Indoor Air Design Parameters of Air Conditioners for Mold-Prevention and Antibacterial in Island Residential Buildings

International Journal of Environmental Research and Public Health

Article Indoor Air Design Parameters of Air Conditioners for Mold-Prevention and Antibacterial in Island Residential Buildings

Xueyan Zhang 1, Jingyi Liang 1, Beibei Wang 1, Yang Lv 1,* and Jingchao Xie 2 1 School of Civil Engineering, Dalian University of Technology, Dalian 116024, China; [email protected] (X.Z.); [email protected] (J.L.); [email protected] (B.W.) 2 School of Construction Engineering, Beijing University of Technology, Beijing 100000, China; [email protected] * Correspondence: [email protected]; Tel.: +86-1594-113-8175

Received: 31 August 2020; Accepted: 2 October 2020; Published: 7 October 2020

Abstract: The climate characteristics of the islands in the Nansha Islands of China are a typical marine climate including high temperature, high relative humidity, high salt content, strong solar radiation, and long sunshine. These can provide suitable conditions for mold reproduction on the surface of the wall in a building. Therefore, mildew pollution on the wall for a long time can easily damage the building’s structure. It does not only directly affect the appearance of the building, but also indirectly affects the indoor environment and human health. In this paper, dominant fungi in the residential buildings on thee Nansha Islands of China are Aspergillus, Penicillium, and Cladosporium. Critical lines of temperature and relative humidity for mould growth on the interior surfaces of island residential building envelopes have been given and discussed. The results show that the risk of mould growth on the wall with different materials, from low to high, is reinforced concrete, aerated concrete block, coral aggregate, brick, and wood. Furthermore, in order to prevent the room regulated by air conditioner from being contaminated by mould, indoor air temperature should be set variable and controlled between 26 ◦C and 28 ◦C, the relative humidity should be changed between 50% and 80%.

Keywords: island residential buildings; dominant fungi; design parameters of air conditioner; mold-prevention and antibacterial

1. Introduction Several hundred species of fungal and bacterial can usually be found in indoor environments [1,2]. Moisture accumulation can lead to mold growth on the surface of building envelopes. Mold spores are generated inside a room and on the surface of the walls of different building materials, and can be transferred by the flowing air and the activities of personnel. However, spores can germinate and produce mycelium in a dormant state, and then reproduce under appropriate conditions. On one hand, the structure of building envelopes can be damaged by mold growth, which could cause a dark color or obvious color change on the surface of the wall. However, there is no obvious pigmentation when effective mold grows and it is not easily found, even if the number of molds is very rich. On the other hand, existing studies have shown that respiratory tract infections, asthma, dermatitis and other allergies, and even infectious diseases can be caused by exposure to or the inhalation of mold and its metabolites for a long time, as confirmed by the Institute of Medicine (IOM) and the World Health Organization (WHO) [3–5]. In Northern Europe and North America, according to the estimation, 20% to 40% of buildings are contaminated by indoor mold [6], which has a significant impact socially and economically [7,8]. For example, costs related to indoor mold pollution have been estimated by the United States and Scandinavia, where the results show that annual

Int. J. Environ. Res. Public Health 2020, 17, 7316; doi:10.3390/ijerph17197316 www.mdpi.com/journal/ijerph Int. J. Environ. Res. Public Health 2020, 17, 7316 2 of 16 social and economic costs caused by high humidity and mold growth are 2.3–4.7 billion US dollars for allergic rhinitis and 1.1–2.3 billion US dollars for acute rhinitis [5]. Furthermore, the municipal annual costs for repairing public property damaged by high humidity and mold growth reached 5 billion euro, accounting for 1.9% of Finland’s GDP in 2012, and the annual cost of health problems caused by severe dampness and mold damage reached 450 million euro [9]. When mold grows on the wall, it is almost impossible to eradicate [10] as mold spores always exist in the air, whose content is directly related to the seasonal changes and specific conditions of outdoor climate [11]. The reproduction ability of mold spores is extremely strong, which can germinate and produce hyphae under a suitable condition. Therefore, the environmental parameters should be controlled before mold can germinate [12]. The affecting environmental parameters include temperature [13], relative humidity [14–16], nutrients [17], pH value [18], surface roughness, etc. [19]. Among them, temperature and relative humidity are the main factors impact on mold growth [20–22]. Therefore, indoor air temperature and relative humidity should be controlled before spores are germinated. The Nansha Islands are located in the south of China, and the geographical location is shown in Figure1. Due to the typical Tropical Ocean monsoon climate and significant meteorological characteristics of high temperature and relative humidity, mold can grow on the surface of the wall effectively. In this paper, the dominant species of indoor mold in island residential buildings was determined by literature searches. The critical temperature and humidity for mold growth on the surface were found for when different materials were utilized on the building envelopes of residential buildings on Nansha Island. Finally, the indoor air design parameters and selection criteria of air conditioner for residential buildings on the Nansha Islands, China are proposed to prevent mold and bacteria. These results can be proposed and fill in the gaps in the design code for the heating, ventilation, and air conditioning of civil buildings.

Figure 1. Countries and regions near the Nansha Islands, China.

2. Materials and Methods

2.1. Investigations and Measurements Mold growth is affected by many factors such as air temperature, relative humidity, pH value, and operation of the air conditioner. Furthermore, other important factors in indoor mold contamination include geographical location, meteorological conditions, the materials and structures of the building envelopes, the phenomenon of moisture, personnel activities on the utilization of air conditioners, etc. The above factors were included in a questionnaire (shown in AppendixA) for investigation. A total Int. J. Environ. Res. Public Health 2020, 17, 7316 3 of 16 of 224 questionnaires were effective in the Nansha Islands, China. A total of 138 out of 224 were in multi-story residential buildings and 106 out of 224 were in single family dwellings in some villages. Measurements of indoor air environment parameters included temperature, relative humidity, air velocity, and CO2 concentration. Indoor air testing parameters were monitored at the breathing zone height (1.1 m above the floor) according to the National Indoor Air Quality Standard (GB/T 18883-2002) [23]. Characteristics of the above instruments are shown in Table1. These measured data were recorded every five minutes.

Table 1. Characteristics of instruments for measuring indoor environmental parameters.

Indicator Instrument Rang Accuracy Temperature WSZY-2 Recorder 40~100 C 0.5 C − ◦ ± ◦ Relative humidity WSZY-2 Recorder 0~100% RH 3% ± Air velocity WFWZY-1 Recorder 0.05~30 m/s 0.05 m/s ± CO concentration WEZY-1S 0~5000 ppm 50 ppm 2 ±

The characteristics of the outdoor environmental parameters in the Nansha Islands of China are shown in Figure2. It can be seen that the daily average temperature exceeds 26 ◦C on 276 days, which accounts for 75.6% in a year. The lowest monthly average temperature is 22 ◦C in January, and the highest temperature is 29.6 ◦C in June. The annual temperature difference is 7.1 ◦C. The days with a temperature difference below five accounts for 90.1%.

Figure 2. Cont. Int. J. Environ. Res. Public Health 2020, 17, 7316 4 of 16

Figure 2. Climate analysis of Nansha Island. (a) Daily average temperature and relative humidity; (b) Frequency of daily average temperature; (c) Monthly average temperature and relative humidity; (d) Daily temperature variation; (e) Annual hourly wind rose; (f) Monthly solar radiation.

Monthly average relative humidity of the whole year is above 75%. The frequency of wind speed higher than 5 m/s accounts for 31%. The daily solar radiation on the horizontal plane is more than 4.5 (kw h)/m2. Above all, the characteristics of outdoor climate are high temperature, high relative · humidity, high salt content, strong solar radiation, and long sunshine time. In addition, typhoon and heavy rainfall always occur in the monsoon period.

2.2. Materials of Building Envelopes According to the results of the investigation, the materials of building envelopes were reinforced concrete, aerated concrete block, brick and concrete, and wood in the Nansha Islands residential buildings of China. The moldy phenomenon of diﬀerent types of walls is very serious. The mold growth risk on the surface of the wall from high to low was: wood wall, brick concrete, aerated concrete block, reinforced concrete, and coral aggregate wall [24–28]. According to the survey results, the structures of these ﬁve building envelopes and the layout of testing points are shown in Figure3. The physical parameters of each material layer are listed in Table2.

Figure 3. Cont. Int. J. Environ. Res. Public Health 2020, 17, 7316 5 of 16

Figure 3. Diﬀerent structures of building envelopes. (a) Reinforced concrete; (b) Aerated concrete block; (c) Brick wall; (d) Wood wall; (e) Coral aggregate wall.

Table 2. Each of the material property parameters of the above building envelopes [29].

Density Porosity Speciﬁc Heat Capacity Thermal Conductivity Material kg/m3 m3/m3 J/(kg K) W/(m K) · · Cement mortar 2000 0.28 850 0.930 XPS 40 0.95 1500 0.030 Reinforced concrete 1600 0.31 850 1.740 Aerated concrete 600 0.72 850 0.140 Brick 1890 0.28 860 0.955 Oriented strand board 600 0.60 1400 0.120 Wood wall (containing ﬁber insulation cotton) 30 0.97 800 0.047 Unidirectional moisture-proof paper 1800 0.25 1600 0.177 Anticorrosive wood hanging board 470 0.52 2000 0.150 Coral aggregate hollow block 1151 0.31 6300 0.590 Internal mixed mortar 1780 0.28 850 0.700

2.3. Use of Air Conditioner The survey results showed that the indoor air temperature of the room with the air conditioner was between 22 ◦C and 28 ◦C, mainly concentrated at 25 ◦C. The operation period of air conditioners is from April to October. During other times, the main method is natural ventilation. A total of 86.1% of users preferred to turn oﬀ their air conditioners and open windows for ventilation at night, however, most people preferred to use air conditioners during the daytime.

2.4. Dominant Fungi Among these 244 valid questionnaires, serious mold contamination accounted for 203 (83.2%), and the time of mold contamination was mainly from April to October. Asthma is one of the most common diseases, which accounts for 3.0%. In addition, respiratory diseases such as rhinitis, pharyngitis, symptoms of nasal and throat discomfort, and skin rash accounted for 52%. However, the results of other 41 questionnaires reﬂected that while there was no mold contamination in the buildings, 24 of them still reﬂected the above symptoms. These results show that there is a strong correlation between mold contamination and respiratory diseases. Dominant fungi of indoor mold (on the surface or in the air) in island residential buildings on the Nansha Islands of China were investigated and the results are listed in Table3, where the detection results of corresponding fungi are marked by “√”. Each detection rate percentage is given according to the reference [30–35]. According to these results, the dominant fungus in island residential buildings were Aspergillus and Penicillium, followed by Cladosporium. The growth trend of these fungus was isoline. Int. J. Environ. Res. Public Health 2020, 17, 7316 6 of 16

Table 3. Dominant fungi in island residential buildings near Nansha Islands [30–35].

Countries and Regions Kinds of Fungi Guangzhou in China Shenzhen in China Hongkong in China Malaysia Cambodia Singapore (Ratio %) (Ratio %) (-) (-) (Ratio %) (-) √ √ √ Asperaillus √ √ √ (30.2%) (15.58%) (76.3%) √ √ √ Penicillium √ √ √ (28.6%) (29.7%) (74.9%) √ Cladosporium - √ -- √ (26.7%) √ Rhizopus -- √ -- (5.6%) Bipolar Fungi ----- √ Fusarium --- √ - √ Zygomycetes --- √ -- Saccharomyces ----- √

2.5. Numerical Modeling

2.5.1. Heat and Moisture Transfer Model of the Wall

Model and Grid The mathematical models used for simulation were based on the energy equilibrium and moisture equilibrium. The critical curve model of mold growth is the isopleth model [36]. In this paper, the computational domain was from the outside to the inside of the wall and included the inner surface of the wall. The method used for dividing the mesh was inner node. Compared to the outer node method, the nodes at the interface between layers contain only one material, so it is easy to discretize the mesh. In addition, the mass equation and energy equation can be discretized by the control volume method. The time format is implicit. As a result, the average absolute errors of temperature and relative humidity were 0.06 ◦C and 0.11%, respectively [35,36].

Assumptions Heat transfer and moisture transfer are a coupled process in the state of gas diffusion. • Water molecules are attached on the wet side and fixed on the polymer, which is then transported • through the expansion. Liquid water is transported in the porous materials of building envelopes. • The hysteresis curve of moisture can be ignored. • Under total pressure difference, the impact of air flowing and water freezing on the transport of • enthalpy and moisture should be considered.

Boundary Boundary conditions were considered and are listed in Table4. In this study, the results of the simulation were for one year. The time step for calculation was set up one hour until the variation of temperature and relative humidity were stable.

Initial Conditions

The initial temperature on the surface of the wall was 20 ◦C, and moisture content on the surface of the wall was 80%. Annual variation of indoor air parameters are shown in Figure4. The average temperature of indoor air in one year was 27.3 ◦C. Relative humidity of one year exceeded 80%. Int. J. Environ. Res. Public Health 2020, 17, 7316 7 of 16

Table 4. Boundary conditions.

Equation Heat and Humidity Transfer Mechanism Expression of Boundary Conditions Required Data Input Data Indoor and outdoor air temperature and Vapor diffusion Vapor diffusion coefficient 1. Typical meteorological year data relative humidity (steam partial pressure) (hourly temperature, relative humidity, Rainwater flow density of horizontal solar radiation, rainfall, wind direction, plane, rainwater flow density wind speed, etc.). Rain Rainwater model and applied flux Equilibrium Equation perpendicular to the wall, outdoor wind 2. Indoor design air parameters and direction and wind speed air-conditioning use behavior. 3. Ventilation rate of air-conditioning is Water pressure, flow rate, flow Water film Surface value and applied flux 0.5 times/h temperature, outdoor air temperature 4. Initial temperature was 20 ◦C and Indoor and outdoor air temperature and relative humidity was 80%. Heat conduction Heat conductivity coefficient relative humidity The outer surface absorption rate of Direct solar radiation, scattered solar short-wave radiation was set at 0.6, Solar short-wave radiation Solar radiation model and applied flux radiation, shielding and the emissivity of long wave radiation Energy Equation was set at 0.9. Outdoor air temperature and relative Solar long wave radiation Boltzmann calculation Typical meteorological year data. humidity, cloud cover Int. J. Environ. Res. Public Health 2020, 17, 7316 8 of 16

Figure 4. Indoor air temperature and relative humidity of a room under condition of natural ventilation. (a) Temperature; (b) Relative humidity.

Simulation Conditions According to the results of the 244 questionnaire surveys, the period of air conditioner operation in one year was from April to October. Simulation conditions included: natural ventilation, air conditioner operating at night, air conditioner operating in the daytime, and air conditioner operating 24 h a day.

2.5.2. Prediction Model of Mold Growth Series of WUFI software was developed by the Fraunhofer Institute of Building Physics (IBP). WUFI-Bio, an additional software of the WUFI series software, was applied to estimate the risk of mold growth to the wall. The heat and moisture transfer process of the wall can be simulated by WUFI-Plus. Then, the calculated results by WUFI-Plus can be taken as the boundary condition and input into WUFI-Bio to simulate the mold growth process of the wall.

Calculation Process The calculation process of the WUFI-Bio software is shown in Figure5.

Figure 5. Calculation process via WUFI-Bio.

Simpliﬁed Conditions This model was used to simulate mold growth inside the wall or on the surface of the wall. The model of heat and moisture transfer can only be used to evaluate mold growth. The simpliﬁcations were as follows:

According to the literature investigation, the spatial and temporal distribution of the pH value of • the Nansha Islands’ marine climate showed that the general surface layer (0–10 m) on the building Int. J. Environ. Res. Public Health 2020, 17, 7316 9 of 16

surface was 8.2–8.5 [37]. After sedimentation, the pH value was between 6.5 and 7.2 [38], which is neutral. Therefore, it was considered that the pH range in the salt fog environment of Nansha Islands of China was from 6.5 to 8.5. As shown in Figure6, suitable pH values for mold growth are given [39–46]. It can be seen that Penicillium and Aspergillus are the most suitable for growth. Some factors should be considered such as illumination, oxygen content, and surface roughness. • Most molds grow both in anaerobic and aerobic environments. Molds cannot synthesize organic matter by itself, so the condition of light cannot significantly affect mold growth [47–49]. The influence of sediment or pollutants on the surface of building envelopes was not considered. • The diffusion resistance of mold spores cannot be measured. Actually, the balance difference of • water vapor inside the spore is very small under unsteady conditions. In addition, the value was as the same as the isoline model under steady conditions.

Figure 6. pH value for mold growth [39–46].

Assumptions Through WUFI-Bio simulation calculation, the annual growth diameter variation of bacteria was influenced by the structures and materials of different walls, and the utilization behavior of the air conditioner, and the temperatures and relative humidity of indoor air can be obtained. Surface roughness of different building materials directly affects the performance of moisture storage, then indirectly affects mold growth [47]

3. Results

3.1. Annual Growth Diameter of Bacteria

3.1.1. Natural Ventilation Under the condition of natural ventilation, the diameter variation of mold growth on each monitoring point of building envelope, constructed by reinforced concrete, is discussed. The results are shown in Figure7, where the growth diameter of each monitoring point exceeds the limit value (50 mm one year), and the result at monitoring point D exceeded 200 mm a year. Furthermore, the risk of mold contamination exists at every monitoring point, and the risk from high to low was point D, point C, point B, and point A. Int. J. Environ. Res. Public Health 2020, 17, 7316 10 of 16

Figure 7. Annual growth diameter of bacteria at each monitoring point layer under the natural ventilation condition.

3.1.2. Use of Air Conditioner in the Daytime In Figure8, Zone I refers to a thermal comfort area with the risk of mold contamination; Zone II refers to a thermal discomfort area with the risk of mold contamination; Zone III refers to a thermal comfort area without the risk of mold contamination; and Zone IV refers to a thermal discomfort area without the risk of mold contamination. The vertical dash line was 70% of the maximum relative humidity to meet the thermal comfort area, and the horizontal dash line was the critical value of 50 mm per year of growth diameter with mold contamination. Therefore, the graph was divided into four parts.

Figure 8. Annual growth diameter of bacteria at each monitoring point by using air conditioning in the daytime. (a) Point A; (b) Point B; (c) Point C; (d) Point D. Int. J. Environ. Res. Public Health 2020, 17, 7316 11 of 16

As shown in Figure8, when the air conditioner was operated in the daytime, the annual growth diameter of bacteria at each monitoring point under diﬀerent conditions of temperature and relative humidity are given. In addition, the risk of mold contamination was analyzed combined with the thermal comfort area. As the temperature variation was from 24 ◦C to 28 ◦C and the relative humidity variation was from 40% to 80%, the growth length of mycelium on each monitoring point was directly proportional to the indoor air temperature and relative humidity. Furthermore, the risk of mold contamination was always generated on monitoring point D, which was not aﬀected by any indoor environmental factors. However, under the same temperature and relative humidity, the order of mycelium growth diameter from large to small was point D, point C, point B, and point A, and the order of risk from high to low was point D, point C, point B, and point A.

3.2. Critical Line of Temperature and Relative Humidity The annual growth diameter of mold is 50 mm, and the critical lines of temperature and relative humidity of each monitoring point under different conditions are given in Figure9. Above the critical line, it illustrates that there is a risk of mold contamination in the room. In contrast, it illustrates that there is no risk of mold contamination in the room under the same indoor environment. By comparing these critical lines of five building materials, it can be seen that the indoor air temperature and relative humidity of air conditioners for preventing mold and bacteria in residential buildings on Nansha Islands can be given (Figure9). By comparing three working conditions of the air conditioner, the risk of mold contamination in the room using the air conditioner in the daytime was the highest. The order of annual bacteria growth diameter from large to small was air conditioner operated in the daytime, at night, and 24 h a day. In addition, risk of mold growth on the wall, constructed with different five materials, from low to high was reinforced concrete, aerated concrete block, coral aggregate, brick, and wood.

Figure 9. Critical lines of temperature and humidity of an air conditioner for mold prevention on the internal surface of wall. (a) Point A; (b) Point B; (c) Point C. Int. J. Environ. Res. Public Health 2020, 17, 7316 12 of 16

Therefore, our suggestions are as follows. First, materials of the residential buildings should be reinforced concrete and aerated concrete block. Second, the air conditioner should be turned on all day, especially the dehumidiﬁcation function. Third, the indoor air temperature should be kept at 26 ◦C, and the indoor air relative humidity should be maintained at 50% by the air conditioner.

4. Discussions The occurrence of asthmatic symptoms is higher in most island residential buildings. The impacts of environmental parameters including temperature, relative humidity, nutrients, pH value, surface roughness, ventilation rate, etc., on mold growth have been researched in [50–54]. Temperature and relative humidity are the most important factors in the room regulated by an air conditioner. Fungi is more suitable for growth in the range of 15~40 ◦C[55]. Some investigations have studied the impact of temperature and relative humidity on the mold growth and reproduction in the building with an air conditioning system. It was found that a higher RH level is the main factor impacting on mold growth while the indoor air temperature was between 24 ◦C and 28 ◦C by air conditioner [56]. However, a reduction could be found in bacteria viability when temperatures were above 24 ◦C[57]. According to the design code for the design of heating, ventilation and air conditioner of civil buildings (GB 50736-2016) [58], the air design temperature and relative humidity only combine with the human comfort zone. Therefore, on the particularity of island buildings, the critical indoor air design temperature and relative humidity of the air conditioner to prevent mold and bacteria should be taken into careful consideration. In addition, results in this research are similar to results in [56,57]. Indoor air design temperature should be variable, and controlled between 24 ◦C and 28 ◦C, while relative humidity is between 40% and 80%.

5. Conclusions Through literature reviews, field surveys, and numerical simulations, dominant species of mold in island residential buildings in Nansha Islands of China were obtained. The dominant species were Aspergillus, Penicillium, and Cladosporium. Mold growth risk on the wall with different materials from low to high was reinforced concrete, aerated concrete block, coral aggregate, brick, and wood. Indoor air design parameters for air conditioners for island residential buildings on the Nansha Islands of China were proposed to prevent mold and act as an antibacterial. The indoor air design temperature should be variable, and controlled between 26 ◦C and 28 ◦C, with the relative humidity between 50% and 80%. The influence of local microclimate formed by wind speed, wind direction, rainfall, and other meteorological characteristics on mold growth needs to be further studied. The development of new envelope materials could also be further researched.

Author Contributions: Methodology, X.Z. and Y.L.; Software, J.L. and B.W.; Validation, X.Z., J.L., and B.W.; Investigation, J.X., X.Z., and J.L.; Resources, X.Z., J.L., and J.X.; Data curation, X.Z. and J.L.; Writing—original draft preparation, X.Z., J.L., and B.W.; Writing—review and editing, X.Z. and J.L.; Project administration, Y.L. and X.Z. All authors have read and agreed to the published version of the manuscript. Funding: This research received no external funding. Acknowledgments: The work was supported by the National Key R&D Program (2018yfc0704055), and the NSFC Programs (No.91743102, 51308088, 52078098, 51608092, 51978118). Conﬂicts of Interest: The authors declare no conﬂict of interest.

Appendix A Questionnaire on structure, humidity, and mold of island residential buildings on the Nansha Islands of China Int.Int.Int. J. Int.J.J. Environ. Environ.Environ. J. Environ. Res. Res.Res. Res. Public PublicPublic Public Health HealthHealth Health 2020 20202020 2020,, , 17 1717,, , x x17x , x 131313 of ofof13 17 1717of 17 tototo results resultsresultsto results in inin [56,57]. [56,57].[56,57].in [56,57]. Indoor IndoorIndoor Indoor air airair designair designdesign design temperatur temperaturtemperatur temperatureee should shouldshoulde should be bebe variable, variable,bevariable, variable, and andand and controlled controlledcontrolled controlled between betweenbetween between 24 2424 °C °C24°C °C andandandand 28 2828 °C, °C,28°C, °C, while whilewhile while relative relativerelative relative humidity humidityhumidity humidity is isis between between betweenis between 40% 40%40% 40% and andand and 80%. 80%.80%. 80%.

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AuthorAuthorAuthorAuthor Contributions: Contributions:Contributions: Contributions: Methodology, Methodology,Methodology, Methodology, X.Z. X.Z.X.Z. X.Z. and andand and Y.L.; Y.L.;Y.L.; Y.L.; Software, Software,Software, Software, J.L. J.L.J.L. J.L.and andand and B.W.; B.W.;B.W.; B.W.; Validation, Validation,Validation, Validation, X.Z., X.Z.,X.Z., X.Z., J.L., J.L.,J.L., J.L., and andand and B.W.; B.W.;B.W.; B.W.; Investigation,Investigation,Investigation,Investigation, J.X., J.X.,J.X., J.X., X.Z., X.Z.,X.Z., X.Z., and andand and J.L.; J.L.;J.L.; J.L.; Resources, Resources,Resources, Resources, X.Z., X.Z.,X.Z., X.Z., J.L., J.L.,J.L., J.L., and andand and J.X.; J.X.;J.X.; J.X.; Data DataData Data curation, curation,curation, curation, X.Z. X.Z.X.Z. X.Z. and andand and J.L.; J.L.;J.L.; J.L.; Writing WritingWriting Writing———originaloriginaloriginal—original draftdraftdraftdraft preparation, preparation,preparation, preparation, X.Z., X.Z.,X.Z., X.Z., J.L., J.L.,J.L., J.L., and andand and B.W.; B.W.;B.W.; B.W.; Writing WritingWriting Writing———reviewreviewreview—review and andand and editing, editing,editing, editing, X.Z. X.Z.X.Z. X.Z. and andand and J. J.J.L.;L.;L.; J. Project ProjectL.;Project Project administration, administration,administration, administration, Y.L. Y.L.Y.L. Y.L. andandand and X.Z.. X.Z..X.Z.. X.Z.. All AllAll authorsAll authorsauthors authors have havehave have read readread read and andand and agreed agreedagreed agreed to toto the the theto publishethe publishepublishe publisheddd version versionversiond version of ofof the the theof manuscript.the manuscript.manuscript. manuscript.

Funding:Funding:Funding:Funding: This ThisThis This research researchresearch research received receivedreceived received no nono external externalnoexternal external funding. funding.funding. funding.

Acknowledgments:Acknowledgments:Acknowledgments:Acknowledgments: The TheThe The work workwork work was waswas was supported supportedsupported supported by byby the thebythe theNational NationalNational National Key KeyKey Key R&D R&DR&D R&D Program ProgramProgram Program (2018yfc0704055), (2018yfc0704055),(2018yfc0704055), (2018yfc0704055), and andand and the thethe the NSFCNSFCNSFCNSFC Programs ProgramsPrograms Programs (No.91743102, (No.91743102,(No.91743102, (No.91743102, 51308088, 51308088,51308088, 51308088, 52078098, 52078098,52078098, 52078098, 51608092, 51608092,51608092, 51608092, 51978118). 51978118).51978118). 51978118).

ConflictsConflictsConflictsConflicts of ofof Interest: Interest: Interest:of Interest: The TheThe The authors authorsauthors authors declare declaredeclare declare no nono conflicts conflictsnoconflicts conflicts of ofof interest. interest. interest.of interest.

AppendixAppendixAppendixAppendix A AA A

Int.QuestionnaireQuestionnaireQuestionnaire J. Environ.Questionnaire Res. Public on onon structure,on Healthstructure,structure, structure,2020, 17humidity, humidity,humidity,, 7316humidity, and andand and mold moldmold mold of ofof island islandofisland island residential residentialresidential residential buildings buildingsbuildings buildings on onon the onthethe the Nansha NanshaNansha Nansha 13 of 16 IslandsIslandsIslandsIslands of ofof China ChinaChinaof China I.I. PersonalPersonal informationinformation I. I.PersonalI. Personal Personal information information information Gender:Gender:Gender:Gender: Age: Age:Age: Age: Gender: Age: II.II. ResidentialResidential buildingbuilding informationinformation II.II. II.Residential Residential Residential building building building information information information 1.1.1. What WhatWhat1. What is isis the the theis the built builtbuilt built time timetime time of ofof your youryourof your building? building?building? building? 1. What is the built time of your building? □□□ Before BeforeBefore□ Before 1980 19801980 1980 □ □□ 1980~1990 1980~19901980~1990 □ 1980~1990 □ □□ 1991~2000 1991~20001991~2000 □ 1991~2000 □ □□ 2001~2010 2001~20102001~2010 □ 2001~2010 □ □□ Since SinceSince □ Since 2011 20112011 2011 Before 1980 1980~1990 1991~2000 2001~2010 Since 2011 2.2.2. What WhatWhat2. What is isis the the theis the material materialmaterial material of ofof the thetheof the building buildingbuilding building envelope? envelope?envelope? envelope? 2. What is the material of the building envelope?

Int.Int.Int. J. Int. J.J. □Environ. □ Environ.□Environ. RubbleJ. RubbleRubble □Environ. Rubble Res. Res.Res. brick brick brickRes.Public PublicPublic brick Public wall wallHealth wall HealthHealth wall Health 2020 20202020 2020, ,,17 1717□,□ ,□,,x x 17Redx Red Red □, x Red brick brickbrick brick wall wallwall wall □□□ Dust DustDust□ Dust brick brickbrick brick wall wallwall wall □ □□ Hollow HollowHollow□ Hollow brick brickbrick brick wall wallwall141414 wallof of 14of 17 1717of 17 Rubble brick wall Red brick wall Dust brick wall Hollow brick wall

□□□ Reinforced ReinforcedReinforced□ Reinforced concrete concreteconcrete concrete □□□ Aerated AeratedAerated□ Aerated concrete concreteconcrete concrete block blockblock block □□□ Wood WoodWood□ Wood □□□ Coral CoralCoral□ Coral Aggregate AggregateAggregate Aggregate Reinforced concrete Aerated concrete block Wood Coral Aggregate 3.3.3. What WhatWhat3. What is isis the the theis the material materialmaterial material on onon theon thethe the inner innerinner inner surface surfacesurface surface of ofof the theofthe the wall? wall?wall? wall? □□□ Wooden Wooden3.Wooden□ WhatWooden isboard boardboard the board material □ □□ Lime LimeLime □ Lime mortar mortar onmortar mortar the inner□ □□ Latex LatexLatex □ Latex surface paint paintpaint paint of □ □□ Cement theCementCement □ Cement wall? □ □□ Wall WallWall □ Wall paper paperpaper paper □ □□ Ceramic CeramicCeramic □ Ceramic tile tiletile tile □ □□ Other OtherOther □ Other 4.4.4. How HowHow4.Wooden How about aboutabout about board the thethe the natural naturalnatural naturalLime ventilation ventilationventilation mortar ventilation inLatex inin your youryourin your paint building? building?building? building? Cement □ □□ Best BestBest □ Best Wall □ □□ Better BetterBetter □ paperBetter □ □□ General GeneralGeneral □Ceramic General □ □□ Bad BadBad tile□ Bad □ □□ Worse WorseOtherWorse □ Worse 5.5.5. How4. HowHow5. HowHow is isis your your aboutyouris your building buildingbuilding the building natural after afterafter after ventilation ventilation? ventilation?ventilation? ventilation? in □ □your□ No NoNo □ No obvious building?obviousobvious obvious smell smellsmell smellBest at atat all, all, all,atBetter all, fresh freshfresh fresh air airairGeneral □ air □□ No NoNo □ No obvious obviousobvious obviousBad smell, smell,smell,Worse smell, goodgoodgood5.good Howair airair □air □□ Peculiar isPeculiarPeculiar □your Peculiar building smell, smell,smell, smell, common commoncommon after common ventilation? air airair qualityair qualityquality quality □ □□ Obvious ObviousObvious No□ Obvious obvious smell, smell,smell, smell, smell need needneed need at ventilation ventilationventilation all, ventilation fresh air for forfor fora aa Nolong longlong a long obvious time timetime time smell,□□□ Other OtherOther□ good Other air Peculiar smell, common air quality Obvious smell, need ventilation for a long time III.III.III. III. Moisture MoistureOtherMoisture Moisture feeling feelingfeeling feeling and andand and physical physicalphysical physical condition conditioncondition condition III.1.1.1. Moisture How HowHow1. How do dodo youdo feelingyouyou you feel feelfeel feel and during duringduring during physical the thethe the day dayday condition day time? time?time? time? □ □□ Very VeryVery □ Very dry drydry dry □ □□ Dry DryDry □ Dry □ □□ Moderate ModerateModerate □ Moderate □ □□ Wet WetWet □ Wet □ □□ More MoreMore □ More wet wetwet wet 2.2.2. How1. HowHow2. HowHow do dodo do youdo youyou youyou feel feelfeel feelfeel at atat night? duringnight?night?at night? □ □ the□ Very VeryVery □ day Very dry drydry time? dry □ □□ Dry DryDry □ DryVery □ □□ Moderate ModerateModerate □ dry Moderate Dry □ □□ Wet WetWet □ ModerateWet □ □□ More MoreMore □ More wet wetwetWet wet More wet 3.3.3. Have2. HaveHave3. HowHave you youyou do you ever everever you ever suffered suffered feelsuffered suffered at night? from fromfrom from asthma asthmaasthmaVery asthma dry during duringduring duringDry your youryour yourModerate stay? stay?stay? stay? □ □□ Yes YesYes □ Yes Wet □ □□ No NoNo □ No More wet IV.IV.IV. IV. Moisture MoistureMoisture Moisture3. Have and andand you and mold moldmold ever mold conditions conditions suconditions ﬀconditionsered from asthma during your stay? Yes No IV.1.1.1. Moisture How HowHow1. How about aboutabout andabout water waterwater mold water leakage leakageleakage conditions leakage or oror water waterorwater water seepage seepageseepage seepage in inin your yourinyour your building? building?building? building? (Single (Single(Single (Single or oror multiple multipleormultiple multiple choice) choice)choice) choice) □□□ Water Water1.Water□ HowWater seepage seepageseepage about seepage water on onon theon thethe leakage the roof roofroof roof □ □□ Water Water orWater □ waterWater seepage seepageseepage seepageseepage on onon in theon thethe your the wall wallwall wall building? (Single or multiple choice) □□□ Water WaterWater□Water Water seepage seepageseepage seepage seepage through throughthrough on through the doors roofdoorsdoors doors and andandWater and windows windowswindows seepagewindows □ □□ on No NoNo □the No water waterwaterwall water seepage seepageseepage seepage or oror leakage leakageorleakage leakage 2.2.2. Where WhereWhere2.Water Where is isis seepage the the theis the water waterwater water through leakage leakageleakage leakage doors or oror water waterorwater and water windowsseepage seepageseepage seepage in inin your yourNoinyour your water building? building?building? building? seepage (Single (Single(Single (Single or leakage or oror multiple multipleormultiple multiple choice) choice)choice) choice) □□□ Floor Floor2.Floor□ WhereFloor □ □□ Floor FloorFloor □ is Floor the corner cornercorner water corner □ □□ leakage Ceiling CeilingCeiling □ Ceiling □or □□ Ceiling Ceiling waterCeiling□ Ceilingseepage corner cornercorner corner □ □ in□ Wall WallWall your□ Wall □ □□ building? Other OtherOther □ Other □ □□ No NoNo □ (Single No moisture moisturemoisture moisture or multiple choice) 3.3.3. When WhenWhen3.Floor When does doesdoes Floordoes moisture moisturemoisture moisture corner regain regainregain Ceilingregain or oror water waterorwater Ceilingwater droplets dropletsdroplets droplets corner appear appearappear appearWall during duringduring Otherduring one oneone one No year? year?year? moistureyear? (Single (Single(Single (Single or oror multiple multipleormultiple multiple choice)choice)choice)choice) 3. When does moisture regain or water droplets appear during one year? (Single or multiple choice) □□□ January JanuaryJanuary□January January □ □□ February FebruaryFebruary □February February □ □□ March MarchMarch □March March □ □□ April AprilApril □ AprilApril □ □□ May MayMay □ MayMay □ □□ June JuneJune □ JuneJune □ □□ July JulyJuly □ JulyJuly □ □□ August AugustAugust □ August □□□ September SeptemberSeptember□September September □ □□ October OctoberOctober □October October □ □□ November NovemberNovember □November November □ □□ December DecemberDecember □ DecemberDecember □ □□ No NoNo □ No No resurgence resurgenceresurgence resurgenceresurgence V.V.V. V. Use UseV.Use Use Use of ofof of air airofair air conditionerair conditionerconditioner conditioner conditioner 1.1.1. What WhatWhat1. What is isis the the theis the set setset temperatureset temperaturetemperature temperature of ofof air airofair conditionerair conditionerconditioner conditioner in inin your yourinyour your home? home?home? home? □□□ ≤ ≤≤18□1818 ≤ °C °C18°C □ °C□□ 19 1919 □ °C °C19°C □ °C□□ 20 2020 □ °C °C20°C □ °C□□ 21 2121 □ °C °C21°C □ °C□□ 22 2222 □ °C °C22°C □ °C□□ 23 2323 □ °C °C23°C □ °C□□ 24 2424 □ °C °C24°C □ °C□□ 25 2525 □ °C °C25°C □ °C□□ 26 2626 □ °C °C26°C □ °C□□ 27 2727 □ °C °C27°C □ °C□□ ≥ ≥≥ 28□2828 ≥ °C °C28°C °C 2.2.2. When WhenWhen2. When do dodo youdo youyou you use useuse use air airair conditionerair conditionerconditioner conditioner during duringduring during a aa year? year?year? a year? (Single (Single(Single (Single or oror multiple multipleormultiple multiple choice) choice)choice) choice) □□□ January JanuaryJanuary□ January □ □□ February FebruaryFebruary □ February □ □□ March MarchMarch □ March □ □□ April AprilApril □ April □ □□ May MayMay □ May □ □□ June JuneJune □ June □ □□ July JulyJuly □ July □ □□ August AugustAugust □ August □□□ September SeptemberSeptember□ September □ □□ October OctoberOctober □ October □ □□ November NovemberNovember □ November □ □□ December DecemberDecember □ December 3.3.3. When WhenWhen3. When do dodo youdo youyou you use useuse use air airair conditionerair conditionerconditioner conditioner in inin a aina day? day?day? a day? (Single (Single(Single (Single or oror multiple multipleormultiple multiple choice) choice)choice) choice) □□□ 7 77 □ a.m.~9 a.m.~9a.m.~9 7 a.m.~9 a.m. a.m.a.m. a.m. □ □□ 9 99 □ a.m.~11 a.m.~11a.m.~11 9 a.m.~11 a.m. a.m.a.m. a.m. □ □□ 11 1111 □ a.m.~1 a.m.~111a.m.~1 a.m.~1 p.m. p.m.p.m. p.m. □ □□ 1 11 □ p.m.~3 p.m.~3p.m.~3 1 p.m.~3 p.m. p.m.p.m. p.m. □ □□ 3 33 □ p.m.~5 p.m.~5p.m.~5 3 p.m.~5 p.m. p.m.p.m. p.m. □ □□ 5 55 □ p.m.~7 p.m.~7p.m.~7 5 p.m.~7 p.m. p.m.p.m. p.m. □□□ 7 77 □ p.m.~9 p.m.~9p.m.~9 7 p.m.~9 p.m. p.m.p.m. p.m. □ □□ 9 99 □ p.m.~11 p.m.~11p.m.~11 9 p.m.~11 p.m. p.m.p.m. p.m. □ □□ 11 1111 □ p.m.~7 p.m.~711p.m.~7 p.m.~7 a.m. a.m.a.m. a.m. in inin the theinthe the next nextnext next day dayday day 4.4.4. When WhenWhen4. When do dodo youdo youyou you turn turnturn turn off offoff offthe thethe the air airair airconditioner conditionerconditioner conditioner an anand ddan open openopend open the thethe the windows windowswindows windows for forfor forventilation ventilationventilation ventilation during duringduring during the thethe the year?year?year?year? (Single (Single(Single (Single or oror multiple multipleormultiple multiple choice) choice)choice) choice) □□□ January JanuaryJanuary□ January □ □□ February FebruaryFebruary □ February □ □□ March MarchMarch □ March □ □□ April AprilApril □ April □ □□ May MayMay □ May □ □□ June JuneJune □ June □ □□ July JulyJuly □ July □ □□ August AugustAugust □ August □□□ September SeptemberSeptember□ September □ □□ October OctoberOctober □ October □ □□ November NovemberNovember □ November □ □□ December DecemberDecember □ December 5.5.5. When WhenWhen5. When do dodo doyou youyou you turn turnturn turn off offoff offthe thethe the air airair airconditioner conditionerconditioner conditioner an anand ddan open openopend open the thethe the windows windowswindows windows for forfor forventilation ventilationventilation ventilation in inin a aina day? day? day?a day? (Single(Single(Single(Single or oror multiple multipleormultiple multiple choice) choice)choice) choice) □□□ 7 77 □ a.m.~9 a.m.~9a.m.~9 7 a.m.~9 a.m. a.m.a.m. a.m. □ □□ 9 99 □ a.m.~11 a.m.~11a.m.~11 9 a.m.~11 a.m. a.m.a.m. a.m. □ □□ 11 1111 □ a.m.~1 a.m.~111a.m.~1 a.m.~1 p.m. p.m.p.m. p.m. □ □□ 1 11 □ p.m.~3 p.m.~3p.m.~3 1 p.m.~3 p.m. p.m.p.m. p.m. □ □□ 3 33 □ p.m.~5 p.m.~5p.m.~5 3 p.m.~5 p.m. p.m.p.m. p.m. □ □□ 5 55 □ p.m.~7 p.m.~7p.m.~7 5 p.m.~7 p.m. p.m.p.m. p.m. □□□ 7 77 □ p.m.~9 p.m.~9p.m.~9 7 p.m.~9 p.m. p.m.p.m. p.m. □ □□ 9 99 □ p.m.~11 p.m.~11p.m.~11 9 p.m.~11 p.m. p.m.p.m. p.m. □ □□ 11 1111 □ p.m.~7 p.m.~711p.m.~7 p.m.~7 a.m. a.m.a.m. a.m. in inin the theinthe the next nextnext next day dayday day

Int. J. Environ. Res. Public Health 2020, 17, 7316 14 of 16

1. What is the set temperature of air conditioner in your home? 18 C 19 C 20 C 21 C 22 C 23 C 24 C 25 C 26 C 27 C 28 C ≤ ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ ◦ ≥ ◦ 2. When do you use air conditioner during a year? (Single or multiple choice) January February March April May June July August September October November December 3. When do you use air conditioner in a day? (Single or multiple choice) 7 a.m.~9 a.m. 9 a.m.~11 a.m. 11 a.m.~1 p.m. 1 p.m.~3 p.m. 3 p.m.~5 p.m. 5 p.m.~7 p.m. 7 p.m.~9 p.m. 9 p.m.~11 p.m. 11 p.m.~7 a.m. in the next day 4. When do you turn oﬀ the air conditioner and open the windows for ventilation during the year? (Single or multiple choice) January February March April May June July August September October November December 5. When do you turn oﬀ the air conditioner and open the windows for ventilation in a day? (Single or multiple choice) 7 a.m.~9 a.m. 9 a.m.~11 a.m. 11 a.m.~1 p.m. 1 p.m.~3 p.m. 3 p.m.~5 p.m. 5 p.m.~7 p.m. 7 p.m.~9 p.m. 9 p.m.~11 p.m. 11 p.m.~7 a.m. in the next day

References

1. Arif, M.; Katafygiotou, M.; Mazroei, A.; Kaushik, A.; Elsarrag, E. Impact of indoor environmental quality on occupant well-being and comfort: A review of the literature. Int. J. Sustain. Built Environ. 2016, 5, 1–11. [CrossRef] 2. Gutarowska, B.; Akowska, Z. Elaboration and application of mathematical model for estimation of mold contamination of some building materials based on ergosterol content determination. Int. Biodeterior. Biodegr. 2002, 49, 299–305. [CrossRef] 3. Dillon, H.K.; Heinsohn, P.A.; Miller, J.D. Field Guide for the Determination of Biological Contaminants in Environmental Samples, 2nd ed.; A Publication of the American Industrial Hygiene Association: Detroit, MN, USA, 2005; pp. 4–17. Available online: https://www.researchgate.net/publication/246181889 (accessed on 18 September 2020). 4. Chameera, U.; Himahansi, G.; Ariyarathne, I.S. Mold growth and moss growth on tropical walls. Build. Environ. 2018, 137, 268–279. 5. Mudarri, D.H. Valuing the economic costs of allergic rhinitis, acute bronchitis, and asthma from exposure to indoor dampness and mold in the US. J. Environ. Public Health 2016, 2016, 2386596. [CrossRef] 6. Srikanth, P.; Sudharsanam, S.; Steinberg, R. Bio-aerosols in indoor environment: Composition, health effects and analysis. Indian J. Med. Microbiol. 2008, 26, 302–312. [CrossRef] 7. Gutarowska, B.; Piotrowska, M. Methods of mycological analysis in buildings. Build. Environ. 2007, 42, 1843–1850. [CrossRef] 8. Mudarri, D.; Fisk, W.J. Public health and economic impact of dampness and mold. Indoor Air 2007, 17, 226–235. [CrossRef] 9. Department for Communities and Local Government. Housing Health and Safety Rating System Guidance for Landlords and Property Related Professionals, 1st ed.; Department for Communities and Local Government: London, UK, 2006. 10. Gottfried, D.A.; Schoichet, E.A.; Hart, M. Green building environmental control: A case study. Heat. Pip. Air Cond. 1997, 69, 71–78. 11. Adan, O.C.G. On the Fungal Defacement of Interior Finishes; Doctor-Eindhoven University of Technology: Eindhoven, the Netherlands, 1994. 12. Molhave, L. Volatile organic compounds, indoor air quality, and health. Indoor Air 1991, 1, 357–376. [CrossRef] 13. Baughman, A.V.; Arens, E.A. Indoor humidity and human health-part I: Literature review of health effects of humidity-influences indoor pollutants. Ashrae Trans. 1996, 102, 193–211. 14. Griffin, D.H. Fungal Physiology, 2nd ed.; John Wiley and Sons: New York, NY, USA, 1981; p. 25. 15. Burch, D.M. An analysis of moisture accumulation in walls exposed to hot and humid climates. Ashare Trans. 1993, 99, 1013–1022. Int. J. Environ. Res. Public Health 2020, 17, 7316 15 of 16

16. Tenwolde, A. Steady-state one-dimensional water vapor movement by diffusion and convection in a multilayer wall. Ashare Trans. 1985, 91, 322–342. 17. Cunningham, M.J. The moisture performance of framed structures-a mathematical model. Build. Environ. 1988, 23, 123–135. [CrossRef] 18. Klaus, S. Prediction of Mold Fungus Formation on the Surface of and Inside Building Components; Doctor-Fraunhofer Institute for Building Physics: Holzkirchen, Germany, 2001. 19. Moon, H.J. Assessing Mold Risks in Buildings Under Uncertainty; Doctor-Georgia Institute of Technology: Atlanta, GA, USA, 2005. 20. Coppock, J.B.M.; Cookson, E.D. The effect of humidity on mold growth on construction materials. J. Sci. Food Agric. 1951, 2, 534–537. [CrossRef] 21. Grant, C.; Hunter, C.A.; Flannigan, B.; Bravery, A.F. The moisture requirements of molds isolated from domestic dwelling. International Biodeterioration. 1989, 25, 259–284. [CrossRef] 22. Nielsen, K.F.; Holm, G.; Uttrup, L.P.; Nielsen, P.A. Mold growth on building materials under low water activities. Influence of humidity and temperature on fungal growth and secondary metabolism. International Biodeterioration. 2004, 54, 325–336. [CrossRef] 23. Inspection and Quarantine of the People’s Republic of China; National health commission of the People’s Republic of China. Indoor Air Quality Standard (GB/T 18883-2002); China Architecture & Building Press: Beijing, China, 2002; pp. 1–12. 24. Zhao, X.D.; Xie, J.C.; Wang, J.P.; Zhi, X.; Wang, H.Y.; Zhang, X.J.; Liu, J.P. Thermal performance analysis of coral aggregate blocks suitable for island areas. New Build. Mater. 2020, 47, 62–66. 25. Wang, Y.G. Feasibility of coral concrete in Harbor Engineering. Water Transp. Eng. 1988, 12, 46–48. 26. Yu, Q.; Jiang, Z.C. Analysis on the durability of sea water coral reef sand concrete in Xisha Island. Constr. Technol. 2013, 56, 258–260. 27. Chai, T.; Draxler, R.R. Root mean square error (RMSE) or mean absolute error (MAE)?—Arguments against avoiding RMSE in the literature. Geosci. Model Dev. 2014, 7, 1247–1250. [CrossRef] 28. Viitanen, H.; Ritschkoff, A.C. Mold growth in pine and spruce sapwood in relation to air humidity and temperature. Doctor-Swedish University of Agricultural Sciences: Uppsala, Sweden, 1991. 29. Yang, S.M.; Tao, W.Q. Heat Transfer, 4th ed.; High Education Process: Beijing, China, 2006; pp. 155–180. 30. Fang, Z.G.; Ouyang, Z.Y.; Hu, L.F.; Wang, X.K.; Miao, H. Progresses of airborne microbial communities in urban ecosystem. Acta Ecol. Sin. 2004, 24, 315–322. 31. Hui, K.W.; Wong, L.T.; Hui, P.S. Risks of unsatisfactory airborne bacteria level in air-conditioned offices of subtropical climates. Build. Environ. 2008, 43, 475–479. 32. Norbck, D.; Cai, G. Fungal DNA in hotel rooms in Europe and Asia associations with latitude, precipitation, building data, room characteristics and hotel ranking. J. Environ. Monit. 2011, 13, 2895–2903. [CrossRef] [PubMed] 33. Wang, X.Y.; Liu, W.; Huang, C.; Cai, J.; Shen, L.; Zou, Z.J.; Lu, R.C.; Chang, J. Associations of dwelling characteristics, home dampness, and lifestyle behaviors with indoor airborne culturable fungi: On-site inspection in 454 Shanghai residences. Build. Environ. 2016, 102, 159–166. [CrossRef] 34. Hussin, N.H.M.; Sann, L.M.; Shamsudin, M.N.; Hashim, Z. Characterization of Bacteria and Fungi Bioaerosol in the Indoor Air of selected Primary Schools in Malaysia. Indoor Built Environ. 2011, 20, 607–617. [CrossRef] 35. Balasubramanian, R.; Nainar, P.; Rajasekar, A. Airborne bacteria, fungi, and endotoxin levels in residential microenvironments: A case study. Aerobiologia 2012, 28, 375–390. [CrossRef] 36. Lv, Y.; Liang, J.Y.; Wang, B.B.; Zhang, X.Y.; Xie, J.C. Effect of Heat and Moisture Transfer on the Growth of Mould on the Inner Surface of Walls: A Case Study in Dalian of China, Building Simulation. 2020, 13, 1269–1279. 37. Ke, D.S. Annual variation of PH in relation with temperature and sanility in south China sea. Mar. Sci. Bull. 1990, 19, 23–37. Available online: http://en.cnki.com.cn/Article_en/CJFDTotal-HUTB199003004.htm (accessed on 18 September 2020). 38. Wu, M.L.; Yao, Q.H. About change and control of Slat Liquid PH in salt mist test. Environ. Technol. 1998, 41, 2–5. 39. Long, Q.Z.; Xiong, Y.; Liu, X.; He, Q.Q. Effects of environmental factors on growth characteristics of amorp hotheca resinae. J. Logist. Eng. Univ. 2015, 31, 73–76. Available online: http://en.cnki.com.cn%20/Article_en/ CJFDTOTAL-HQGC%20201501014.htm (accessed on 15 January 2020). Int. J. Environ. Res. Public Health 2020, 17, 7316 16 of 16

40. Jiang, H.F. Effects of culture media pH on the happening of trichoderma. Edible Fungi 1997, 19, 36–76. 41. Xiao, C.L. Effects of culture media pH on the happening of penicillium. J. Jinggangshan Norm. Coll. 2001, 22, 32–33. 42. Chen, S.H. Molecular identification of seven Trichoderma strains and detection of their temperature adaptability and growth pH conditions. In Proceedings of the 2008 Annual Meeting of Chinese Society of Plant Pathology, Beijing, China, 21–25 July 2008; p. 623. 43. Luo, X.M. Effects of growth conditions on the growth state of Rhizopus. Acad. Period. Farm. Prod. Process. 2014, 13, 19–22. 44. Hou, H.F.; Qi, Y.X.; Li, Q.W. Interaction of temperature and pH on toxin production of penicillium citreoviridin. Chin. J. Public Health 2007, 26, 52–53. 45. Deacon, J.W. Modern Mycology, 3rd ed.; Publisher Blackwell Science, Verlag: Berlin, Germany, 1997; p. 10. Available online: https://www.nature.com/articles/048224a0 (accessed on 18 September 2020). 46. Fries, N. Effects of volatile organic compounds on the growth and development of fungi. Trans. Br. Mycol. Soc. 1973, 60, 1–2. [CrossRef] 47. Sedlbauer, K. Prediction of mould growth by hygrothermal calculation. J. Therm. Envelope Build. 2002, 25, 321–336. [CrossRef] 48. Vereecken, E.; Roels, S. Review of mould prediction models and their influence on mould risk evaluation. Build. Environ. 2012, 51, 296–310. [CrossRef] 49. Gradeci, K.; Labonnote, N.; Time, B.; K€ohler, J. Mould growth criteria and design avoidance approaches in wood-based materials—A systematic review. Construct. Build. Mater. 2017, 150, 77–88. [CrossRef] 50. Paula, L.A.; Hecto, A.M.; James, B. Building moisture diagnosis: Processing, assessing and representation of environmental data for root cause analysis of mould growth. Build. Simul. 2020, 13, 999–1008. 51. Asimina, S.; Pyrri, I.; Asimakopoulos, D.N. Indoor air quality and dustborne biocontaminants in bedrooms of toddlers in Athens, Greece. Build. Environ. 2020, 173, 1067556. 52. Liu, Z.J.; Ma, S.Y.; Cao, G.Q.; Meng, C.; He, B.J. Distribution characteristics, growth, reproduction and transmission modes and control strategies for microbial contamination in HVAC systems: A literature review. Energy Build. 2018, 177, 77–95. [CrossRef] 53. Brambilla, A.; Sangiorgio, A. Mould growth in energy efficient buildings: Causes, health implications and strategies to mitigate the risk. Renew. Sustain. Energy Rev. 2020, 132, 110093. [CrossRef] 54. Brambilla, A.; Gasparri, E.; Aitchison, M. Building with Timber across Australian Climatic Contexts: An Hygrothermal Analysis; International Conference of the Architectural Science Association: Australia, RMIT University, Melbourne, 2018; pp. 11–18. Available online: https://www.researchgate.net/publication/ 329519935 (accessed on 7 October 2020). 55. Cooke, R.C.; Whipps, J.M. Ecophysiology of Fungi, Blackwell Scientific Publica-Tions. University of Chicago Press: Chicago NJ, USA, 1993. 56. Foarde, K.; VanOsdell, D.; Chang, J. Evaluation of fungal growth on fiberglass duct materials for various moisture, soil, use, and temperature conditions. In-Door Air 1996, 6, 83–92. [CrossRef] 57. Tang, J.W. The effect of environmental parameters on the survival of airborne infectious agents. J. R. Soc. Interface 2009.[CrossRef][PubMed] 58. Inspection and Quarantine of the People’s Republic of China; National health commission of the People’s Republic of China. Design Code for Design of Heating, Ventilation and Air Conditioner of Civil Buildings (GB 50736-2016); China Architecture & Building Press: Beijing, China, 2002; pp. 1–12.

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