International Journal on Architectural Science, Volume 4, Number 2, p.60-72, 2003

STUDY ON INDOOR ENVIRONMENT IN AIR-CONDITIONED TRAINS Huanxin Chen*, Suyi Huang* and Peizhi Yang# *

#

School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan, Hubei Province, China School of Civil and Architectural Engineering, Central South University, Changsha, Hunan Province, China

(Received 13 September 2002; Accepted 18 February 2003)

ABSTRACT Indoor air quality (IAQ) is the problem that people increasingly pay attention to. With the development of Chinese railway undertaking, air-conditioned train is developing to the direction of higher speed and more comfortable. However, in China, people pay more attention to the temperature and the relative humidity in train compartments, but do not care for IAQ, so it leads to poor IAQ in train compartments. This paper has investigated IAQ in train compartments in the form of questionnaire, and analyzed the result in different types of train compartments, with different load factor, different outdoor environmental parameters, different train speed, and windows opened or not. At last, we come to the conclusion that fresh air is the main factor that affects indoor environment. We put forward some measures to improve indoor environment in train compartments.

1.

INTRODUCTION

IAQ is a hot topic which people pay attention to in recent years. Many investigations show that there are many complaints from occupants, and that it is very common to have low concentration pollutants existing in habitation. All the inquisitional results show that there are two reasons for poor IAQ: one is the incorrect design and operation of HVAC systems; and the other is the effect of pollutants [13]. An Arab oil embargo in 1973 triggered off an energy crisis worldwide, thus, a modern refrigerator would consume considerably less power than before. One of the measures of saving energy is to drop off fresh air. It saved a great amount of energy but at a cost, the air becomes stale as a result of the accumulation of pollutants such as CO2, CO, formaldehyde, volatile organic compound, dust, bacteria, etc. [4]. Air-conditioned train has the feature of big occupant density and highly closed compartments, so the IAQ becomes worse. As the main source of pollutant in compartment comes from the passengers, the primary pollutant is CO2. Assessment of IAQ is one of the important aspects in the study of IAQ. It contains subjective assessment and objective assessment. Objective assessment is the way to assess IAQ through monitoring indoor pollutant concentrations. Subjective assessment is through inquiring occupants, that is to say, we can apply people’s sense organ for describing and assessing indoor environment. In order to obtain much more

information and reliable data, we can apply the international assessment table to get a normative subjective assessment. At present, many scholars and experts begin to attend the study of IAQ in airtight traffic tools (for example, air-conditioned trains, automobiles, airplanes, etc.). Fromme et al. have found that CO is the main pollutant in car [5]. Conceicao et al. have used the method of tracer gas to obtain air exchange rate in the passenger compartment [6]. Haghighat et al. have studied thermal comfort and IAQ, and have come to the conclusion that the low level of humidity and high concentrations of carbon dioxide are the main reasons that lead to poor IAQ in airplanes [7]. In China, Sheng has discovered that people who work in there always get sick building syndrome by investigating four typical official buildings in Shanghai, and has established indoor air quality assessments from subjective and objective ways by monitoring of the indoor pollutants [8-9]. Li has founded a way to calculate indoor temperature and relative humidity. It can be applied to assess the indoor PMV and PPD [10]. Based on the variation of environmental parameters, Zhao has put forward a regulative strategy that is used to improve indoor environment [11]. Though realizing the importance and imminence of solving the problem of IAQ in building, people pay little attention to the problem occurred in airconditioned trains. In recent years, incidents that passengers accuse Railway Ministry of poor IAQ are often occurring. The incident of the delay in one of the railway lines in 1996 led to over 90

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people feeling uncomfortable and the normal operation of the railway line was disturbed for almost half a day [12-14]. At present, there are few studies about IAQ in train compartments in China. The technician should pay more attention to it. In this paper, we have investigated IAQ in airconditioned trains in the form of questionnaire, and obtained valuable data. We have analyzed these factors which affect the IAQ, and put forward the ways to improve IAQ, by contrasting different types of train compartments, different load factor, windows opened or not, different outdoor environmental parameters and different train speed.

2.

THE PRESENT SITUATION OF AIRCONDITIONED TRAINS IN CHINA

In China, people always choose air-conditioned train as traffic tool. Fig. 2 shows the number of passengers transported by trains in 2000 [16], from which we can realize that the peak of Chinese railway passenger transport concentrates on the periods from July to August, and from January to February because the two periods include summer vacation and Spring Festival. There are three types of train compartments in China: hard seats, hard sleeper and soft sleeper, and the fixed numbers of persons are 118, 66 and 36 respectively. For the ventilation system of the train compartments in China, we still adopt the fixed air quantity system. That is, the quantity of fresh air applied into train compartments is equal to a constant, it does not vary with the number of passengers and other reasons. The environment of the train compartment has strong effect on passengers’ health because railway transportation has features of long distance, long time and high passenger density. However, IAQ is the most important factor affecting passengers’ health. Good IAQ can make passengers comfortable, otherwise, make passengers stifling, or even lead to disease.

No. of air-conditioning units

At present, air-conditioned train is an important means of transportation. With the development of living level and tourism, people’s demand for IAQ is also increasing. In order to improve comfort, many expresses and sight-seeing trains are replaced by air-conditioned trains, and part of local trains are installed with air-conditioning unit. According to statistics, there were 34,000 trains in China in 1998, among which, one-third were air-conditioned train; moreover the percentage is increasing [15].

Fig. 1 shows the number of air-conditioning units manufactured from 1994 to 2000.

Year

No. of passengers (ten thousand)

Fig. 1: Number of air-conditioning units manufactured in China

Month

Fig. 2: Number of passengers transported by air-conditioned trains in China in 2000

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Due to the contradiction between the capacity of air-conditioned trains and the demand of passengers in China, overloading often exists. Because many passengers have poor consciousness about environmental protection, the phenomenon of smoking in train compartment is ever-present. A great deal of decorative materials in air-conditioned trains release volatile organic compounds. High passenger density, complicated personnel, pollutants which come from passengers’ goods, and floating dust which comes from machinery’s operation lead to poor IAQ in train compartments. Table 1 lists the main pollutants in air-conditioned trains [17]. Passengers who stay in that environment for a long time will have symptoms such as stung of eyes and throat, stuffy nose, headache, dizzy, sickness, chest tightly, tined, skin dry, doze off, fidget, etc. In order to improve indoor environment of train compartments and strengthen the competition of railway transport, we must pay more attention to the study of IAQ in air-conditioned trains. In this paper, we analyzed the factors that affect IAQ, and put forward measures to improve the IAQ.

3.

INVESTIGATION AND STUDY

In the initial stage, people thought that IAQ is equal to the guidelines of all kinds of air pollutants, but many investigations showed that occupants still feel that IAQ is bad and serious though objectively environmental guidelines meet the demand of health standard. It is because hundreds of lowconcentration organic pollutants have a synthetically effect on people. From above, we realized that acceptable IAQ should shift gradually from objective assessment to subjective assessment, and the subjective assessment should become the important basis of IAQ assessment.

3.1 Formulation of Questionnaire Subjective Assessment

for

The influence from the stimulation of sense can be defined by the symptom of self-sense and the degree of unease. Due to the expression of selfsense is not accurate, and to prevent error caused by different edition of assessment standard, it is

necessary to formulate a standard which can reflect different degree of unease. So numerical values should be used to express the different degree of unease. With these numbers, we can make things convenient for statistics. This set of numerical values is called rating scale. The definition can distinguish slightly sensible intensity. The ratings of sense which people can feel obviously have seven grades. We often applied five grades for the assessment of IAQ (This way is called equal distribution for grade). Subjective assessment also includes the investigation of background that contains the personal data because the self-sense in the same environment is different to sex, age and occupation. We designed a questionnaire aiming at train compartments. The questionnaire is showed in Appendix 1.

3.2 Statistics and Analysis of Subjective Assessment 3.2.1 Overall analysis of data We made investigations (ten times) about IAQ in train compartments by students who went on business from May to June 2001. The area of investigation involved the following regions: from Changsha to Huhan (4 times), from Changsha to Guangzhou (2 times), from Beijing to Shijiazhuang (2 times), from Shijiazhuang to Zhengzhou (2 times). Fig. 3 shows these regions. In these investigations, we delivered 1200 copies of questionnaires in total, 640 in hard seat, 350 in hard sleeper and 210 in soft sleeper compartments respectively. We got back 960 questionnaires in total, with 540, 240 and 180 from these three types of compartments respectively. Table 2 and Table 3 show the statistical results. The passenger’s symptoms shown in Table 2 indicate that the main symptoms in train compartments are chest tightly, dizzy, headache and sick. It is because there is inadequate fresh air and high concentrations of CO2 and other pollutants. If enough fresh air is provided to dilute stale air, the IAQ in train compartments will be improved [18].

Table 1: The main pollutants in air-conditioned trains Pollutants CO2 CO Stench Floating dust Volatile organic compounds

Source of pollution Burning of fuel in dinning room, breath of passengers Burning of fuel in dinning room, smoking Body’s stench, smoking, produced by addled foodstuff Burning of fuel in dinning room, smoking, and cleaning Paint, furniture

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c Guangzhou d Changsha e Wuhan f Zhengzhou g Shijiazhuang h Beijing i Haikou j Taibei k Shanghai

l Haerbin (11) Wulumuqi (12) Huhehaote (13) Xi’an (14) Chengdu (15) Lasa

Fig. 3: The investigated line and main station Table 2: The degree of symptoms in three types of train compartments (%) Types of compartments Headache Dizzy Throat dry and tongue Tired Symptom of cold Sick Chest tightly Skin dry

Hard seats 35.2 35.2 37 27.8 22.2 51.9 51.9 27.8

Hard sleeper 20.7 20.7 17.4 13.8 13.8 13.8 20.7 13.8

Soft sleeper 11.1 11.1 16.7 5.6 5.6 5.6 22.2 11.1

Table 3: The rate of dissatisfaction to the environment (%) Types of compartments Wind quality Temperature Humidity Odor IAQ

Hard seats 44.4 59.3 59.3 59.3 59.3

From Table 3, we can find that most passengers are not satisfied with the indoor environment of train compartments. The dissatisfactory degree in hard seats, hard sleeper and soft sleeper is 59.3%, 37.9% and 22.2% respectively, and they all surpass the guideline of 20%. According to ASHRAE 62-1989 [19], the IAQ in air-conditioned trains is disqualified. 3.2.2 The contrast of three types of train compartments In order to contrast the inquisitional result of the three types of compartments, we transform the data in Table 2 and Table 3 into Fig. 4 and Fig. 5.

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Hard sleeper 31.0 51.7 31.0 34.5 37.9

Soft sleeper 22.2 22.2 22.2 11.1 22.2

From Fig. 4 and Fig. 5, we can find a rule: in these three types of train compartments, passengers in hard seats had the most obvious symptoms, followed by hard sleeper, and then soft sleeper. The rate of dissatisfaction is highest in hard seats, followed by hard sleeper, and then soft sleeper. Through analyzing these data, we find that though IAQ of these three types of compartments are all poor, IAQ of soft sleeper is the best relatively, followed by hard sleeper, and then hard seats. Actually, it is related to the quantity of fresh air. Hard seat’s fixed number of persons is the largest, what is more, hard seats are often overloaded. All these lead to the decrease of fresh air quantity offered to passengers, accordingly, IAQ is worst in hard seats.

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60.0 % 50.0 % 40.0 % 30.0 % 20.0 % 10.0 % 0.0 %

headache

dizzy

throat dry and tongue dry

tired

soft sleeper

symptom of cold hard sleeper

sick

chest tightly

skin dry

hard seats

Fig. 4: The degree of symptoms in three types of train compartments

60.0 % 40.0 % 20.0 % 0.0 %

wind quality

temperature

humidity

soft sleeper

odor

hard sleeper

IAQ

hard seats

Fig. 5: The rate of dissatisfaction in three types of train compartments 3.2.3 The contrast of different load factors In China, it exists overload in railway for the contradiction between capacity and the demand of passengers. Generally, the phenomenon is more serious in the compartments of hard seats than the other two types of compartments. Fig. 6 and Fig. 7 show the inquisitional result at different load factors. It indicates that the degree of discomfort increases with the increase of load factor. In China, the design of ventilation and air conditioning for air-conditioned trains is relied on the fixed number of persons to get the fixed quantity of fresh air. During the operation of the air-conditioned trains, the supply of fresh air would not change with the change in the number of passengers in the train compartments. This has drawbacks. If fixed supply of fresh air is kept during operation, we will meet two kinds of conditions: first, if the number of passengers is smaller than the fixed number of persons, the applied quantity of fresh air is more than needed, consequently, it will waste energy; on the other hand, if the number of passengers is more than the

fixed number of persons, it will lead to poor IAQ because of inadequate quantity of fresh air. 3.2.4 The contrast between opened window and closed window When IAQ is poor in the train compartments, passengers would often open the windows for getting more fresh air to improve IAQ. Hence, we chose two compartments of hard seats for contrast. The windows were opened in one compartment, and closed in the other one. Then, we contrasted these two groups of data. The results of contrast are shown in Fig. 8 and Fig. 9. We set the compartment of which windows were not open as compartment A and the other one as compartment B. By contrasting, we can make the following conclusions: a.

The index level of compartment A is higher than that of compartment B in the degree of symptom and dissatisfaction (excluding temperature). Because the windows were

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indoor temperature. Outdoor hot air rushes into compartment B through the open windows that lead to the rise of indoor temperature, so passengers in compartment B feel uncomfortable with the indoor temperature.

open in compartment B, and outdoor air could directly rush into the compartment, the IAQ in the compartment is better. However, it is at a cost of energy consumption. b.

The passengers in compartment B are more dissatisfied than in compartment A with the 60.0 % 50.0 % 40.0 % 30.0 % 20.0 % 10.0 % 0.0 %

headache

dizzy

throat dry and tongue dry

tired

80%

symptom of cold 100%

sick

chest tightly

skin dry

120%

Fig. 6: The degree of symptoms at different load factors

50.0 % 40.0 % 30.0 % 20.0 % 10.0 % 0.0 %

wind quality

temperature

humidity

80%

100%

odor

IAQ

120%

Fig. 7: The rate of dissatisfaction at different load factor 60.0 % 50.0 % 40.0 % 30.0 % 20.0 % 10.0 % 0.0 %

headache

dizzy

symptom of cold closed window

sick

chest tightly

skin dry

opened window

Fig. 8: The contrast of degree to symptoms between opened window and closed window

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60.0 % 40.0 % 20.0 % 0.0 %

wind quality

temperature closed window

humidity

odor

IAQ

opened window

Fig. 9: The contrast of rate of dissatisfaction between closed window and opened window calculative temperature is subzero 14 oC in winter.

3.2.5 The effect of outdoor environmental parameters on IAQ

b.

During the investigation, we found that outdoor environmental parameters have effect on IAQ in train compartments. China with a vast expanse has various climates, from north to south crossing over the tropics, temperate zone, and frigid zone. For example, presume outdoor temperature is 35oC, usually, the relative humidity is 56% in Beijing, but 85% in Guangzhou. Table 4 lists some environmental parameters in some cities in China. It shows that there are enormous differences between the southern part and the northern part of China. When the air-conditioned train is crossing over these zones, the fluctuation of outdoor temperature is great. While the air-conditioned train is running in the northern part, passengers feel hot and dry, and while moving in the southern part, passengers feel muggy because sweat is uneasy to diffuse in hot and moist compartments.

The parameters are unsuitable because it will lead to great deviation between actually operating mode and designate operating mode in air-conditioning. Let us take air-conditioned train as an entity to analyze the balance of quantity of heat. In summer, if outdoor temperature is lower than the designate temperature, it will lead to the decrease of load and indoor temperature; and if outdoor temperature is higher than the designate temperature, it will lead to the increase of load and indoor temperature. It proves that outdoor environmental parameters influence IAQ.

Fig. 10 and Fig. 11 show the results of questionnaire. Designate parameters of airconditioned trains are obtained from the standard of Railway Ministry of People’s Republic of China TB1951-87. It provides the calculative parameters of outdoor air in the main stem of the southern part of China for air-conditioned trains, as following [20]: a.

calculative temperature is 35oC, relative humidity is 60% in summer

3.2.6 The effect of train speed on IAQ We investigated two air-conditioned trains with train speed of 80 and 120 kmh-1 respectively. Fig. 12 and Fig. 13 show the result of the contrast. We find that IAQ in the air-conditioned train with faster speed is more uncomfortable than that in the air-conditioned train with slower speed. It is because that train speed affects the operation of the condensers installed on top of the air-conditioned train. When the air-conditioned train is running with higher speed, the wind quantity supplied to the condensers cannot meet the demand of normal operation of air-conditioning, and it results in the decline of cooling competence.

Table 4: Meteorologic data for some cities in China Cities Guangzhou Changsha Wuhan Zhengzhou Shijiazhuang Beijing

Mean days for its highest temperature ≥ 35oC in a year (day) 5.2 30 21 20.8 16.2 7

Average temperature in hottest month (oC)

Dry bulb temperature for air-conditioning in summer (oC)

26.4 29.3 28.8 27.3 26.5 25.8

33.5 35.8 35.2 35.6 35.1 33.2

Average temperature in airconditioned days in summer (oC) 30.1 32.0 31.9 30.8 29.7 28.6

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50.0 % 40.0 % 30.0 % 20.0 % 10.0 % 0.0 % headache

dizzy

symptom of cold southern part of China northern part of China

sick

chest tightly

skin dry

Fig. 10: Contrast of the degree of symptoms between the southern part and the northern part of China

60.0 % 40.0 % 20.0 % 0.0 %

wind quality

temperature

humidity

odor

IAQ

southern part of China northern part of China

Fig. 11: Contrast of the rate of dissatisfaction between the southern part and the northern part of China

50.0 % 40.0 % 30.0 % 20.0 % 10.0 % 0.0 % headache

dizzy

symptom of cold 120 kmh-1

sick

chest tightly

skin dry

80 kmh-1

Fig. 12: Contrast of the degree of symptoms between the train speed of 120 kmh-1 and 80 kmh-1

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50.0 % 40.0 % 30.0 % 20.0 % 10.0 % 0.0 %

wind quality

temperature

humidity

120 kmh-1

odor

IAQ

80 kmh-1

Fig. 13: Contrast of the rate of dissatisfaction between the train speed of 120 kmh-1 and 80 kmh-1

EFFECT OF INDOOR ENVIRONMENTAL PARAMETERS ON THE RESULT OF THE INVESTIGATION

seats compartments is higher than in the other two types of compartments. It is resulted from higher temperature in hard seats compartments.

During the investigation, we measured the environmental parameters on the spot. We used the thermograph whose precision is one degree to measure the indoor temperature, and used the wet bulb thermograph to measure the indoor wet bulb temperature, through calculation to obtain the indoor relative humidity. In order to assure the precision, we used two thermographs to survey the temperature in the same compartment, and took the average value as the compartment’s indoor temperature. Table 5 shows the result.

When the air-conditioned train is running, according to the usual practice in China, the ratio of return air to fresh air fixed is 3. We can calculate the quantity of fresh air obtained by each passenger in different types of compartments. These figures shown in Table 6 are less than 8 Ls-1person-1 ruled by ASHRAE-99 [21]. What is more, quantity of fresh air offered to each passenger actually is smaller than that the designed value because of overload and irrational airflow organization. Actual quantity of fresh air offered to passenger is showed in Table 6 (these types of compartments have the same size of length 25 m, width 2.8 m and height 2.3 m).

4.

It indicates that the temperature in hard seats compartments is higher than the other types of compartments. The above analytical result indicates that the degree of symptoms in hard seats compartments is higher than that in the other two types. As a result, indoor temperature has quite an effect on IAQ.

We can reach the decision that passengers in soft sleeper compartment obtain most quantity of fresh air, but those in hard seats compartment obtain less. Moreover, the probability of passenger getting sick building syndrome in hard seats compartments is higher, and it is lowest in soft sleeper compartments. Hence, the principal factor that causes poor IAQ is inadequate quantity of fresh air.

Though there are slight differences in the relative humidity among these three types of compartments, the probability that passenger feels skin dry in hard Table 5: Indoor environmental parameters Types of compartment Hard seats Hard sleeper Soft sleeper

Dry bulb temperature (oC) 30.0 ~ 31.2 26.1 ~ 26.9 22.5 ~ 23.4

Wet bulb temperature (oC) 21 ~ 22.1 18.2 ~ 18.8 16 ~ 17.1

Relative humidity (%) 61 ~ 68 52 ~ 59 48 ~ 56

Table 6: Quantity of fresh air offered to passenger Types of compartment Hard seats Hard sleeper Soft sleeper

Quantity of fresh air (m3h-1) 1500 1000 7500

Fresh air supplied to passenger (Ls-1person-1) 3.54 4.21 5.79

Actual fresh air supplied to passenger (Ls-1person-1) 2.5 ~ 2.9 3.5 ~ 4.0 5.2 ~ 5.6

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5.

METHODS OF IMPROVING IAQ IN TRAIN COMPARTMENTS

5.1 Replacing Traditional Way of Design of Fresh Air Quantity ASHRAE 62R-1989 (1996 revised) introduces the following formula which calculates the quantity of fresh air to replace the method that uses CO2 as the pollution guideline [22]. DVR = RPPDD + RBAB

(1)

where DVR is the rate of ventilation for outdoor air (m3s-1); RP is the minimum quantity of fresh air required by each person (m3s-1per-1); PD is the quantity of people indoor (persons); D is coefficient; RB is the quantity of fresh air required by indoor unit area (m3s-1per-1); and AB is the indoor area (m2). The formula indicates that the quantity of fresh air is consisted of two parts: one is used to dilute pollutants produced by person, and the other is used to dilute pollutants produced by the environment. In the formula, only PD is variable, however, RP and RB are fixed by criterion. According to this method to control the quantity of fresh air, IAQ in train compartments will be improved.

5.4 Adjust the Quantity of Fresh Air according to the Concentration of CO2 With fixed quantity of fresh air, the concentration of CO2 fluctuates with the change of the quantity of passengers. It leads to poor IAQ. Hence, it is significant to adjust the quantity of fresh air to keep indoor air fresh. Document [24] involves the development of taking CO2 as a manipulative object in air-conditioned ventilation control system, and argues on the advantages of this method. In Hong Kong, the study about ventilation in airconditioned trains has taken CO2 as the key factor for IAQ [25]. By maintaining the concentration of CO2 in the train compartments at 1500 ppm [20], we can reach the aim of controlling fresh air. The method applied in air-conditioned trains has the following advantages: a.

CO2 is a kind of gas exhaled from passengers. CO2 concentration shows the dilute degree of gases that are sent out by passengers. In the inhabitancy where pollutants’ concentrations are low, if the concentration of CO2 is controlled at 1500 ppm, the other pollutants will also be controlled under guideline.

b.

If we set CO2 as the manipulative object, the quantity of fresh air will include not only from air-conditioning unit, but also from the entrance of the train compartments when the train arrived at the platform, hence the method will cut down energy consumption.

c.

As CO2 concentration’s inertia is big in airconditioned zone, the ability of antiinterference is better in the whole controlling system, and the controlling system is relatively steady.

5.2 Modification of Designate Parameters China is a country with a vast expanse and diversity in climate. Outdoor environmental parameters vary when the air-conditioned train traverses these regions. Hence, it is necessary to adjust the parameters. We suggest that China should be divided into regions, and that each region should have its own outdoor air parameters. When air-conditioned train runs in one region, air conditioning unit should be adjusted to make actual operating mode reconcile with designate operating mode, in the end, we can reach the aim of keeping indoor environmental parameters in the train compartments constantly.

5.3 Airflow Organization Airflow organization is the important factor that influences IAQ. Thermal Displacement Ventilation is a form of airflow organization by which can reach best air quality [23]. It supplies air to the work area from the ground floor. The thermal air pushed by the following supply air would rise, and then drawn by the top outlet. Thus, the air in the work area is always fresh. If possible, we could apply thermal displacement ventilation to airconditioned trains for improving the airflow organization in the compartments.

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5.5 Daily Maintenance It is important to maintain air-conditioning unit. If air-conditioning unit is not maintained well, it will not only be a source of pollution, but also block the flow of airflow. The ducts and air-conditioning unit need cleaning, meanwhile condensed water should be drained so quick to prevent the breeding of bacteria and fungus, and filter net for fresh air and return air should be washed or replaced periodically.

5.6 Strengthen Management to Passengers As the behaviors of passengers influence IAQ in train compartments, the environmental awareness of passengers should be improved. We should set strict rules to ban behaviors that will pollute IAQ such as smoking, spitting, etc. The execution of these rules depends on passengers and trainmen.

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6.

CONCLUSION

y

The result of the investigation indicates that passengers are not satisfied with IAQ in train compartments for the odors in compartments smell unpleasant, passengers who stay in this environment for some time will appear kinds of symptoms, such as headache, dizzy, sick, etc. For hard seats, hard sleeper and soft sleeper, the rates of dissatisfaction are 59.3%, 37.9 and 22.2% separately. Hence, it is necessary to improve IAQ.

y

The applied assessment criterion is based on ASHRAE standard, but ASHRAE standard is not fit for air-conditioned train exactly, let alone air-conditioned train in China. We should establish objective and subjective assessment criterion applied for airconditioned train as quick as possible, so that the technician has the criterion for designing, and operator for modulating air-conditioning unit.

y

When air-conditioned train is running, IAQ should be monitored, so that IAQ can be satisfied to passenger.

y

The study in this paper will benefit researcher’s need in air-conditioned train and improvement of IAQ in train compartments.

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2.

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7.

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11.

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12.

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13.

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14.

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19.

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20.

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21.

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rates:

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APPENDIX 1 A Survey on Indoor Air Quality in Air-Conditioned Train in China Part A General Personal Date 1. Sex

† Male

† Female

2. Age

† Below12

† 12 to 25

† 26 to 55

† Above 56

3. Occupation

† Worker † Student

† Peasant † Manger

† Serviceman † Technician

† Others

4. Period for staying in air-conditioned train this time: † Less than 2 hrs. † Between 2 to 10 hrs. † Between 10 to 24 hrs. † More than 24 hrs. 5. Compartment you seat in: † Hard seats compartment

† Hard compartment

† Soft compartment

6. Number of people in your compartment: † Less † Full † Over laden Part B Indoor Air Condition 1. Please circle, indicating degree, symptoms experienced in the compartment. Not at all a. b. c. d. e. f. g. h.

Headache Dizzy Throat dry and tongue Tired Symptom of cold Feel sick Chest tightly Skin dry

Very much 1 1 1 1 1 1 1 1

2 2 2 2 2 2 2 2

3 3 3 3 3 3 3 3

4 4 4 4 4 4 4 4

5 5 5 5 5 5 5 5

2. Environmental condition 2.1 How do you feel about the ambient air temperature in the compartments? † Cold † Cool † Neutral † Warm

† Hot

2.2 How do you feel about the compartment air humidity? † Too dry † Dry † Acceptable

† Humid

† Too humid

2.3 How do you feel about the compartment air quality? † Very stuffy † Stuffy † Acceptable

† Fresh

† Very fresh

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International Journal on Architectural Science

2.4 How do you feel about the odor? † Very satisfied † Satisfied

† Acceptable

2.5 How do you feel about the compartment wind quantity? † Very strong † Strong † Acceptable

† Dissatisfied

† Very dissatisfied

† Weak

† Very weak

3. Overall Performance 3.1 Do you feel satisfied with the environment conditions in the comportment? †Very satisfied † Satisfied † Acceptable † Dissatisfied † Very dissatisfied 3.2 Is there smoker in you compartment? † Yes † No 3.3 Do you think these symptoms are caused by indoor environment? † Yes † No 3.4 If you get other symptoms, or have some advice, please write down in the following blank.

3.5 Completion Date ____________ Thank you for your co-operation!

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