基于室内空气品质的需求控制通风研究

本文研究的基于室内空气品质的需求控制通风，用CO2浓度作为室内人员相关污染物的控制指标，以TVOC作为室内建筑相关污染物的控制指标，从而容许在室内人员改变或建筑相关污染物浓度改变时调节入室新风量，实现了节能与提高室内空气品质的统一。文中对该方法理论和实验研究做了简要介绍。     

民用建筑中央空调系统的污染对室内空气品质(IAQ)的影响和控制措施

文章分析了空调系统的污染对室内IAQ(Indoors Air Quality)的影响程度,指出随着其它污染源被控制,其影响将更加突出;分析了空调系统各部件污染的成因,以及这些污染对IAQ的影响。根据国内外相关文献,结合空调系统设计运行情况和工作实践,提出防止空调系统污染的措施。     

厨房烟气对室内空气品质的影响及其改善方法

厨房烟气主要由烹调油烟和燃料燃烧产物组成,两者都对人体健康产生极大的危害。厨房烟气现有的改善方法分为烟气净化和厨房通风两大类,它们分别有着不同的实现方法和作用。最后,根据厨房烟气产生的原因,指出了应主要从控制油烟污染源、提高厨房烟气排放能力和加强厨房烟气净化能力等三个方面来改善厨房烟气对室内环境的影响。     

HVAC系统对室内空气品质的影响及改进建议

本文首先详细介绍了暖通空调系统对室内空气品质的作用,然后具体分析了暖通空调系统各部分对室内空气品质的影响,最后,综合多项工程经验提出了改进暖通空调系统对室内空气品质影响的几点建议。     

Effect of door opening on the performance of displacement ventilation in a typical office building

The purpose of this paper is to investigate, using a validated computational fluid dynamics simulation, the effect of the position of doors on performance of the displacement ventilation system. The results are reported in terms of thermal comfort and indoor air quality. The study focuses on a typical Hong Kong office under local thermal and boundary conditions. It was found that the presence of large heat sources such as from a window can cause the lateral movement of airflow, disrupting the convection effect which the displacement ventilation system relies on. Doors can create this situation when they are opened by changing the thermal boundary conditions of indoor spaces. The designer should be made aware of this possibility and make appropriate design decisions to accommodate for this fact.     

Effect of internal partitions on the performance of under floor air supply ventilation in a typical office environment

This paper presents a case to investigate the effect of partitions in an office on the performance of under floor air supply ventilation system via computational fluid dynamics. The assessment is in terms of thermal comfort and indoor air quality with the use of a validated computer model. The results indicate that the partitions may significantly affect airflow and performance of a under floor air supply ventilation system. In particular, the presence of a gap above the partition wall is able to improve air distribution owing to less air re-circulation in the upper zone. Its effect on thermal comfort and indoor air quality indicators are evaluated.     

空调系统设计对病态建筑综合症的影响与对策

针对空调建筑中大量出现的病态建筑综合症，从参数设计，新、回、排风设计、空调方式以及气流组织等方面，阐述了改善室内空气品质的空调系统设计方法和设计理念。     

Simulation of VOC emissions from building materials by using the state-space method

There are many mass-transfer models for predicting VOC emissions from building materials described in the literature. In these models, the volatile organic compound (VOC) emission rate and its concentration in a chamber or a room are usually obtained by analytical method or numerical method. Although these methods demonstrate some salient features, they also have some flaws, e.g., for analytical method the solutions of both room or chamber VOC concentration and building material VOC emission rate are constituted of the sum of an infinite series, in which additional computation for finding roots to a transcendental function is necessary, but sometimes quite complicated. Besides, when it is applied in complex cases such as multilayer emission with internal reaction, the solution is very difficult to get; for conventional numerical methods such as finite difference method, discrete treatment of both time and space may cause calculation errors. Considering that, the state-space method widely used in modern automation control field and the heat transfer field is applied to simulate VOC emissions from building materials. It assumes that a slab of building material is composed of a number of finite layers, in each of which the instantaneous VOC concentration is homogenous during the entire process of emission, while the time is kept continuous. Based on this assumption we can predict both the VOC emissions rate and the concentrations of VOCs in the air of a chamber or room. The method is generally applied to simulate VOC emissions from arbitrary layers of building materials, and the solution is explicit and simple. What's more, the method can be applied to the cases where a reaction producing/removing VOC in building materials exists. For some specific cases the method is validated using the experimental data and the analytical solutions in the literature. The method provides a simple but powerful tool for simulating VOC emissions from building materials, which is especially useful in developing indoor air quality (IAQ) simulation software.     

Stratum ventilation – A potential solution to elevated indoor temperatures

There is worldwide plea to reduce carbon dioxide emission. In response to such a call, several governments in East Asia recently have required to adopt higher room temperatures in summer. To promote such an idea, the public need to be convinced that such practice would not sacrifice indoor environmental quality, especially thermal comfort of the occupants. To implement such a measure, suitable ventilation system(s) to work under the unconventional conditions should be identified.     

Field measurements of indoor air pollutant concentrations on two new ships

Indoor air quality (IAQ) on ships is important for the passengers’ comfort and the crew’s work efficiency, despite ships not being as common as vehicles and airplanes. The builders and operators need to be aware of the importance and present status of IAQ, but sufficient data and information are not available. In this study, we measured the pollutant concentrations on two different kinds of newly launched ships: a passenger ship and a chemical cargo ship. Although higher than in the passenger ship, the concentrations of most volatile organic compounds (VOCs) and formaldehyde in the cargo ship were lower than the recommended standards and acceptable with a few exceptions. The high CO and CO₂ concentrations in the kitchen, engine room, and engine control room were generally attributed to combustion sources. Overall, the IAQ of the cargo ship was worse than that of the passenger ship, and the concentrations of some pollutants surpassed the international criteria. For the passenger ship, the variation of IAQ was also investigated after 17 months. The observed data showed some differences in concentration variation according to the types of pollutants. To improve IAQ on ships, more data need to be collected and minimum requirements suggested.     

Control tuning of a simplified VAV system: Methodology and impact on energy consumption and IAQ

Nowadays, with the improvement of living standards, air-conditioning systems have been widely used causing more health problems linked to air-conditioning systems and indoor air quality. When an air handling unit is designed for a conference room, its variable use demands an outdoor air rate control in particular to optimize energy consumption of the new air heating/cooling. Based on an experimental site, the present work shows how to combine air quality and the improvement of energy consumption thanks to a way to define a control strategy. The control problem considered here is the management of air quality associated to a control of the outdoor air rates. A review of classical tuning methods is led in order to select suitable ones. Thus, a linearization of the phenomena must be done to border the system expression in tuning methods. Several classical methods are studied and the family model is chosen: monovariable and multivariable applications are brought to fruition. Simulations and applications permit to enhance energy consumption through the choice of a strict way to tune such control equipments.     

Modeling particle fate in ventilation system—Part II: Case study

In this paper the particle filter group model, which was presented in the first part of this series of study, is employed to predict particle fate in a typical ventilation system. The model simultaneously takes into account the interactions between particle transport in ventilation ducts and rooms and particle spatial distribution. It has been proven that an entire ventilation system, including filters, ducts and rooms, can be regarded as a serial of filters in steady-state cases, hence the name “particle filter group model”. With this model, the particle concentration and quantity of deposited particles in each part of the ventilation system can be easily calculated.     

Detection of human effluents by a MOS gas sensor in correlation to VOC quantification by GC/MS

Due to increasing interest in indoor air quality (IAQ) monitoring for demand controlled ventilation (DCV) aiming at improved perceived air quality, health, energy and cost saving, the objective of this study has been the development of a sensor module based on a single microelectromechanical-system (MEMS) metal oxide semiconductor (MOS) gas sensor for IAQ monitoring as close as possible to the human sensory impression in indoor environments. Based on the results of a statistical evaluation on human induced volatile organic compounds (VOCs) in the ambient air of indoor environments correlating with human presence and perceived air quality, the performance of differently doped SnO₂ thick film gas sensor materials has been investigated in laboratory and by means of field tests in order to find the most promising sensor material for IAQ monitoring based on the detection of changes of human induced VOCs in indoor air. Implementation of an empirical evaluation algorithm reversing proportionality of anthropogenic CO₂ production and other bio-effluent generation allows prediction of CO₂ equivalent units. Analytical instrumentation and reference sensors served to evaluate the effectiveness of the developed sensor module in real-life.     

建筑热环境和室内空气质量综合模拟软件介绍

本文首先阐述了研究室内空气品质(IAQ)问题的重要性和必要性,介绍了目前已有的与室内空气品质相关的模拟软件。而后,基于"室内健康、环保和节能"的理念,提出了新的室内污染物浓度动态网络模拟分析与评估软件(DeST-IAQ)的理论框架,主要是将自然通风通路和机械通风网络集成,构成建筑通风和污染物传播的多区域网络模型,实现建筑通风和污染物浓度的联合动态预测,解决建筑通风模型、热模型和IAQ模型统一模拟的难题,满足建筑物能耗和室内空气品质预测的双重需求。该软件已在一些实际案例中得到了初步应用,其实用性具有较好的实验验证。     

Indoor air quality audit implementation in a hotel building in Portugal

Hotels are designed to provide high levels of comfort for guests; however, frequent complaints related to uncomfortable thermal environment and inadequate indoor air quality (IAQ) appear. On the other hand, there is little research concerning IAQ audits of hotels up to now.     

Air flow rates and energy saving potential in schools with demand-controlled displacement ventilation

Demand control is particularly energy efficient and reliable when combined with displacement ventilation (DCDV). In order to investigate how much DCDV in practice reduce the ventilation air volumes and the energy demand, two Norwegian schools with CO₂-sensor based demand controlled displacement ventilation (DCDV-CO₂), Jaer School and Mediå School, are analysed and compared with traditional constant air volume (CAV) mixing ventilation. During daytime operation with normal school activity, DCDV-CO₂ reduces the ventilation air volume by 65–75% in both schools compared to CAV. For Mediå School, both the airflow rates and the energy performance were analysed through measurements and use of a detailed, calibrated simulation model. The analysis period was 11–17 November, 2002. It was found that during this week, DCDV-CO₂ daytime operation weekdays reduce the total heating energy demand by 21%, the amount of unrecovered heat in the exhaust ventilation air by 54%, and the average airflow rate by 50%. Presuming constant fan efficiency it was also found that DCDV-CO₂ daytime operation weekdays reduce the fan energy consumption by 87% the analysed week.     

Modeling particle fate in ventilation system—Part I: Model development

Aerosol particles are regarded as one of the most significant pollutants in the indoor environment. These particles can travel through ventilation systems, thus impacting indoor air pollution. Accurate modeling and prediction of aerosol particle transport in ventilation systems is therefore a key component of indoor particle pollution. Since recycled air takes particles into the ventilation system again, it can be challenging to calculate the particle concentration in each part of the system. This study theoretically and experimentally proves that the entire ventilation system, including filters, ventilation ducts and ventilation rooms, can be regarded as a serial of filters in steady-state cases. We call this the particle filter group model. Equations are presented to calculate the particle concentration in each component of normal kinds of mechanical ventilation systems. With this model, the particle concentration and deposited particle quantity in each part of the ventilation system can be easily calculated. This model may help to control indoor particle pollution and guide the cleaning of ventilation ducts and filters.     

Experimental validation of a computational fluid dynamics model for IAQ applications in ice rink arenas

Many ice rink arenas have ice resurfacing equipment that uses fossil fuel as power. The combustion byproducts are a major source of contamination. Ventilation along with other pollution source control measures is the most widely applied strategy to lower the contaminant level below the threshold limit and maintain acceptable indoor air quality (IAQ). A computational fluid dynamics (CFD) model has been developed and used to predict the contaminant concentrations, air velocity, and air temperature distributions in ice rinks. The numerical results agree reasonably with the corresponding experimental data for both steady-state and transient conditions. The CFD model is a useful and inexpensive tool to investigate ventilation parameters, such as air distribution methods, ventilation effectiveness, air exchange rates, and various ventilation control strategies.     

Determination of Exposure-Response Relationships for Emissions from Building Products

Abstract Building products have been shown to affect the perceived indoor air quality in buildings. Consequently, there is a need for characterizing the emissions from building products in sensory terms to evaluate their impact on the perceived air quality. Determining the exposure-response relationship between concentration of the emission from a building product and human response is recommended. A practical method is proposed based on an air-dilution system connected to the exhaust of a ventilated small-scale test chamber. The method was used to determine the exposure-response relationships for eight building products. For each building product, samples were placed in a test chamber. A typical room was used as a reference to calculate a building-realistic area-specific ventilation rate in the test chamber. A sensory panel assessed the immediate acceptability of polluted air at four different concentrations 3, 10 and 29 days after samples of the building products were placed in the test chambers. The exposure-response relationships show that the impact of dilution of polluted air on the perceived air quality varies between building products. For some building products it may only be possible in practice to improve the perceived air quality marginally by increasing dilution. The results of the present study suggest that for such building products, source control is recommended as the remedy for poor indoor air quality, rather than an increase of the ventilation rate.