper discusses the emission of formaldehyde and VOCs from wood-based panel products and the effect on indoor air quality (IAQ). The formaldehyde concentration monitored in four energy efficient test houses over a 7-year period has been included to illustrate the long-term effect of emissions from E1 wood-based panels used in dwellings. Formaldehyde emissions from wood-based floorboard obtained from investigation of sick buildings are included for comparison. Also discussed was the impact of fitting of a “low formaldehyde emitting” wardrobe in an energy-efficient test house and in an apartment home. The exposure risk of an individual unpacking the packages of the flat-packed wardrobes and during assembly was illustrated by measurement made in a 22 m3 chamber and in a test house. A variety of VOCs can be released from wood-based panels and associated materials. There is also a concern about the possible emission of wood preservative residues, such as pentachlorophenol from products made from contaminated wood sources. To minimise impact of formaldehyde and VOC emissions in homes and other buildings, building developers and designers should insist on certification of products based on available labelling schemes and this is required in some countries for assessment of Green Buildings.

Indoor Environmental Quality - Standards for Protection of Occupants' Safety, Health and Environment

Buildings represent a major investment, not just at the design and construction stage, but throughout their service lives because of on-going operational and maintenance. Increasingly owners and occupiers are becoming aware of the importance to maintain an adequate built environmental quality that is attractive and acceptable for the intended occupants. Achieving occupant comfort, including consideration of ventilation, thermal and glare and prevention of adverse health risks can have consequent benefits for occupant productivity and satisfaction, which could maximise the letting/selling potential of the property. Creating and maintaining a comfortable, healthy, efficient and cost-effective indoor environment is a complex task that involves understanding the capabilities and interactions of a range of systems, technologies and building materials as well as occupant requirements. There is a need to form an overall strategy for building design and management to incorporate occupant needs within the concept of ‘sustainable development’. Indoor air scientists have long argued that control of emissions from the building materials and consumer products used in buildings should be an important part of policies and actions to protect public health from the adverse effects of indoor air pollution [1–4]. The response from product manufacturers and regulators in the past can be described as variable and on the whole disappointing. In Europe for example a few countries and some producers have made important steps whereas others have yet to effectively address indoor air quality (IAQ). The issue is now rising up the agenda particularly because of concerns that changes to building design to adapt to the expected effects of climate change could have an adverse impact on IAQ [5,6]. However, there is a continuing need to raise awareness of the issue; for example the UK government’s Code for Sustainable Homes has a section on ‘health and well being’ of occupants without mention of IAQ. Increasingly, buildings are required to be highly air-tight and insulated to meet the ‘‘zero-carbon’’ objectives of governments and this has implications for indoor environmental quality [7]. To minimise the occupants’ exposure risks to indoor pollutants and to enhance environmental quality of buildings, there is a need to consider guidelines [8] and standards for buildings including criteria for ventilation, materials emissions and IAQ criteria for indoor air pollutants such as total VOCs (TVOC), benzene, formaldehyde, carbon monoxide, nitrogen dioxide, microparticulates and polyaromatics [9], as well as microbial contaminants, for example toxic moulds [10]. The scientific literature contains many reports of IAQ problems arising from the use of particular products that release chemicals causing odour and irritation or resulting in an

Energy demand for hot water supply for indoor environments: Problems and perspectives

Supply of hot water, including space heating and domestic hot water (DHW), is very important for the creation of indoor environment. Hot water is not only the most important source for space heating in winter, but also widely used for bathing, washing, swimming and so on. It is not exaggerated to say that human being cannot live without hot water. The building energy consumption contributes 30– 40% to the total energy consumption in developed countries, and about 15–25% in developing countries. 1 The energy consumption breakdown by end uses in developed countries is summarized in Table 1. 1,2 In residential sector, space heating uses 20–50% and DHW, 10–20% of the total building energy consumption. In commercial sector, space heating accounts for 15–50% and DHW, 5–10% of the total building energy consumption. The energy consumption ratio related to hot water can reach 40–60% for residential buildings and 20–60% for commercial buildings in developed countries. As for developing countries, using China as a representative, the energy consumption for heating and DHW is shown in Figure 1. 2 The energy consumption related to hot water supply in China can be categorized as: heating in northern urban areas, heating in central urban areas and DHW in urban areas. The energy consumption for heating in northern urban areas was doubled from 72 million ton of standard coal equivalent (Mtce) in 1996 to 153 Mtce in 2008, accounting for 23% of the total building energy consumption. Besides, heating in central urban areas contributes more than 2% and DHW in urban areas contributes slightly less than 2% of the total building energy consumption. As a result, the energy consumption related to hot water supply is currently about 27% of total building energy consumption in China. The energy consumption related to hot water in

Photocatalytic Oxidation for Maintenance of Indoor Environmental Quality

The purpose of this paper is to provide a review of the application of photocatalytic oxidation (PCO) techniques for reduction of indoor air pollutants to assess feasibility for their application in air-tight zero-carbon housing. Due to emissions from building materials, such as coatings and wood-based materials on walls, ceiling and floors, as well as other furnishing materials such as new floor covering, there will always be high concentrations of volatile organic compounds (VOCs) in the indoor air of a newly completed building, especially air-tight homes. The concentrations could be reduced by the use of low emission products; however, PCO could further reduce the risk of emissions of these VOCs including formaldehyde. The use of PCO could also reduce risks caused by other indoor pollutions such as NOx, CO, CO2, moisture and microbes. The mechanism and applications of PCO reactors such as titania incorporated onto material surfaces of various built environments (roads, building façade and interior); and in HVAC systems for maintenance of indoor environmental quality, especially indoor air quality (IAQ) are discussed in the review as well as discussion on performance. The effects of temperature and moisture and possible toxic effects of PCO on environment are also included for consideration.

Primitive environment control for preservation of pit relics in archeology museums of China.

Immovable historical relics in some archeology museums of China suffer deterioration due to their improper preservation environment. The existing environmental control systems used in archeology museums are often designed for the amenities of visitors, and these manipulated environments are often inappropriate for the conservation of abiotic relics. This paper points out that the large open space of the existing archeology museum could be a cause of deterioration of the relics from the point of view of indoor air convective flow. The paper illustrates the need to introduce a local pit environmental control, which could reintegrate a pit primitive environment for the preservation of the historical relics by using an air curtain system, orientated to isolate the unearthed relics, semiexposed in pits to the large gallery open space of the exhibition hall.

China’s Building Energy Efficiency Targets: Challenges or Opportunities?

Climate change and global warming are important issues of our time, which have been dominating governments’ strategies, policies, building codes and standards and also research funding of university institutions all over the world. The United Nations Framework Convention on Climate Change (UNFCCC) and its Kyoto Protocol has established a basis of an agreement to cut CO2 emissions to alleviate the adverse effects of global warming [1]. China’s double digits economic growth for the past two decades had resulted in a rapid rise of CO2 emissions and other atmospheric pollution of urban cities. Although China’s CO2 emissions are still low on a per capita basis, China has already become the largest producer of CO2 emissions in the world. In 2007, China exceeded the carbon emissions of USA, with emissions of more than 6Gt [2]. In 2011, China became the largest contributor to the global increase of carbon emissions, rising by 0.72Gt, or 9.3%, primarily due to higher coal consumption [3]. In order to reduce global emissions so as to hold the increase in global temperature below 28C, the Chinese government pledged a 40–45% reduction in national carbon intensity from 2005 levels by 2020 at the Copenhagen Summit which has formed part of the Copenhagen Accord, 2009 [4]. To realize the above goal, China’s 11th Five-Year Plan set a target to decrease the overall energy intensity of the economy (energy consumption per unit of GDP) by 20% [5]. The 12th Five-Year Plan adopted by the Chinese government in March 2011 pays considerable attention to energy and climate change and establishes a new set of targets for 2011-2015 [6], which include:

Desiccation cracking of earthen sites in archaeology museum – A viewpoint of chemical potential difference of water content

Unearthed relics and earthen sites are historical evidence of our cultural heritage. Many of them are referred to as immobile cultural relics since both the relics-in-itself and their surroundings are our historic heritage of past emperor’s burial with significant historical importance such that they cannot be moved into indoor-display museums. Researchers have studied the specific environmental specifications to establish the desired steady temperature, humidity and air quality for collections and visitors in indoor-display museums. However, due to the unique exhibition characteristics, the conservation of earthen sites is still a challenge to environmental scientists and technologists, and how to effectively protect these ancient sites has been a major concern globally. Archaeology museum is developing advanced techniques to prevent weathering of relics caused by the sun, wind and rain. The in-situ relics in archaeology museum are far from being well preserved because of the lack of understanding of site conservation and the impact of indoor micro-climatic conditions. Many of them are suffering deteriorations or even ruins due to improper preservation environment adopted for maintenance of relics. Among the hazards that unearthed relics are facing with, desiccation cracking is the most common and problematic. The drying layer of the earthen site in the Banpo museum (Xi’an, China) is thicker than 0.4m (see Figure 1(a)). The same phenomena are also found in the Emperor Qin’s Terra-Cotta Warriors and Horses Museum (see Figure 1(b)), the water content of the earthen site decreased from 15% to 22% in 1994 when it was excavated to less than 5% now, such that serous shrinkage and cracking occurred on the surface of the site. To upgrade the conservation of the relics in archaeology museums, great efforts have been made in recent years, e.g. maintenance of a high relative humidity (RH) and space division in the exhibiting hall have been implemented in archaeology museum as a part of the preservation regime. The underground exhibiting hall of Hanyangling Museum (Xi’an, China) is such a modern archaeology museum (see Figure 1(c)). It exhibits partially exposed pits containing pottery figurines in the co-burial grave of the fourth Emperor (188–141 B.C.) and Queen of Han Dynasty, China. The enclosed space for relics’ domain is being maintained at about 24 C in summer and 16 C in the winter. Moreover, the RH has been maintained at a level higher than 95% to prevent the drying of unearthed relics and sites. However, the water content of the earthen site in the exhibiting hall still decreased from over 15% when it was excavated in 2006 to around 4% in 2009. In addition to the desiccation cracking, gypsum was found to deposit on the surface of relics due to the transport mechanism by which the carbonates were diffused and migrated with moisture across the air-relic-topsoil complex interfaces. The carbonates would react with the penetrating SO2 from the ambient atmosphere to form sulphates (see Figure 1(d)). The reason why desiccation cracking occurs in high humidity environment is not entirely clear. The conservation protocol, i.e. space division and maintaining a high RH as a preservation regime, has been considered by archaeologists as an approved practice and therefore the protocol was applied to new archaeology museums; however, cracking still persists in the terracotta relics and earthen sites. The desiccation cracking of unearthed relics and excavated sites in these archaeology museums seems to be a spontaneous process even though the RH of the atmospheric environment was at approximately the ceiling value (100%). In order to clarify the mechanism of moisture migration behind the desiccation cracking phenomenon and to verify whether a high RH is adequate to prevent the desiccation cracking of unearthed in-situ relics, the chemical potential analysis

Holistic Healthy Building for Human Habitat

Welcome to this Special Issue of Indoor and Built Environment. This Special Issue of journal papers is based on the advanced research studies that had been carried out by the Center for Sustainable Healthy Buildings (CSHeB) in Korea. The 20 papers in this Special Issue of Indoor and Built Environment were selected from a symposium presentation held on 27 May 2010 in Seoul, South Korea. These papers were further developed and peer reviewed by experts. International experts in Indoor Air Quality, Architecture, Environmental Toxicology and Building Services were also invited to contribute review and original research papers for this Special Issue. The International Society of the Built Environment (ISBE) is proud to be associated with this Special Issue and recommend you to study the papers presented. ISBE shares the same missions and beliefs with the CSHeB of Korea. We hope by our disseminations, we may contribute to the further advancement of innovative technologies for sustainable built environments; better designs that will improve health and well-being for everyone and an influence on policies and planning for sustainable development of Healthy Buildings for all cultures and nationalities. The main focus of this special issue of papers was the consideration of human aspects of built environments and how healthy environment can be achieved within architecture, to satisfy the occupants’ requirements for comfort, environmental quality and minimisation of environmental harm that could affect the health and well-being of people living and working in the environment. This Special Issue is of interest to broad interdisciplinary readers including academics, practitioners, and consultants. The CSHeB has become one of the leading research organisations in all the subjects concerning the built environment, emphasising the need for interdisciplinary research into architectural, medical, psychological, physiological, social and environmental aspects of healthy buildings. Progress has been made in understanding the need for social integration, design, construction, maintenance and occupants’ requirements for development of sustainable and healthy buildings. A number of reports and studies have been published providing the latest ‘‘state-of-the-art’’ dissemination of research relating to lighting, ventilation, social environment, indoor air quality, acoustics, thermal comfort, moisture and structure for the built environment. Sustainable development and sustainable buildings are important part of architecture and governments’ guidelines and building regulations in many countries of the world. Although the focus is on the building development, there is a need to consider the wider application of the building and the impact on the holistic health of the community regarding the social, economic and environmental implication of any build development to serve not just the physical need of accommodation, but the social, psychological and physiological needs of the intended occupants. A sustainable built environment should also be a healthy and happy environment for a healthy community of occupants and would not pose risks to people due to dampness, emissions from building materials, proliferation of moulds, noise generation and glare. There is also the need for the sufficient provision of sustainable transport infrastructure, education, training, leisure and play facilities as well as medical care for the built community, which should feel safe and secure from