buildings

Article Influence of on the Thermal Comfort of Rooms in the Traditional Houses: A Study in ,

Jalil Shaeri 1,*, Mahmood Yaghoubi 2 ID and Amin Habibi 1

1 Faculty of Arts and Architecture, Shiraz University, Shiraz 7188637911, Iran; [email protected] 2 School of Mechanical Engineering, Shiraz University, Shiraz 7193616548, Iran; [email protected] * Correspondence: [email protected] or [email protected]; Tel.: +98-937-305-6253

 Received: 11 May 2018; Accepted: 12 June 2018; Published: 13 June 2018 

Abstract: In traditional buildings many climatic strategies have been used to provide indoor thermal comfort in south and central parts of Iran. A common element is called an . This study investigates the indoor thermal comfort of a room adjoined to a talar in a traditional house which has an iwan, in Shiraz, Iran. The data related to the temperature and relative humidity of the room are used to calculate the thermal comfort index of PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) by considering the following two cases: a talar room with an iwan and one without an iwan, by means of DesignBuilder software. For the purpose of validation, the air temperature and relative humidity of the talar room with an iwan were measured over 10 days and compared to the results of the simulation. Having a valid simulation, computation was conducted for the selected house in various cases for an annual passive operation of calculating PMV and PPD. The numerical results revealed that the talar room adjoined to an iwan located in the south front of the courtyard had relatively good conditions during the hot months, including June and July. In addition, it could provide fully satisfactory comfort conditions during August and September. According to the results, it is found that the iwan makes a talar room 62% more desirable for the hot months in comparison with a talar room without an iwan.

Keywords: iwan; thermal comfort; talar; traditional houses; PMV; PPD; indoor quality environment (IQE)

1. Introduction Today, a considerable amount of energy is spent on heating and cooling indoor environments to provide thermal comfort for the building’s residents. The availability of modern heating and cooling systems has led to little attention being paid to passive systems in modern architecture [1,2]. Greenhouse gas emissions and global warming in recent years, in addition to high energy consumption in residential sectors, have caused the emergence of a greater interest in climatic strategies. Meanwhile, more effort is devoted to using such strategies in local and traditional architecture in modern buildings [3–5]. For a long period of time, buildings and climatic strategies have been constructed based on trial and error for local and traditional buildings; however, these experiences are going to be forgotten [6,7]. Most traditional buildings in hot and dry climates have been comfortable for residences thanks to their passive temperature control systems. Also, in comparison to modern buildings, they consume less energy for air conditioning [8]. Comparisons between traditional and contemporary houses have indicated that traditional houses, which employ building design strategies, are more compatible with the environment, resulting in better thermal comfort in indoor spaces. Although in contemporary houses many technologies are used to achieve indoor thermal comfort [9–11], several studies have

Buildings 2018, 8, 81; doi:10.3390/buildings8060081 www.mdpi.com/journal/buildings Buildings 2018, 8, 81 2 of 23 indicated that passive and climatic strategies used in traditional buildings can be implemented in modern buildings [12]. Regarding traditional materials, the study of Ashrae revealed that using brick and rubble and muddy blocks in traditional houses, in comparison to the stones used in these houses, influences energy consumption in a way that leads to lower energy consumption in indoor spaces [13]. In addition, in some traditional buildings, underground space was used to take advantage of the cooling capacity of the soil, in order to cool the space and ground floor [14]. Meanwhile, materials with high thermal capacity were used to control the temperature fluctuations; interior and exterior walls were very thick and ceilings were insulated [15]. Other climatic strategies to cool indoor spaces in traditional buildings included using the forms of central courtyards, creating a semi-open spaces, and employing porches and balconies [16,17]. Bright colors are used in these buildings, as well as double and several skin ceilings and domes [18,19]. Entrance filters and intermediate spaces are applied to preserve the heat or coolness of the indoor space [20]. In order to increase humidity, ponds and trees were used in hot and dry climate, and wind catchers in several forms were applied to take advantage of wind flow. Also, windows were considered to direct the air from the central courtyard to the upper rooms [9,15,21]. In some buildings, houses have two parts, one for summer settlement and another for winter occupation [22], and for each side of the house the central courtyard is devoted to one season [7]. Orientations of these buildings were usually toward the southeast and a dense pattern of urbanization was commonly used in organizing such buildings [9]. The most important climatic characteristic in most traditional houses of Iran in the warm and dry climate is the iwan with a high vault, which is considered useful for all activities of life. One of its sides is open, overlooking the yard, and the other two sides are half closed. The fourth side is closed, which may take one of several forms and has been made with various materials and sizes in different areas and cities, as shown in Figure1. The closet space is called the talar. The talar room often has a sash and grille made of wood and glass. Foruzanmehr [21] studied iwans and of traditional houses in , Iran, in a qualitative way and indicated that residents were satisfied with the space of the iwan and talar as it enabled communication with outdoor space in addition to providing privacy and thermal comfort. Atrvash and Fayaz [23] studied the effect of sash windows in three positions of open, semi-closed, and closed on the flow indoor, which were simulated by COMSOL software (version 3.3a, Comsol Multiphysics, Stockholm, Sweden). Their studies showed that sashes in the open position conducted flow directly from the courtyard toward the top of the room, which resulted in the movement and rotation of air in a considerable volume of the room. For semi-closed sashes, limited flow in the bottom of the room with a lower volume of movement took place. As an effective strategy, courtyards were also used in the vernacular architecture to bring suitable thermal conditions to the residential buildings. A study by Ryu et al. [24] indicated that due to cold weather between the yard and the backyard of traditional houses, the temperature difference could provide a comfortable situation for the indoor environment. The differences between the temperatures in the designed courtyards created mild air velocity in the adjacent rooms. In a study of a vernacular house in Oman, the sea breeze was used to moderate the high relative humidity inside the house by means of natural ventilation [25]. In general, vernacular houses near coastal areas have been designed sophisticatedly to lead wind directly and indirectly to buildings [26]. In order to apply wind sufficiently in these buildings and use maximum sunlight in the cold seasons, buildings have been orientated in the east-west direction [4]. Shading devices have been installed horizontally and vertically on top of windows and apertures have been employed, especially in the south direction, to sufficiently fulfill heat avoidance techniques. By controlling intensive solar radiation through the application of shadings in balconies as well as the increase of cross-ventilation through the shaded windows, acceptable indoor thermal conditions have been supplied in vernacular houses [4,5,27]. Buildings 2018,, 8,, 81x FOR PEER REVIEW 3 of 23

Lighter colors on the outer surfaces and local materials with low thermal conductivity such as Lighter colors on the outer surfaces and local materials with low thermal conductivity such wood, bamboo or palm tree trunks, stone, mud, and lime are used in buildings to reduce the as wood, bamboo or palm tree trunks, stone, mud, and lime are used in buildings to reduce the transformation of heat from outside to the inside [28]. The central courtyard in this region is small so astransformation to receive less of heat sunlight from outsideduring to the the day. inside The [28 ]. heat The iscentral easily courtyard transferred in this to region the surrounded is small so environmentas to receive less during sunlight the nighttime during the through day. The the heat external is easily surfaces transferred of the to thecourtyard surrounded and environmentroof. This in turnduring helps the the nighttime building through to act as the a heat external sink surfacesand remove of the the courtyard heat quickly and [27] roof.. This in turn helps the building to act as a heat sink and remove the heat quickly [27].

(a) (b)

(c) (d)

(e) (f)

Figure 1. 1. IwansIwans of of Iran’s Iran’s traditional traditional buildings buildings in different in different climates: climates: (a) iwan (a) i ofwan Behnam of Behnam house house in in (coldTabriz climate); (cold climate) (b) iwan; ( ofb) Boroujerdi iwan of Boroujerdi house in house (hot in Kashan and dry ( climate);hot and ( dryc) iwan climate) of Bekhradi; (c) iwan house of Bekhradiin Esfehan house (hot and in Esfehan dry climate); (hot and (d) iwan dry climate); of Lariha ( housed) iwan in ofYazd Lariha (hot house and dry in climate); Yazd (hot (e ) and iwan dry of Amiriehclimate); house(e) iwan in Bushehrof Amirieh (hot house and humidin Bushehr climate); (hot (andf) iwan humid of Rahimi climate) house; (f) iwan in Bitam of Rahimi village, house Anzali in (mildBitam andvillage, humid Anzali climate). (mild and humid climate).

Fernandes et al. [29] studied the climate strategies in vernacular architecture from the northern and southern parts of Portugal, specifically in the Beira Alta and Alentejo areas, respectively. They selected a case study and used experimental tests to obtain measurements of hygrothermal and surveyed thermal sensations on occupants. Their results indicated that the vernacular houses Buildings 2018, 8, 81 4 of 23

Fernandes et al. [29] studied the climate strategies in vernacular architecture from the northern and southern parts of Portugal, specifically in the Beira Alta and Alentejo areas, respectively. They selected a case study and used experimental tests to obtain measurements of hygrothermal and surveyed thermal sensations on occupants. Their results indicated that the vernacular houses showed good thermal performance by passive strategies and the occupants felt thermal comfort. However, the occupants needed to use simple heating systems during the winter. Glazed balconies which were used in Beira Alta played a good strategy role receiving solar gains; in Alentejo, the focus was on passive cooling strategies and courtyards represented a good strategy for shading to reduce temperature. Another study investigated the thermal conditions of a vernacular building in Evora, Portugal. The results revealed that the passive cooling techniques used in vernacular buildings can improve indoor thermal comfort during the summer season. The difference between the indoor temperature and the maximum outdoor temperature in the courtyard and in the city center was respectively 7 ◦C and 16 ◦C. Several passive strategies used in vernacular houses can be mentioned as follows: small exterior doors and windows, high thermal inertia walls, white washed walls, courtyards, and patios. These vernacular strategies have great potential for decreasing energy consumption in modern buildings [30]. In addition, Fernandes et al. [31] investigated the thermal performance and comfort of vernacular buildings in Egypt and Portugal. The results showed the correlation between the thermal performance of vernacular buildings and human comfort perception in two different case studies located in the Mediterranean climate. It was revealed that the common passive techniques in both cases were different, based on the site selection. However, overall, vernacular passive strategies can be used to achieve indoor thermal comfort and reduce loads of mechanical systems. Kubota and Toe [32] investigated how passive cooling strategies in vernacular houses were used in modern houses to reduce energy consumption in Malaysia. They used experimental measurements in two traditional timber Malay houses and two traditional masonry Chinese shop houses, then they investigated indoor thermal environments and passive cooling techniques in the case studies. The results revealed that the indoor air temperature of rooms adjacent to courtyards was lower than the outdoor temperature by up to 5–6 ◦C during the day. In addition, the indoor air temperature of rooms was similar to the outdoor temperature at night. They determined an adaptive thermal comfort equation for hot-humid climates. The indoor operative temperature reached more than 80% comfort in the Malay houses and Chinese shop houses. Passive strategies in vernacular houses included night ventilation, roof and ceiling insulation, window and wall shading, and courtyards. Alrashed et al. [33] investigated the roles of Mashrabiyah, courtyards, and adobe construction for Dhahran, Guriat, Riyadh, Jeddah, and Khamis Mushait in Saudi Arabia. They designed a base and then calculated the electricity value of the houses adjusted with these passive strategies and materials. Their results revealed that in terms of energy saving, courtyards are not useful. Using Mashrabiyah can reduce energy consumption by 4% and 3%, and adobe can reduce energy consumption by 6% and 19%. Also in Chinese houses in a hot and humid climate, courtyard, patio, and semi-open spaces are used to create indoor thermal comfort [34]. Different types of courtyards of Chinese vernacular houses in a hot and humid climate perform different functions in improving indoor thermal comfort [35]. Another study indicated that using Shavadan spaces in traditional houses in a hot and humid climate can create thermal comfort and help to reduce cooling and heating loads [36]. Studies of passive strategies in vernacular houses in India revealed the relation of vernacular architectural features to thermal comfort conditions [13,37]. In addition, replacing rubble stone masonry with burnt clay brick masonry and stabilized soil block masonry was found to increase the embodied energy of the dwelling by 9.7 times (870%) and 2.8 times (182%), respectively [13]. Applying traditional materials, such as adobe, could be the best option in hot and humid climates [38]. Different parameters influence the thermal comfort of the individuals in closed environments. For instance, the value of insufficiency of clothing influences the thermal transaction between the human body and environment. In addition, the speed of the flaw (the appropriate amount of which is Buildings 2018, 8, 81 5 of 23 variable) and the amount of individual labor (which specifies the rhythm of metabolism) should be determined [39]. Mean radiant temperature was calculated in assessment of thermal comfort, which is the relationship between the radiant and room surfaces (floor, ceiling and walls) [39]. The two factors of relative humidity and air temperature have a great effect on an individual’s thermal comfort. A relative humidity less than 30% may result in dry skin, eye irritation, and breathing problems, while a relative humidity (RH) higher than 60% may result in an environment suitable for mold growth and allergic problems [40]. According to ISO 7730 [41], to assess thermal comfort the two indicators of PMV (Predicted Mean Vote) and PPD (Predicted Percentage of Dissatisfied) were determined and the dissatisfaction rate was expressed by percentage. PMV has different borders and each has a different meaning, as listed in Table1.

Table 1. The thermal comfort index PMV (Predicted Mean Vote) and its relationship to thermal sensitivity [41].

PMV Thermal Sensitivity +3 Hot +2 Warm +1 Slightly warm 0 Neutral −1 Slightly cool −2 Cool −3 Cold

In this index, the thermal sensitivity of the environment is divided across the range from hot to cold. The PMV value is determined using Equation (1).

−0.036M −3 PMV = (0.303e + 0.028). {(M − W) − 3.05 × 10 [5733 − 6.99(M − W) − PW

−5 −0.42[(M − W) − 5815] − 1.7 × 10 (5867 − Pa) − 0.0014M (34 − Ta) (1) −8 4 4 −3.96 × 10 . fcl[(Tcl + 273) − (Tr + 273) ] − fclhc(Tcl − Ta)} In which M = metabolic free energy production (w/m2), w = external work (w/m2), Pw = the partial pressure of water, fcl = the ratio of clothed/nude surface area, Tcl = clothing ◦ 2 surface temperature ( C), hcl = convective transfer coefficient (w/m K), and Tr = mean radiant temperature (◦C). Meanwhile, the PPD value is calculated according to the PMV, which is specified in Equation (2) [41]. PPD is predicted percentage dissatisfied. PPD indicated percentage of dissatisfy people of thermal comfort in indoor room.

4 4 PPD = 100 − 95e−(0.03353PMV +0.2179PMV ) (2)

Reviewing previous studies revealed that vernacular houses in hot and dry climates have used several strategies in order to create indoor thermal comfort. The performance of vernacular houses is better than that of modern houses. In vernacular houses materials with high thermal capacity, light colors, domed roofs, and wind catchers were used. Underground spaces and semi-open spaces are also used in vernacular houses in hot and dry climates. Courtyards create microclimates in vernacular houses and are very effective in creating indoor thermal comfort. Also, vegetation and water are used for increasing relative humidity. The iwan is a very important element in vernacular houses for the hot and dry climate in Iran. Previous studies have supported this idea and emphasized the effect of iwans on the indoor thermal comfort. However, previous studies on iwans with the approach of considering climate are either qualitative or descriptive. Buildings 2018, 8, 81 6 of 23

Their effect has not yet been studied quantitatively by numerical simulation or the implementation of fieldwork. The purpose of this study is to investigate the role of the iwan on the thermal comfort of a Buildingstalar 2018 room, 8, ofx FOR a traditional PEER REVIEW house in Shiraz, Iran. The effect of an attached iwan on the thermal condition6 of 23 of the selected room is determined by field measurement and numerical simulation. The full-scale significantexperiment effect is carriedof the iwan out using on the various summer sensors passive for the condition evaluation of of the the adjacent current conditiontalar is determined of the and buildingpresented as for well different as the validation periods of thea year. numerical simulation. Finally, the significant effect of the iwan on the summer passive condition of the adjacent talar is determined and presented for different 2. Caseperiods Study of a year.

2.Iwan Cases, Study as shown in Figure 1, are widely used in Iran’s traditional buildings for various climate conditions including hot and dry, cold, hot and humid, and mild and humid. Amongst all of the Iwans, as shown in Figure1, are widely used in Iran’s traditional buildings for various climate iwansconditions constructed including for traditional hot and dry, houses cold, hot in and Iran, humid, iwans and belonging mild and to humid. traditional Amongst houses all of in the Shiraz wereiwans selected constructed as the foriwan traditional is considered houses as in Iran,an architectural iwans belonging element to traditional evident houses in traditional in Shiraz werehouses of this selectedcity. To asmake the iwan the function is considered of the as aniwan architectural in traditional element buildings evident inobvious, traditional Figure houses 2 represents of this city. how the iwanTo make schematically the function alleviate of the iwans the in traditionalthermal conditions buildings obvious,in a traditional Figure2 representshouse in Shiraz. how the iwan schematicallyAmong the alleviatestraditional the houses thermal in conditions Shiraz, the in aManteghi traditional-N houseezhad in house Shiraz. was selected. The iwan of this houseAmong represents the traditional the most houses common in Shiraz, type of the iwan Manteghi-Nezhad amongst all traditional house was selected.houses of The the iwan city. The Manteghiof this- houseNezhad represents house thewas most a residential common type house of iwan built amongst in Qajar all traditional era (1870– houses1890). of The the city.building includesThe Manteghi-Nezhad a ground floor and house an wasunderground a residential floor. house The built house in Qajar has eraa flat (1870–1890).-roof iwan The with building two pillars includes a ground floor and an underground floor. The house has a flat-roof iwan with two pillars and and it opens on a central courtyard, as shown Figure 3. it opens on a central courtyard, as shown Figure3.

FigureFigure 2. Strategies 2. Strategies for for creating creating thermal thermal comfortcomfort in in traditional traditional houses houses in Shiraz, in Shiraz, Iran. Iran.

Buildings 2018, 8, x FOR PEER REVIEW 6 of 23 significant effect of the iwan on the summer passive condition of the adjacent talar is determined and presented for different periods of a year.

2. Case Study Iwans, as shown in Figure 1, are widely used in Iran’s traditional buildings for various climate conditions including hot and dry, cold, hot and humid, and mild and humid. Amongst all of the iwans constructed for traditional houses in Iran, iwans belonging to traditional houses in Shiraz were selected as the iwan is considered as an architectural element evident in traditional houses of this city. To make the function of the iwan in traditional buildings obvious, Figure 2 represents how the iwan schematically alleviates the thermal conditions in a traditional house in Shiraz. Among the traditional houses in Shiraz, the Manteghi-Nezhad house was selected. The iwan of this house represents the most common type of iwan amongst all traditional houses of the city. The Manteghi-Nezhad house was a residential house built in Qajar era (1870–1890). The building includes a ground floor and an underground floor. The house has a flat-roof iwan with two pillars and it opens on a central courtyard, as shown Figure 3.

Buildings 2018, 8, 81 7 of 23 Figure 2. Strategies for creating thermal comfort in traditional houses in Shiraz, Iran.

Buildings 2018, 8, x FOR PEER REVIEW 7 of 23

Figure 3. Iwan and talar of the Manteghi-Nezhad house, Shiraz. Figure 3. Iwan and talar of the Manteghi-Nezhad house, Shiraz.

Table 2 shows typical traditional houses in Shiraz, which were selected randomly and the patternTable of 2spaces shows and typical their traditional interconnections houses inare Shiraz, represented. which were selected randomly and the pattern of spaces and their interconnections are represented.

Buildings 2018, 8, x FOR PEER REVIEW 8 of 23 BuildingsBuildings 20182018,, , 8 8,, , x xx FOR FORFOR PEER PEERPEER REVIEW REVIEWREVIEW 88 of of 23 23 Buildings 2018, 8, x FOR PEER REVIEW 8 of 23 BuildingsBuildingsBuildings2018, 201820188, 81,, 88,, xx FORFOR PEERPEER REVIEWREVIEW 88 ofof 2323 8 of 23 BuildingsBuildingsBuildingsBuildings 2018 2018 20182018,, , 8, 8 8,8, , x, x x x FOR FOR FORFOR PEER PEER PEERPEER REVIEW REVIEW REVIEWREVIEW 888 8 of of ofof 23 23 2323 TableTable 22... TTypicalypical traditionaltraditional houseshouses inin Shiraz,Shiraz, whichwhich werewere selectedselected randomlyrandomly... TTThehe patternpattern ofof spacesspaces andand theirtheir interconnectionsinterconnections areare represented.represented. TableTableTable 22 2.. .TT Typicalypicalypical traditionaltraditional traditional houseshouses houses inin in Shiraz,Shiraz, Shiraz, whichwhich which werewere were selectedselected selected randomlyrandomly randomly.. .TT Thehehe patternpattern pattern ofof of spacesspaces spaces andand and theirtheir their interconnectionsinterconnections interconnections areare are represented.represented. represented.

ResidenceResidenceTableTableTableTableTable 2. Typical 2 2 2.2. . T. T TTypicalypicalypicalypical traditional traditional traditional traditionaltraditionalIwanIwanIwanhouses inin inhouses houses houseshouses PlanPlan inin in inin Shiraz, Shiraz, Shiraz,Shiraz, which which whichwhich were were werewere Plan Plan selected selected selectedselected selected randomly randomly randomlyrandomly randomly... . T. T TTheheResidenceheheResidence The pattern pattern patternpattern pattern of of ofof spaces spaces spacesspaces of spaces and and andand theirIwan theirIwan Iwantheirtheir and interconnections interconnectionsinterconnections interconnectionstheir ininin PlanPlan interconnections are are areare represented. represented. represented.represented. are represented.PlanPlan ResidenceResidenceResidence IwanIwanIwan in inin Plan PlanPlan PlanPlanPlan ResidenceResidenceResidence IwanIwanIwan in inin Plan PlanPlan PlanPlanPlan ResidenceResidenceResidenceResidenceResidence IwanIwanIwanIwan in in inin Plan Plan PlanPlan PlanPlanPlanPlan ResidenceResidenceResidenceResidence IwanIwanIwanIwan in in inin Plan Plan PlanPlan PlanPlanPlanPlan

11 ZinatolmolkZinatolmolk 99 MansouryMansoury 111 ZinatolmolkZinatolmolkZinatolmolk 999 MansouryMansouryMansoury 111 1 1ZinatolmolkZinatolmolkZinatolmolkZinatolmolk Zinatolmolk 9999 9 MansouryMansoury MansouryMansoury

22 YazdaniYazdani 1010 PourhasanPourhasan 222 2YazdaniYazdaniYazdani Yazdani 101010 PourhasanPourhasanPourhasan 222 2 YazdaniYazdaniYazdaniYazdani 10101010 PourhasanPourhasanPourhasanPourhasan

33 3FotouhabadiFotouhabadi Fotouhabadi 111111 Afsharian Afsharian 333 FotouhabadiFotouhabadiFotouhabadi 111111 AfsharianAfsharianAfsharian 333 3 FotouhabadiFotouhabadiFotouhabadiFotouhabadi 11111111 AfsharianAfsharianAfsharianAfsharian

Buildings 2018, 8, 81 9 of 23

BuildingsBuildingsBuildings 2018 20182018,, , 8 88,, , x xx FOR FORFOR PEER PEERPEER REVIEW REVIEWREVIEW 999 of ofof 23 2323 BuildingsBuildingsBuildingsBuildings 2018 20182018 2018,, , 8 ,88 ,8, , x ,xx x FOR FORFOR FOR PEER PEERPEER PEER REVIEW REVIEWREVIEW REVIEW 999 9 of ofof of 23 2323 23 BuildingsBuildings 2018 2018, ,8 8, ,x x FOR FOR PEER PEER REVIEW REVIEW Table 2. Cont. 99 of of 23 23

44 ShahvaranShahvaran 1212 AtroushAtroush 444 4 ShahvaranShahvaranShahvaranShahvaran 12121212 AtroushAtroushAtroushAtroush 44 4ShahvaranShahvaran Shahvaran 121212 Atroush Atroush

55 NahadNahad roshan Nahadroshan 1313 MontazaryMontazary 555 5 NahadNahadNahad5Nahad roshan roshan roshanroshan 13131313 MontazaryMontazaryMontazary Montazary 55 NahadNahad roshan roshanroshan 1313 MontazaryMontazary

66 6NadafNadaf Nadaf 141414 Fili FiliFili 666 6 NadafNadafNadafNadaf 14141414 FiliFiliFiliFili 66 NadafNadaf 1414 FiliFili

Buildings 2018, 8, 81 10 of 23

BuildingsBuildings 20182018,, 88,, xx FORFOR PEERPEER REVIEWREVIEW 1010 ofof 2323 BuildingsBuildings 20182018,,, 88,,, xxx FORFORFOR PEERPEERPEER REVIEWREVIEWREVIEW 1010 ofof 2323 BuildingsBuildingsBuildings 2018 2018 2018, ,8 8, ,8x x, FORx FOR FOR PEER PEER PEER REVIEW REVIEW REVIEW Table 2. Cont. 101010 of of of23 23 23

77 RazmjouieRazmjouie 1515 ArdakaniArdakani 77 RazmjouieRazmjouie 1515 ArdakaniArdakani 77 7 7RazmjouieRazmjouieRazmjouie Razmjouie 15151515 ArdakaniArdakani ArdakaniArdakani

88 SadaghatiSadaghati 1616 SarrafSarraf 88 8SadaghatiSadaghati Sadaghati 161616 SarrafSarraf 88 8 SadaghatiSadaghatiSadaghati 161616 SarrafSarrafSarraf

1717 ManteghiManteghi17 Manteghi-Nezhad--NezhadNezhad 1717 ManteghiManteghi--NezhadNezhad 171717 ManteghiManteghiManteghi-Nezhad-Nezhad-Nezhad

BuildingsBuildings 2018 2018, 8, ,x 8 FOR, x FOR PEER PEER REVIEW REVIEW 11 of11 23of 23 Buildings 2018, 8, 81 11 of 23 TheThe talar talar room room is placedis placed at atthe the back back of ofthe the iwan iwan, which, which is ais considerablea considerable space space in inthe the building. building. TheThe room room has has grille grille windows windows which which are are made made of ofstone stone and and glass glass, equipped, equipped with with sashes sashes capable capable of of The talar room is placed at the back of the iwan, which is a considerable space in the building. openingopening and and closing closing the the windows. windows. It hasIt has doors doors that that connect connect to torooms rooms on on both both sides. sides. The The plan plan of ofthe the The room has grille windows which are made of stone and glass, equipped with sashes capable of groundground floor floor and and underground underground sections sections of ofthe the house house are are shown shown in inFigure Figure 4, in4, inwhich which the the place place of ofthe the opening and closing the windows. It has doors that connect to rooms on both sides. The plan of the iwaniwan and and talar talar room room in inground ground floor floor ar ear markede marked by by the the hatched hatched area. area. ground floor and underground sections of the house are shown in Figure4, in which the place of the iwan and talar room in ground floor are marked by the hatched area.

FigureFigure 4. 4.Plans4. Plans of ofthe the underground underground floor floorfloor and and ground ground floor floorfloor of ofthe the Manteghi Manteghi-NezhadManteghi-Nezhad-Nezhad house house and and the the sectionssections of ofthe the talar talar room room and and iwan. iwan.iwan.

MicroclimateMicroclimate Study Study ◦ ◦ ShirazShiraz is located is located between between 29.39 29.39° north° north latitude latitude and and 52.35 52.35 ° east° east longitude. longitude. According According According to toFigure to Figure Figure 5, 55,, thethe climate climate of ofShiraz Shiraz is ishot hot and and dry. dry.dry. Shiraz ShirazShiraz is isissituated situatedsituated 1486 14861486 m mmabove aboveabove sea seasea level. level.level. The TheThe monthly monthlymonthly normal normal climateclimate of of Shiraz Shiraz is isgiven given in inTable Table 3.3 3Based.. BasedBased on onon Table TableTable 3,3 ,3,June, June, June, July, July, July, August August, August, and and, and September September September are are are the the the warmestwarmest months months of ofthe thethe year. year.year.

FigureFigure 5. Climate 5.5. Climate divisions divisions of ofIran Iran [42] [[42]42. ].. Buildings 2018, 8, 81 12 of 23 Buildings 2018, 8, x FOR PEER REVIEW 12 of 23

TableTable 3. 3.Average Average weather weather conditions conditions in inShiraz, Shiraz, IranIran (2000–2016)(2000–2016) ( (fromfrom the the Meteorological Meteorological Organization Organization of ofIran Iran).).

Average Min Average Max Average Average Average Average Dry Min Average Max Average Month Relative Relative Relative Wind Wind Speed Bulb Temp. (°C) Dry Bulb Temp. (°C) Dry Bulb Temp. (°C) Humidity (%) Humidity (%) Humidity (%) Speed (m/s) Direction (Degrees) January 6 0 12 62 35 86 1.3 117 February 7 1 13 57 33 82 2.2 136 March 12 5 18 48 27 71 2.3 144 April 17 9 24 40 23 61 2.8 171 May 23 15 30 29 16 46 3.3 198 June 28 19 36 19 9 34 2.7 179 July 30 21 37 22 13 36 2.9 182 August 29 20 37 24 11 40 2.4 155 September 25 14 34 23 9 42 1.7 111 October 19 9 27 31 11 57 1.9 126 November 13 5 21 41 20 60 1.3 112 December 6 1 13 61 38 82 1.7 110 Buildings 2018, 8, x FOR PEER REVIEW 13 of 23 Buildings 2018, 8, 81 13 of 23 Buildings 2018, 8, x FOR PEER REVIEW 13 of 23

3. Numerical Simulation 3.3. Numerical Numerical Simulation Simulation DesignBuilder software [43] with the Energy Plus engine was used for the simulation of the ManteghiDesignBuilderDesignBuilder-Nezhad house. softwaresoftware The [thermal[43]43] with exchange the Energy Energy between Plus Plus theengine engine spaces was was of used the used b foruildi for theng, the simulation iwan, simulation talar ,of and ofthe thesurroundingManteghi Manteghi-Nezhad-Nezhad rooms hwereouse. house. simulated. The thermal The thermalAlso, exchange the exchangeadjacent between buildings between the spaces which the of spaces thecontribute buildi of theng, to building, iwan,creating talar shade iwan,, and talar,weresurrounding considered and surrounding rooms as block were rooms components simulated. were simulated.Also, and somethe adjacent parts Also, of thebuildings the adjacent neighboring which buildings contribute houses which and to undergroundcreating contribute shade to creatingspaceswere consideredbelow shade the were talaras block considered and components surrounding as block and rooms components some were parts assumed andof the some neighboring to be parts adiabatic. of houses the neighboringTwo and scenarios underground houses were andsimulatedspaces underground below using the this talar spaces software. and below surrounding In the the talar first rooms and case, surrounding were the current assumed rooms situation to be were adiabatic. was assumed simulated Two to scenarios accordingbe adiabatic. were to TwoFiguresimulated scenarios 6. In usingthe were second this simulated software.case, the using talar In this the was software.first considered case, In the the without current first case, the situation theiwan current, as wa showns situation simulated in Figure was according simulated 7. to accordingFigure 6. In to the Figure second6. In case, the the second talar case,was considered the talar was without considered the iwan without, as shown the in iwan, Figure as shown7. in Figure7.

Figure 6. Simulation of the talar with an iwan (case 1). Figure 6. Simulation of the talar with an iwan (case 1). Figure 6. Simulation of the talar with an iwan (case 1).

Figure 7.7. Simulation of the talar without an iwan (case 2).2). Figure 7. Simulation of the talar without an iwan (case 2). The exterior and interior walls and roof of the building, which were made of traditional The exterior and interior walls and roof of the building, which were made of traditional materials, materialsThe, were exterior simulated and interior by the wallsDesignBuilder and roof software of the buildingbased on, whichlayers with were the made current of traditionalstatus. In were simulated by the DesignBuilder software based on layers with the current status. In Table4, Tablematerials 4, forms, were of simulatedthe layers, by the the thickness DesignBuilder and density software of the basedir material, on layers their with specific the current heat, and status. their In forms of the layers, the thickness and density of their material, their specific heat, and their thermal thermalTable 4, conductivity forms of the are layers, presented. the thickness and density of their material, their specific heat, and their conductivity are presented. thermalThe dconductivityoors and frames are presented. of the windows and sashes are made of wood and the windows above the The doors and frames of the windows and sashes are made of wood and the windows above doors Theare dmadeoors andof common frames of glass the windowswith a thickness and sashes of 3are mm. made To offind wood the and extent the towindows which theabove iwan the the doors are made of common glass with a thickness of 3 mm. To find the extent to which the iwan passivelydoors are affect mades theof common environment glass ofwith the a talarthickness room of in 3 amm. normal To find situation, the extent no heating to which or thecooling iwan passively affects the environment of the talar room in a normal situation, no heating or cooling system syspassivelytem was affect considereds the environment for the talar of theand talar surrounding room in arooms normal in situation, the software no . heating Ventilation or cooling was was considered for the talar and surrounding rooms in the software. Ventilation was considered consideredsystem was normally. considered The fornumber the talarof persons and surrounding using the talar rooms room in was the considered software. Vasentilation the average was normally. The number of persons using the talar room was considered as the average number of numberconsidered of members normally. in Thean Iranian number family of persons, four people using [44]the ,talar and roomother roomswas considered such as bedroom as the averages were members in an Iranian family, four people [44], and other rooms such as bedrooms were considered to considerednumber of tomembers have a one in an-person Iranian capacity. family ,Detailed four people information [44], and is other presented rooms in such Table as 5.bedroom s were haveconsidered a one-person to have capacity. a one-person Detailed capacity. information Detailed is presented information in Tableis presented5. in Table 5. BuildingsBuildings 20182018,, 88,, 81x FOR PEER REVIEW 1414 ofof 2323

Table 4. Layers of floors, external wall, and internal wall in DesignBuilder software (National Table 4. Layers of floors, external wall, and internal wall in DesignBuilder software (National Building Building Regulations of Iran Building Code under the appellation of Issue 19, 2010 third edition Regulations of Iran Building Code under the appellation of Issue 19, 2010 third edition building and building and housing research center publishing). housing research center publishing). Number Thickness Conductivity Specific Heat Density Detail of Wall and Floor Layer Detail of Wall Numberof Layers Thickness(m) Conductivity(W/m-K) Specific(j/kg Heat-K) Density(kg/m3) Layer and Floor of Layers Plaster (m)0.01 (W/m-K)0.4 (j/kg-K)1000 (kg/m10003) External wall 3 Brick 0.47 0.72 840 1920 Plaster 0.01 0.4 1000 1000 External wall 3 BrickPlaster 0.470.02 0.720.4 8401000 19201000 Plaster 0.02 0.4 100 1000 3 Plaster 0.02 0.4 1000 1000 Internal wall Adobe 0.06 1.1 840 1770 - Plaster 0.02 0.4 100 1000 Plaster 0.02 0.4 1000 1000 Internal wall 3 Adobe 0.06 1.1 840 1770 PlasterThatch 0.020.01 0.41.1 1000840 10001500 Soil 0.02 1.1 840 1770 Thatch 0.01 1.1 840 1500 Ghoureh- 1 gel 0.12 1.1 840 1770 Soil 0.02 1.1 840 1770 Floor 7 Mat 0.003 0.19 2390 700 Ghoureh- 1 gel 0.12 1.1 840 1770 Wood Timber 0.03 0.19 2390 700 Floor 7 Mat 0.003 0.19 2390 700 Wood TimberAir 0.030.3 0.19- 2390- 700- AirLathing 0.30.02 -0.19 -2390 -700 1 A kind of concrete that is used inLathing the slope of roofs 0.02; instead 0.19of limestone, gypsum 2390 and debris 700 are used.1 A kind of concrete that is used in the slope of roofs; instead of limestone, gypsum and debris are used.

Table 5. Occupied area of rooms in DesignBuilder software. Table 5. Occupied area of rooms in DesignBuilder software. Name of Room Area (m2) Number of People Density (People/m2) 2 2 NameTalar of Room Area24.54 (m ) Number4 of People Density0.163 (People/m ) RoomTalar 1 11.7324.54 1 40.085 0.163 RoomRoom 1 2 22.1311.73 1 10.045 0.085 Room 2 22.13 1 0.045

Validation Validation For the validation of the DesignBuilder simulation software, information related to temperature and Forrelative the validationhumidity ofwere the collected DesignBuilder from 9 simulation:00 a.m. on software, 24 January information 2017 to 9:00 related a.m.to on temperature 2 February and2017 relative (10 days). humidity This were period collected included from the 9:00 coldest a.m. on days 24 January during 2017 to acco 9:00rding a.m. the on 2 meteorological February 2017 (10organization days). This of period Iran. includedThe interval the coldesttime for days the duringdata collection 2017 according was 20 the min meteorological. The location organization of the data oflogger Iran. is The shown interval in Figure time for 8. The the datameasurement collection was was taken 20 min. in Thethe center location of ofthe the talar data room logger and is the shown data inlogger’s Figure height8. The was measurement 0.8 m. was taken in the center of the talar room and the data logger’s height was 0.8 m.

FigureFigure 8.8. DataData logger for recording air temperature and humidity,humidity, asas wellwell asas itsits thethe locationlocation inin thethe talartalar room.room.

TheThe accuracy accuracy of of the the data data logger logger device device in measuring in measuring the temperature the temperature was ±0.5 was◦C and±0.5 its°C accuracy and its inaccuracy measuring in measuring the relative the humidity relative humidity was 3% for was temperatures 3% for temperatures between −between30 and +70−30 ◦andC. It+70 had °C the. It had the capacity to connect to a computer and data could be transferred to a PC. This data logger connected to computer as PC and it do not connect to laptop. After collecting related field data, they Buildings 2018, 8, 81 15 of 23

capacityBuildings 2018 to connect, 8, x FOR toPEER a computer REVIEW and data could be transferred to a PC. This data logger connected15 of to23 computer as PC and it do not connect to laptop. After collecting related field data, they were compared towere software compared data to for software the same data period for ofthe time. same Variation period of of time. temperature Variation and of temperature relative humidity and relative for the mentionedhumidity for period the mentioned is illustrated period in Figure is illustrated9. in Figure 9. According toto Figure9 9,, the the differencedifference between between the the field field data data and and simulation simulation for for temperature temperature was was 1.7%,1.7%, whichwhich waswas in in an an acceptable acceptable range. range. Also, Also, the the difference difference between between the the field field data data and and simulation simulation for relativefor relative humidity humidity was was 3.8%. 3.8%. Based Based on theon the agreements, agreements, the resultsthe results of the of thermalthe thermal performance performance of the of talarthe talar room ro usingom using the softwarethe software are calculatedare calculated in the in nextthe next section. section.

Figure 9.9. Comparison of the measured temperature, relative humidity and calculated temperature, relativerelative humidityhumidity forfor thethe centralcentral talartalar roomroom (24(24 JanuaryJanuary 09:0009:00 a.m.a.m. toto 22 FebruaryFebruary 09:0009:00 a.m.,a.m., 2017).2017).

4. Discussion 4. Discussion In this section, data related to simulation scenarios of the talar room at the Manteghi-Nezhad In this section, data related to simulation scenarios of the talar room at the Manteghi-Nezhad house in the two cases of considering the talar with an iwan and without an iwan are represented. In house in the two cases of considering the talar with an iwan and without an iwan are represented. Figure 10, the air temperature (Ta), radiant temperature (Tr), and relative humidity of the talar room In Figure 10, the air temperature (Ta), radiant temperature (Tr), and relative humidity of the talar with the iwan and without the iwan are illustrated over one year in order to distinguish the room with the iwan and without the iwan are illustrated over one year in order to distinguish the performance of the iwan during warm and cold months. performance of the iwan during warm and cold months. The indoor temperature and radiant temperature of both cases were less than the outdoor dry The indoor temperature and radiant temperature of both cases were less than the outdoor dry bulb temperature in the warm months (according Table 3, the warm months are June, July, August, bulb temperature in the warm months (according Table3, the warm months are June, July, August, and September). Furthermore, in the cold months Ta and Tr were higher than the outdoor dry bulb and September). Furthermore, in the cold months Ta and Tr were higher than the outdoor dry bulb temperature. This was due to the materials of the house, which responded well in both warm and temperature. This was due to the materials of the house, which responded well in both warm and cold cold months. The figure shows that the indoor temperature and radiant temperature of both cases were less than the outdoor dry bulb temperature in the warm months. This was because of the talar room, which was located on the south side of the courtyard with the backside towards the sun and with sufficient shadow. In the warm months, the average air temperature of the talar room with the Buildings 2018, 8, 81 16 of 23 months. The figure shows that the indoor temperature and radiant temperature of both cases were less than the outdoor dry bulb temperature in the warm months. This was because of the talar room, which was located on the south side of the courtyard with the backside towards the sun and with sufficient Buildings 2018, 8, x FOR PEER REVIEW 16 of 23 shadow. In the warm months, the average air temperature of the talar room with the iwan was 2.3 ◦C ◦ less thaniwan thewas outdoor 2.3 °C less temperature than the outdoor but the temperature average T buta of the the average talar room Ta of withoutthe talar room the iwan without was the 1.2 C. iwanFurthermore, was 1.2 °C. the average difference of Tr for the talar room with the iwan in comparison to the ◦ talar roomFurthermore, without the the iwan average was difference 0.4 C. This of Tr isfor because the talar more room shadowswith the iwan were in providedcomparison by to the the iwan. However,talar room in the without cold months, the iwan the was average 0.4 °C. This of air is temperaturebecause more ofshadows the talar were room provided without by the the iwan iwan. was ◦ However, in the cold months, the average of air temperature of the talar room without the iwan was 2.3 C higher than the outdoor temperature, but average of Ta of the talar room with the iwan was 1.7 ◦C2.3 higher °C higher than than the the outdoor outdoor temperature temperature, but because average the of talar Ta of roomthe talar without room with the the iwan iwan receives was 1.7 more °C higher than the outdoor temperature because the talar room without the iwan receives more sun sun radiation. radiation. Figure 10 illustrates that the talar room had the lowest relative humidity during the warm months, Figure 10 illustrates that the talar room had the lowest relative humidity during the warm lowermonths than 20%., lower The than relative 20%. The humidity relative in humidity January, in February, January, and February December, and December was higher was compared higher to othercompared months ofto theothe yearr months as it of was thehigher year as thanit was 40%. higher than 40%.

FigureFigure 10. Comparison 10. Comparison of of the the average average temperature, temperature, radiant radiant temperature temperature,, and and relative relative humidity humidity of the of the talartalar room room for casefor case 1 and 1 and case case 2 during2 during different different months.months.

After the analysis of air temperature, mean radiant temperature (MRT) wind speed, and relativeAfter the humidity, analysis the ofvalue air of temperature, the PMV and PPD mean were radiant calculated temperature according Equations (MRT) wind (1) and speed, (2), as and relativerepresented humidity, in Figure the value 11. The of m theetabolic PMV rate and for PPD calculated were calculatedPMV and PPD according was assumed Equations to be 0.9. (1) The and (2), as representedmetabolic rate in Figureis the average 11. The of metaboliclight working, rate seating, for calculated relaxing, PMVsleeping and, and PPD reclining was assumed according to to be 0.9. Buildings 2018, 8, 81 17 of 23 Buildings 2018, 8, x FOR PEER REVIEW 17 of 23

ISOThe metabolic7730 [41]. rateAlso is, the the clo averagething oflevel light was working, assumed seating, to be relaxing,0.5 according sleeping, to ISO and 7730 reclining [41] for according typical summerto ISO 7730 indoor [41]. clothing. Also, the clothing level was assumed to be 0.5 according to ISO 7730 [41] for typical summerAcco indoorrding to clothing. previous studies, thermal comfort can be evaluated by the PMV index. Figure 11 showsAccording the variation to previous of the PMV studies, of the thermal talar room comfort for canthe betwo evaluated cases—with by the an PMViwan index.and without Figure an11 iwanshows. Based the variation on Figure of the11, PMVthe thermal of the talarsensitivity room forof the talar twocases—with room in both an cases iwan in and January, without February an iwan., andBased December on Figure was 11, cold. the thermal The PMV sensitivity index in of May, the talar June, room September in both, casesand October in January, was February, nearly zero and, whichDecember was wasvery cold. appropriate The PMV, and index the in thermal May, June, sensitivity September, of July and and October August was was nearly slightly zero, warm. which wasFor casevery 1 appropriate, in the warm and months the thermal, the PMV sensitivity index was of Julyless andthan August that of wascase slightly2. Also, warm.the PMV For of case case 1 2 in was the lesswarm than months, that of the case PMV 1 in index the cold was months. less than The that d ofifference case 2. Also,of the the PMV PMV index of case between 2 was case lesss than 1 and that 2 wasof case 2.8% 1 in because the cold of months. the different The difference air temperature of the PMV and radiant index between temperature cases 1values and 2, waswhich 2.8% are because shown inof Figure the different 10. air temperature and radiant temperature values, which are shown in Figure 10. According to the PMV index, the PPD can be calculated. Figure Figure 1111 showsshows the percentage of dissatisfaction of of the the residents residents in in the talar for both cases during various months. It It can can be be seen that during warm monthsmonths thethe PPDPPD index index was was lower lower than than that that during during cold cold months. months. The The lowest lowest value value of the of thedissatisfaction dissatisfaction index index belongs belongs to May, to May, June, June, July, September,July, September and October,, and October being, lessbeing than less 25%. than For 25%. the Fortalar the room talar with room an with iwan, an this iwan shows, this that shows in warmthat in months warm months the PPD the was PPD reduced. was reduced. ItIt must bebe notednoted that, that, in in reality, reality, in in Manteghi-Nezhad Manteghi-Nezhad house, house, the the talar talar room room with with a v forma v form was usedwas usedduring during the warm the warm months. months. According According to Figure to 11Figure, the iwan11, the was iwan an important was an important element for element achieving for achievingthermal comfort thermal in comfort the talar in room the talar during room the during warm months.the warm months.

Figure 11. Annual variation of PMV and PPD of the talar room with for case 1 and case 2. Figure 11. Annual variation of PMV and PPD of the talar room with for case 1 and case 2.

The monthly averages of the PMV and PPD indexes in both cases during the warm months (JuneThe to September) monthly averages are shown of the in PMVFigure and 12. PPD As shown, indexes the in bothPMV cases of case during 1 was the 0.5 warm less than months the PMV (June ofto case September) 2 in July, are August, shown September in Figure 12, and. As October shown,, thewhereas PMV it of provided case 1 was comfortable 0.5 less than condition the PMVs for of thecase occupants. 2 in July, August,Based on September, Figure 12, andthe difference October, whereas between it the provided PMV index comfortable of the talar conditions room with for thean iwan and that without an iwan was 62.5%. Buildings 2018, 8, 81 18 of 23 occupants.Buildings 2018 Based, 8, x FOR on PEER Figure REVIEW 12, the difference between the PMV index of the talar room with an18 iwan of 23 and that without an iwan was 62.5%. The average PPD index of the talar for thethe twotwo casescases duringduring thethe warmwarm monthsmonths is presentedpresented in Figure 1212.. The results show that dissatisfaction rate of case 1 was less than thatthat ofof casecase 22 duringduring thethe warmwarm months.months. TheThe PPD PPD of of the the talar talar room room with with an an iwan iwan decreased decrease byd 14%by 14% in comparison in comparison with with the talar the roomtalar room without without an iwan. an iwan. The relevant values of PMV and PPD of thethe talartalar roomroom withwith anan iwaniwan ascertainedascertained thatthat thethe goodgood performanceperformance of the iwaniwan couldcould createcreate moremore shadows.shadows. Thus, the iwan in thethe southsouth orientationorientation of thethe courtyardcourtyard isis anan effectiveeffective element element in in the the Manteghi-Nezhad Manteghi-Nezhad house house to reduceto reduce heat, heat especially, especially during during the warmthe warm months. months.

Figure 12.12. Comparison of PMV and PPD of the talar room for cases 1 and 2 during the warm months.months.

InIn orderorder toto analyzeanalyze thethe indoor indoor air air temperature, temperature, relative relative humidity, humidity and, and radiant radiant air air temperature temperature in detail,in detail a representative, a representative day duringday during the hot the months hot months was selected. was selected. According According to Figure to 13Figure, the selected 13, the variablesselected variables were compared were compared for case 1 for and case case 1 2and to findcase out2 to thefind overall out the thermal overall conditions thermal conditions that the iwan that canthe provideiwan can inside provide the talarinside room. the talar The resultsroom. The of indoor results air of temperature indoor air temperature and radiant airand temperature radiant air showedtemperature that theshowed iwan that could the significantly iwan could affect significantly the overall affect indoor the overall conditions indoor in case conditions 1. The difference in case 1. betweenThe difference the indoor between air temperature the indoor air and temperature the outdoor and air the temperature outdoor a inir temperature the afternoon in was the measuredafternoon aswas the measure highestd value as the for highest the talar value with for the the iwan. talar Thewith indoor the iwan air.temperature The indoor air at 4:00temperature p.m. was at 36 4◦:00C whilep.m. was the 36 outdoor °C while air the temperature outdoor air was temperature more than was 41 ◦ moreC. The than difference 41 °C. The for difference radiant air for temperature radiant air wastemperature higher than was thehigher indoor than air the temperature, indoor air temperature where it rose, where up to it 6 ◦roseC at up 4:00 to p.m.6 °C at This 4:00 was p.m due. This to thewas shadow due to caused the shadow by the iwancaused projection by the atiwan the projection southern direction at the southern of house. direction Comparison of house. of the resultsComparison during of the the nighttime results during and the the early nighttime morning and showed the early a smallmorning difference showed between a small thedifferen indoorce andbetween outdoor the indoor air temperatures and outdoor in bothair temperature cases. Thiss was in both due cases. to the This absence was of due sun to radiation. the absence Even of sun the differenceradiation. of Even air temperature the difference between of air cases temperature 1 and 2 was between less than case 1s ◦1C. and This 2 showswas less that than the iwan1 °C. could This effectivelyshows that reduce the iwan the air could temperature effectively as well reduce as the the radiant air tempe air temperaturerature as wellduring as thethe morning radiant and air thetemperature afternoon during times. the morning and the afternoon times. According to Figure 1313,, thethe relativerelative humidityhumidity in both cases was between 17% and 29% and thethe difference waswas trivial.trivial. Thus, it can be declared that the iwan could not affectaffect relative humidity in the indoorindoor environment.environment. According to the results, the relativerelative humidityhumidity in thethe eveningevening waswas higherhigher thanthan thatthat inin earlyearly morning.morning. This was due to thethe evaporation of water inin thethe courtyard,courtyard, especiallyespecially in thethe afternoon when thethe solarsolar radiationradiation waswas intensive.intensive. Table6 6 presents presents the the comparison comparison betweenbetween differentdifferent airair temperatures,temperatures, thethe PMV,PMV, and and thethe PPDPPD forfor both cases in in a a representative representative day. day. According According to to the the results, results, the the maximum maximum difference difference between between thethe air airtemperature temperature and and radiant radiant air temperature air temperature of case of casess 1 and 1 and2 occurred 2 occurred at 3:00 at 3:00p.m. p.m. in the in afternoon. the afternoon. The Theresults results show show that iwan that iwancould could decrease decrease the indoor the indoor air temperature air temperature up to 3up °C towhere 3 ◦C the where same the amount same amountof solar radiation of solar radiation was received was receivedin the afternoon. in the afternoon. The average The indoor average air indoortemperature air temperature and radiant and air radianttemperature air temperature for 24 h indicates for 24 h indicates that the thattalar the with talar the with iwan the iwancould could provide provide a better a better temperature temperature in incomparison comparison with with the the talar talar without without the theiwan iwan.. The Thedifference difference between between air temperatures air temperatures was more was more than 1 °C through the day. As a consequence, the PMV for case 1 was 1.1, which was better than case 2 with a PMV of 1.3. The Predicted Percentage of Dissatisfaction (PPD) for both cases showed that case 1 with the iwan had better thermal condition in 24 h. Based on the results, the PPD in case 1 was 9% less than that for case 2. Buildings 2018, 8, 81 19 of 23 than 1 ◦C through the day. As a consequence, the PMV for case 1 was 1.1, which was better than case 2 with a PMV of 1.3. The Predicted Percentage of Dissatisfaction (PPD) for both cases showed that case 1 with the iwan had better thermal condition in 24 h. Based on the results, the PPD in case 1 was 9% less Buildingsthan that 2018 for, 8, case x FOR 2. PEER REVIEW 19 of 23

Figure 13 13.. Comparison of the air temperature, temperature, radiant temperature temperature,, and relative humidity of the talar room for cases 1 and 2 on 29 July, Shiraz,Shiraz, Iran.Iran.

Comparison of of results results for for the the selected selected scenarios scenarios ascertain ascertain that the that iwan the asiwan an architectural as an architectural element elementin traditional in traditional houses could houses significantly could significantly reduce indoor reduce air temperature indoor air temperature and radiant temperature, and radiant temperatureespecially in,the especially afternoon in when the afternoon a high amount when of a solar high radiation amount penetrates of solar rathediation buildings. penetrates As a result, the buildings.better thermal As a comfort result, canbetter be thermal achieved comfort according can to be the achieved results ofaccording PMV and to PPD the forresults the currentof PMV study. and PPD for the current study. Thus, this study recommends further studies on the implementation of iwans in the new development of housing in the same microclimate for the provision of better thermal conditions as well as for saving energy in residential buildings.

Buildings 2018, 8, 81 20 of 23

Thus, this study recommends further studies on the implementation of iwans in the new development of housing in the same microclimate for the provision of better thermal conditions as well as for saving energy in residential buildings.

Table 6. Comparison of average thermal conditions of the talar room for cases 1 and 2 on 29 July, Shiraz, Iran.

Thermal Average 8:00 Average 12:00 Case 3:00 p.m. Average 24 h Conditions a.m.–8:00 p.m. a.m.–8:00 a.m. 1 35.7 31.8 24.9 28.4 T (Co) a 2 38.2 33.6 25.2 29.5 1 35.1 31.6 25.4 28.5 T (Co) r 2 37.8 33.5 26 29.8 ◦ Toutdoor ( C) 39.8 35.3 26.3 30.8 1 2.9 1.8 −0.09 1.1 PMV 2 3.8 2.39 0.03 1.3 1 100 67 5 32 PPD (%) 2 100 91 5 41

5. Conclusions The iwan has been used in hot and dry climates in many traditional houses in different forms and with various materials. The thermal comfort of a talar in a traditional house in Shiraz was studied for the two cases of the adjoined iwan with and without iwan. According to the results of field measurements and simulations, the following outcomes are specified. (1) The average indoor temperature of the talar during the year was about 3.9 ◦C higher than the outdoor temperature in the case of the iwan with a ceiling. The indoor temperature of the talar room with an iwan without a ceiling was 1% higher than that of the talar room with the iwan having ceiling over the course of one year. The difference between radiant and operative temperature in the two cases was very low. (2) The relative humidity in the talar room in both cases was below 20% in June, July, August, and September, while it was between 20% and 40% in October, November, March, April, and May. The relative humidity of the talar room in January, February, and December was higher than 40%. (3) The talar in the case of the iwan with a ceiling was completely appropriate to fulfill the thermal comfort situation in June, July, September, and October. Furthermore, in August and September, it was in the range of warm and in December it was relatively cool. It was not under the comfort range in other months of the year, although a heating device was necessary. In the case of the iwan without a ceiling, the situation was not in the comfort range, especially in the summer months. However, the conditions improved slightly in the cold months. (4) Based on the calculated PMV index, the talar with the iwan without a ceiling was 8% better during the year, but for warm months the talar with the iwan with a ceiling was 42% better than the talar with the iwan without a ceiling. (5) In terms of the PPD index, the dissatisfaction rate in the case of the iwan with a ceiling was below 20% in June, July, September, and October, while the dissatisfaction index was about 40% in the two months of August and September. The dissatisfaction rate was poor for the cold months of the year. The PPD for the talar with an iwan with a ceiling was 18% better than that for the iwan without a ceiling during warm months. (6) The analyses of indoor thermal conditions for a representative day ascertained that the case with the iwan could significantly reduce the indoor air temperature. According to the results, the difference of indoor air temperature between the selected scenarios reached up to 3 ◦C in the afternoon, when high amount of solar intensity hit the building. Buildings 2018, 8, 81 21 of 23

(7) According to the results, the iwan contributes to the thermal satisfaction inside traditional buildings. Thus, it is recommended that further studies be carried out in order to apply this architectural element to the development of new residential buildings for the same microclimate.

Author Contributions: Conceptualization, J.S.; Methodology, J.S.; Software, J.S.; Validation, M.Y., A.H.; Formal Analysis, J.S.; Investigation J.S., M.Y., A.H.; Resources, M.Y., A.H.; Data Curation, J.S., M.Y., A.H.; Writing-Original Draft Preparation, J.S., M.Y., A.H.; Writing-Review & Editing, M.Y., A.H.; Visualization, J.S.; Supervision, M.Y., A.H., Project Administration, J.S. Funding: This research received no external funding Conflicts of Interest: The authors declare no conflicts of interest.

References

1. Afshari, H. Design Fundamentals in the Hot and Humid Climate of Iran: The Case of Khoramshahr. Asian Cult. Hist. 2012, 4, 65. [CrossRef] 2. Bodach, S.; Lang, W.; Hamhaber, J. Climate responsive building design strategies of vernacular architecture in Nepal. Energy Build. 2014, 81, 227–242. [CrossRef] 3. Chávez, J.R.G.; Melchor, F.F. Application of Combined Passive Cooling and Passive Heating Techniques to Achieve Thermal Comfort in a Hot Dry Climate. Energy Procedia 2014, 57, 1669–1676. [CrossRef] 4. Sarkar, A. Study of Climate Responsive Passive Design Features in Traditional Hill Architecture of Khyah Village in Hamirpur, Himachal Pradesh, India Indoor Thermal Comfort. J. Inst. Eng. Ser. A 2013, 94, 59–72. [CrossRef] 5. Singh, M.K.; Mahapatra, S.; Atreya, S.K. Bioclimatism and vernacular architecture of north-east India. Build. Environ. 2009, 44, 878–888. [CrossRef] 6. Mashhadi, M.K. Comparison of Iranian and Turkish Traditional Architectures in Hot-Dry Climates, Eastern Mediterranean University (EMU). 2012. Available online: http://hdl.handle.net/11129/108 (accessed on 2 June 2018). 7. Baran, M.; Yıldırım, M.; Yılmaz, A. Evaluation of ecological design strategies in traditional houses in Diyarbakir, Turkey. J. Clean. Prod. 2011, 19, 609–619. [CrossRef] 8. Nematchoua, M.K.; Tchinda, R.; Orosa, J.A. Thermal comfort and energy consumption in modern versus traditional buildings in Cameroon: A questionnaire-based statistical study. Appl. Energy 2014, 114, 687–699. [CrossRef] 9. Soleymanpour, R.; Parsaee, N.; Banaei, M. Climate Comfort Comparison of Vernacular and Contemporary Houses of Iran. Procedia Soc. Behav. Sci. 2015, 201, 49–61. [CrossRef] 10. Motealleh, P.; Zolfaghari, M.; Parsaee, M. Investigating climate responsive solutions in vernacular architecture of Bushehr city. HBRC J. 2016.[CrossRef] 11. Priya, R.S.; Sundarraja, M.C.; Radhakrishnan, S.; Vijayalakshmi, L. Solar passive techniques in the vernacular buildings of coastal regions in Nagapattinam, TamilNadu-India—A qualitative and quantitative analysis. Energy Build. 2012, 49, 50–61. [CrossRef] 12. Dili, A.S.; Naseer, M.A.; Varghese, T.Z. Passive environment control system of Kerala vernacular residential architecture for a comfortable indoor environment: A qualitative and quantitative analyses. Energy Build. 2010, 42, 917–927. [CrossRef] 13. Praseeda, K.I.; Mani, M.; Reddy, B.V.V. Assessing Impact of Material Transition and Thermal Comfort Models on Embodied and Operational Energy in Vernacular Dwellings (India). Energy Procedia 2014, 54, 342–351. [CrossRef] 14. Mehr, S.M.; Noghrekar, A.H.; Mozaffar, F.; Taghdir, S. Architectural Space Affordance of Iranian Traditional Houses in Response to Levels of Physical and Spiritual Human Needs. Procedia Soc. Behav. Sci. 2015, 201, 342–351. [CrossRef] 15. Mohammadabadi, M.A.; Ghoreshi, S. Green Architecture in clinical centres with an approach to Iranian sustainable vernacular architecture (Kashan City). Procedia Eng. 2011, 21, 580–590. [CrossRef] 16. Manio˘glu,G.; Yılmaz, Z. Energy efficient design strategies in the hot dry area of Turkey. Build. Environ. 2008, 43, 1301–1309. [CrossRef] Buildings 2018, 8, 81 22 of 23

17. Soflaei, F.; Shokouhian, M.; Mofidi Shemirani, S.M. Traditional Iranian courtyards as microclimate modifiers by considering orientation, dimensions, and proportions. Front. Archit. Res. 2016, 225–238. [CrossRef] 18. ¸Serefhano˘gluSözen, M.; Gedík, G.Z. Evaluation of traditional architecture in terms of building physics: Old Diyarbakír houses. Build. Environ. 2007, 42, 1810–1816. [CrossRef] 19. Sedighi, E.; Yaghoubi, M.; Mousavi, S.M.; Siahpour, S. Thermal study of domed roofs in a traditional (the case of old Ganj-Alikhan bazaar in Kerman, Iran). Energy Sustain. Dev. 2017, 39, 67–81. [CrossRef] 20. Saljoughinejad, S.; Sharifabad, R.S. Classification of climatic strategies, used in Iranian vernacular residences based on spatial constituent elements. Build. Environ. 2015, 92, 475–493. [CrossRef] 21. Foruzanmehr, A. People’s perception of the loggia: A vernacular passive cooling system in . Sustain. Cities Soc. 2015, 19, 61–67. [CrossRef] 22. Foruzanmehr, A. Thermal comfort and practicality: Separate winter and summer rooms in Iranian traditional houses. Archit. Sci. Rev. 2016, 59, 1–11. [CrossRef] 23. Atrvash, A.; Fayaz, R. The effect of orsis on the air in the interior (Case Study: Zinat almolk of shiraz). Archit. Urban Plan. 2015, 9, 19–26. 24. Ryu, Y.; Kim, S.; Lee, D. The influence of wind flows on thermal comfort in the Daechung of a traditional Korean house. Build. Environ. 2009, 44, 18–26. [CrossRef] 25. Al-Hinai, H.; Batty, W.J.; Probert, S.D. Vernacular architecture of Oman: Features that enhance thermal comfort achieved within buildings. Appl. Energy 1993, 44, 233–258. [CrossRef] 26. Saadatian, O.; Haw, L.C.; Sopian, K.; Sulaiman, M.Y. Review of technologies. Renew. Sustain. Energy Rev. 2012, 16, 1477–1495. [CrossRef] 27. Toe, D.H.C.; Kubota, T. Comparative assessment of vernacular passive cooling techniques for improving indoor thermal comfort of modern terraced houses in hot–humid climate of Malaysia. Sol. Energy 2015, 114, 229–258. [CrossRef] 28. Singh, M.K.; Mahapatra, S.; Atreya, S.K. Thermal performance study and evaluation of comfort temperatures in vernacular buildings of North-East India. Build. Environ. 2010, 45, 320–329. [CrossRef] 29. Fernandes, J.; Pimenta, C.; Mateus, R.; Silva, S.M.; Bragança, L. Contribution of portuguese vernacular building strategies to indoor thermal comfort and occupants’ perception. Buildings 2015, 5, 1242–1264. [CrossRef] 30. Fernandes, J.; Mateus, R.; Bragança, L.; Júlio, J.; Correia da Silva, J.J. Portuguese vernacular architecture: The contribution of vernacular materials and design approaches for sustainable construction. Archit. Sci. Rev. 2015, 58, 324–336. [CrossRef] 31. Fernandes, J.E.P.; Debaieh, M.; Mateus, R.; Silva, S.M.; Bragança, L.; Gervásio, H.; Paper, C.; Malm, M.D.; Approach, A.I.; Cycle, L.C. Engineering, Thermal performance and comfort of vernacular earthen buildings in Egypt and Portugal. In Sostierra 2017, 3rd ed.; CRC Press: Boca Raton, FL, USA, 2017; pp. 95–100. 32. Kubota, T.; Toe, D.H.C. Application of passive cooling techniques in vernacular houses to modern urban houses: A case study of Malaysia. Procedia Soc. Behav. Sci. 2015, 179, 29–39. [CrossRef] 33. Climates, V.D.; Alrashed, F.; Asif, M.; Burek, S. The Role of Vernacular Construction Techniques and Materials for Developing Zero-Energy Homes in Various Desert Climates. Buildings 2017, 7, 17. [CrossRef] 34. Du, X.; Bokel, R.; Van Den Dobbelsteen, A. Building microclimate and summer thermal comfort in free-running buildings with diverse spaces: A Chinese vernacular house case. Build. Environ. 2014, 82, 215–227. [CrossRef] 35. Kubota, T.; Zakaria, M.A.; Abe, S.; Toe, D.H.C.; Hooi, D.; Toe, C. Thermal functions of internal courtyards in traditional Chinese shophouses in the hot-humid climate of Malaysia. Build. Environ. 2017, 112, 115–131. [CrossRef] 36. Hazbei, M.; Nematollahi, O.; Behnia, M.; Adib, Z. Reduction of energy consumption using passive architecture in hot and humid climates. Tunn. Undergr. Space Technol. 2015, 47, 16–27. [CrossRef] 37. Chandel, S.S.; Sharma, V.; Marwah, B.M. Review of energy ef fi cient features in vernacular architecture for improving indoor thermal comfort conditions. Renew. Sustain. Energy Rev. 2016, 65, 459–477. [CrossRef] 38. Beccali, M.; Strazzeri, V.; Germanà, M.L.; Melluso, V.; Galatioto, A. Vernacular and bioclimatic architecture and indoor thermal comfort implications in hot-humid climates: An overview. Renew. Sustain. Energy Rev. 2017, 1–11. [CrossRef] 39. De Dear, R.J.; Brager, G.S. Thermal comfort in naturally ventilated buildings: Revisions to ASHRAE Standard 55. Energy Build. 2002, 34, 549–561. [CrossRef] Buildings 2018, 8, 81 23 of 23

40. De Dear, R.J. A global database of thermal comfort field experiments. ASHRAE Trans. 1998, 104, 1141. 41. International Organization for Standardization. ISO 7730, Ergonomics of the Thermal Environment—Analytical Determination and Interpretation of Thermal Comfort Using Calculation of the PMV and PPD Indices and Local Thermal Comfort; International Organization for Standardization: Geneva, Switzerland, 2005. 42. Nasrollahi, F. Office Buildings Energy Efficient: Energy Efficiency with the Architectural Design; Berlin University: Berlin, Germany, 2015. 43. Designbuilder. Available online: https://www.designbuilder.co.uk/URL (accessed on 2 June 2018). 44. Iran Statistical Center. Census Results of General Population and Housing; Iran Statistical Center: Tehran, Iran, 2011.

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).