th Plea2004 - The 21 Conference on Passive and Low Energy Architecture. Eindhoven, The Netherlands, 19 - 22 September 2004 Page 1 of 1 Level of comfort in a traditional architectural typology: study the change to the level of comfort to know a gap-energy-need in a sustainable perspective Kristian Fabbri1 and Lamberto Tronchin2 1 Faculty of Architecture, University of Bologna, Via Cavalcavia, 55, 4023 Cesena FC, Italy E-MAIL: mailto:kristian.fabbri@arch.unibo.it 2 DIENCA - CIARM - University of Bologna Viale Risorgimento, 2 I-40136 Bologna – ITALY . URLs: http://www.ciarm.ing.unibo.it E-MAIL: mailto:tronchin@ciarm.ing.unibo.it ABSTRACT How could people in the past fulfil their standards of comfort until XIX century? What different levels of comfort standards do we need now compared to those in the past? What is the precise level of comfort in each land or country nowadays? In this article various comfort standards found in the XIX century architectural handbook, are compared with modern ones. A typical building located in the centre of Italy will be analysed comparing modern comfort standards to the original ones. This comparison highlights an increasing demand of energy for buildings only because comfort parameters are changed. This is a starting point for a speculation about a sustainable perspective. The tendency is now to have the same level of comfort parameters in every country (this is a result of actually trend of population growth and urbanization). Therefore the need for an increase of energy is only for “gap-incremental comfort”. The technical possibilities available increase energy requirements, and stimulate the use of high-energy technology systems. Also the comfort perception is modified. The answer for sustainable prospective is possible, studying traditional solution related to traditional habits and a different constructive plan, (respecting own history.) Another important issue is to learn from historical tradition about alternative methods of energy saving instead of relying and investing on high-tech solutions. Conference Topic: 8 Traditional Solution in suistainable perspective Keywords: Historical Architecture, Energy, Energy Saving, Comfort Standard INTRODUCTION The 70ies energetic crisis has highlighted the structural weaknesses of the western development model; this situation still lasts. The building methods are mainly responsible for these excessive energetic requirements. The study of architectonic solutions able to lower energetic consumption, and the use of alternative energies are getting more essential. Another aspect is the gradual globalisation of the models of development. Therefore even in Arabic and tropical countries conditioning systems are spreading, places where traditional architectonic conformation always took account of thermoregulation. H. Fathy’s study has deepened described these kinds of constructive techniques. The tendency is an impoverishment of architectonic knowledge and an irregular diffusion of air conditioning, centralized or independent. An example could be the exponential increase of the sales of air conditioners in last the 2 years and the Black out in Italy and USA. The two factors are not directly correlated but they are accomplices. The history of the modern architecture, from Corbusier, has been cutting ties with past constructive tradition, and has proposed undiversified architectonic model in different climatic contexts. Western cities and developing new cities (from New York to Frankfurt, from Singapore, Brasilia and Honk Kong) are showing the same architectonic constructive model. This kind of model applied to single building, appears out of contest and far from tradition. In this paper a typical building of 1800 located in central Italy (characterised by mild climatic conditions) is analysed. The energy requirement increment that there has been in the passage from a model of comfort adaptive to the natural environment and the current normative models are analysed. The historical- typological references are taken from L. Gambi text "The Rural house in the Romagna". The description of the building type and the constructive techniques are from "The Handbook of the architect" of Daniel Donghi published in 1933 who reassumes the XIX century constructive knowledge and sanitary requirements which were the main ones in Italy in that period. The calculation of Energetic Requirements follows the normative indications Law 10/91, EN 832 and UNI 7374 with a simplified method. th Plea2004 - The 21 Conference on Passive and Low Energy Architecture. Eindhoven, The Netherlands, 19 - 22 September 2004 Page 2 of 2 The approach wants to adopt simple solutions for the study of past typologies. The comparison can be made in orders of magnitude, aiming to direct comparisons and the following search to a specific diagnostic survey of each case. This investigation could be done even in the summer period, and therefore it would estimate the natural cooling of the building. In this paper the energetic study of building typologies is introduced as a useful instrument in order to focalise technological research in the planning and legislative stage. - To create a premise that regulated the thermal gradient between inside and outside, and from the ground to the stairs to first floor. 1. DESCRIPTION OF THE SHACK TYPOLOGY ARCHITECTURE ACTIVITY CLIMATE The shack is a building its architectonic connotations are determined from a mild territorial context. Romagna (latitude 44°33, longitude 12°34) is a region situated in the north centre of Italy facing the Adriatic Sea. The land is mostly flat or with hills. The Appennines chain is located southeast and the area extends to sub hill. The shack is located on the border of Po valley in an area without the urbanization that has grown on the coastal tourist zone. The economy was originally agricultural conducted by landowners. From the XX sec. the agricultural activity was abandoned. The tourist development, recently transformed in other productive fields, has created urbanization of coastal wraps eliminating completely the agricultural origin. The climate is mild, in winter months the temperature varied between -5°, -2°C with a cold wind from the North, in summer months the maximum temperatures is of approximately 21-22°C, coming from tendentially warm dry convent from Sud-Est. Rainfall are between March-May and septemberNovember even if in the last decades their regularity has altered. The climatic parameters of Italian national standard Law 10/91 and UNI 10349) which characterize the area are reported in table I Table I: Climatic parameters in the area Climate zone E Outside temperature -2°C;-5°C Period of heating 183 Days Wind velocity 2.3 m/s (N.O.) 2. BUILDING TYPOLOGY The shack is situated in the centre of the courtyard. The distribution is on two floors: Ground floor: Stable for ovine bovines and shelter tools Premises connected to the agricultural activity: First floor. Living room and kitchen where meals were cooked, a warehouse was located in the south side. The architectonic typology is characterized by the presence of a porch closed to ground. The porch has two functions: - To avoid overheating of the façade. Creating a protected zone of shadow in the summer as well as from the wind in the winter. Figure 1: example shack typology The interchange between the two areas was possible due to a connection stairs. Stairs are another element controlling thermoregulation. It connected the porch with the first floor with the function to avoid in the winter the direct income inside the room with fireplace. During the summer enabled to take advantage of the thermal gradient between the temperature of the porch and the cooling action of the ground compared with the external temperature. The openings towards the outside are all of the same dimensions. The windows are another element that carries out the function of thermoigrometric control of summer and winter. Their dimensions are reduced in order to reduce dispersion during summer overheating. The shutters are made of the bulkheads in full wood (some of them with strips) so they can be opened and be closed. They had the function of protecting from the wind and isolating from the winter infiltrations; whilst in the summer they protected from the solar radiation but permitted an air change. The thermoregulation of the building followed these elements guideline and the distribution of the activities. If a similar building should be planned following the indications of the enforced norm, the satisfaction of comfort requirements would be only possible through the heating building-system. The contemporary constructive design would exclude the elements over described. Moreover, the same th Plea2004 - The 21 Conference on Passive and Low Energy Architecture. Eindhoven, The Netherlands, 19 - 22 September 2004 Page 3 of 3 distribution of the activities would be upset in case of only residential use. Covering wooden structure and wooden flooring with ventilation and tiles, U=4.85 kcal h/m°C, This value for the cover is underestimated, considering the cannucciato (false ceiling with canes of river tied together and plastered) the value of 2.42 kcalh/m°C. could change. Table II: Structure Figure 2: The shack 3. ENERGETIC REQUIREMENTS - COMFORT PARAMETERS The distribution of temperatures related to the activity is described in the historical data of the Handbook of the architect: They are: -Ground floor: 12°C (wine cellar stable shelter tools); -First floor: 14°-16°C (kitchen, warehouse), 16-18°C (other rooms). The value of relative humidity was not indicated. Actually Italian standards require a temperature of 16-18°C for the premises of laboratories, warehouse and stables, and 20°C for other rooms where people stay in winter season, with a relative humidity of the 50-70%. These parameters have been considered during the following. 3.1 Calculation of the thermal dispersions in winter regimen For the purposes of this article the thermal dispersions will be estimated by means of a simplified model, in which the temperature are found in the Donghi Handbook of the Architect, and in the Italian national standards, respectively. From the comparison between the two methods, we will verify the energy variation that has become necessary. This comparison will be useful for: - verifying as the model affects the calculation of the dispersions; - quantifying the values of comfort. - verifying the effect of natural thermoregulation. In the Donghi handbook the windows structure increase of 10-15% the dispersion for ventilation because of the fixture, and the use of a single glass that caused infiltrations and difficultly calculable draughts. 3.2 Thermal characteristics of buildings in XIX cent. The thermo-physical properties of buildings in XIX century could be summarised as: - Vertical structures: Bearing structure in lateritious masonry, bearing thickness 0,50 meters, U=0.91 kcalh/m°C; Windows chassis made of fir with single glass, 2.60<U<5.00 kcalh/m°C; - Horizontal structures: Attic wooden beam + small wooden beams + tiles + background + pavement, U=1.59 kcalh/m°C; bearing structure in tile Window Attic Roof in tile According to the Donghi Value of the Thermal Trasmittance U 2 kcalh/m°C W/m K 0.91 1.058 National standards: enforced U 2.60-5.00 1.59 2.42 (4.85) 4.946 2.099 1.159 4.419 1.489 2.814 (5.640) 2 W/m K 1.235 4. CALCULATION OF THE ENERGETIC REQUIREMENTS 4.1 Calculation of the energetic requirements described in the handbook ante XX sec. For the calculation of the ventilation of the premises the formula indicated from the Handbook of the Architect for the disposal of the air is: A = 0,358 ⋅V ⋅ (ti − t e ) 3 where: V = volume c p = 0,357 [kW/m °C] Ground Floor First Floor th Plea2004 - The 21 Conference on Passive and Low Energy Architecture. Eindhoven, The Netherlands, 19 - 22 September 2004 Page 4 of 4 East Wall 13.80 1.06 14.00 16.00 -29.20 - 11.61 1.06 14.00 18.00 -49.13 13.80 1.06 17.80 1.49 17.80 2.8140 14.00 14.00 14.00 -5.00 12.00 -5.00 Windows 2 windows 2.4 14 -5 Thermal links 15% 277.41 53.01 951.69 1437.16 (Qt) (W) 201.51 201.51 245.80 (Qo) (W) 2066.08 South Wall toward room West wall Floor Ceiling Trasversal Section 4.419 Figure 3: Location of rooms in the building Total dispersion During the winter period the heating is supposed to be on for 183 days, with an external temperature of 2°C. Table II: Surfaces and temperatures in the rooms Ambient 1 Living room 2 Workshops-office 3 Rooms TOTAL TOTAL (with walls) 2 °tint 16°C 14°C 18°C 20°C m 30.54 19.82 59.54 142.80 168.00 Table III Ambient 1-(LIVING ROOM) Ambient Mq H °tinside °toutside V 30.54 3 16°C -5°C 91.62 Living room Ventilation V/hour 111.69 m3 0.5 Opaque plant surfaces North Wall 12.12 East - Wall 13.41 towards room East- Wall 20.01 toward stairs South Wall 8.61 West Wall 16.74 toward room Floor 37.20 Ceiling 37.20 Windows 2 windows Thermal links 2.4 c air 2 (kW/m K) 0.358 U 2 (W/m K) 1.058 1.058 °t in °t out 16 °t in -5 °t out 16.00 16.00 -5.00 18.00 (Qv) (W) 419.84 (Qo) (W) 269.28 -28.38 1.058 16.00 12.00 84.68 1.058 1.058 16.00 16.00 -5.00 18.00 191.30 -35.42 1.489 2.814 16.00 16.00 12.00 -5.00 4.419 16 -5 221.56 2198.30 2816.64 (Qt) (W) 222.72 222.72 455.90 15% Total dispersion Table IV: Ambient 2-(WAREHOUSE) Ambient Mq H °tinside 30.54 3 16°C Warehouse Ventilation V/hour c aria °t in 2 (kW/m K) 53.40 m3 0.5 0.358 14 Opaque surfaces plant U °t in 2 (W/m K) North Wall 11.61 1.06 14.00 (Qo) (W) 3915.11 °toutside V -5°C 91.62 °t out (Qv) (W) -5 °t out -5.00 181.61 (Qo) (W) 233.38 Table V: Ambient 3-(ROOMS) three Rooms Ambient Mq H °tinside °toutside V 47.69 3 16°C -5°C 143.07 Rooms ventilation V/hour c aria °t int °t est (Qv) 2 (W) (kW/m K) 143.07 mc 0.5 0.358 18 -5 589.02 Opache Plant U °t int °t est (Qo) 2 surfaces (W/m K) (W) North wall15.00 1.0580 18.00 -5.00 365.01 North wall 11.64 1.0580 18.00 14.00 49.26 toward warehouse East wall living 13.26 1.0580 18.00 16.00 28.06 room East wall 18.35 1.0580 18.00 -5.00 446.53 South wall 26.64 1.0580 18.00 -5.00 648.26 Wall West- 13.41 1.0580 18.00 16.00 28.38 living room West wall – 20.01 1.0580 18.00 12.00 127.02 stair West wall 13.26 1.0580 18.00 -5.00 322.67 Floor 47.69 1.4890 18.00 12.00 426.06 Ceiling 47.69 2.8140 18.00 -5.00 3086.59 5527.84 Windows (Qt) (W) 2 windows 7.2 4.4190 18 -5 731.79 731.79 Thermal links 15% 938.94 (Qo) (W) total dispersion 7787.59 Therefore the total dispersion calculated with the Donghi Handbook becomes: 13768.77 W. Considering winter season, which lasts 182 days, the total dispersion becomes 13.76 x 8 x 183 = 20144.64 kWh = 20.14 Mwh/year 4.2 Calculate Dispersion with Law 10/91 Following the Italian standard (Law 10/91), and considering the room with the dimensions: 10.20 x 3 14.00 x 3.00 m , the dispersions are: Table VI : Dispersions 2 Ambient m 30.54 Total Ventilation V/hour 428.40 m3 0.5 Opaque surface North wall plant 42.00 with Italian standards h °t inside °t outside 3 16°C -5°C c air °t in °t out 2 (kW/m K) 0.35 20 -5 U °t in 2 (W/m K) 1.235 20.00 V 91.62 (Qv) (W) 1874.25 °t out (Qo) (W) -5.00 1296.75 th Plea2004 - The 21 Conference on Passive and Low Energy Architecture. Eindhoven, The Netherlands, 19 - 22 September 2004 Page 5 of 5 East wall South wall West wall Floor Soffitto Windows 7 Windows Thermal Brings 30.60 42.00 30.60 142.80 142.80 8.4 1.235 1.235 1.235 2.099 1.159 4.946 20.00 20.00 20.00 20.00 20.00 20 -5.00 -5.00 -5.00 12.00 -5.00 -5 15% total dispersion 944.78 1296.75 944.78 2397.90 4137.63 11018.58 (Qt) (W) 1038.66 1038.66 1808.59 (Qo) (W) 15740.07 The total amount of dispersion calculated with Italian standard (10/91) is 15.74 kW. Therefore approximately 2 kW must be supplied in addition to satisfy modern comfort requirements. Table VII: Different behaviour of the fuels combustible XIX°cen XX cen Gap Consumption MWh/jear firewood η 15% 20.14 23.04 2.90 Kg-wood 31026.93 35494.56 4467.63 MJ/jear camino η 15% 483360.00 552960.00 69600.00 TEP Pellet stove η 80% 11.60 13.27 1.67 MJ/jear 90630.00 103680.00 13050.00 kg-wood 5817.55 6655.23 837.68 TEP 2.18 2.49 0.31 80560.00 92160.00 11600.00 mc/year 2337.10 2673.63 336.52 TEP 1.93 2.21 0.28 85298.82 97581.18 12282.35 kg/year 1865.68 2134.32 268.64 TEP 2.05 2.34 0.29 gas methane η 90% The building had rooms with different temperatures which could create airflows and discomfort. However, in winter season aeration is less utilised. Calculating the heating on for 8 hours a day for 183 days a year, in XIX century there was dispersion of: 13.76 x 8 x 183 = 20,14 MWh/year, whilst in XX century 15.74 x 8 x 183 = 23,04 MWh/jear. Therefore the difference is 2.89 MWh/year. Considering the effects of solar radiation in winter that was surely considered from the occupants, the difference (energetic gap) would be even greater. 25,00 20,15635 η 90% MJ/year 0.00 LPG η 85% 0.00 η 85% MJ/year 23,04336 TEP 14,00 20,00 13,27 12,00 15,00 XIX 11,60 XX-FIREPLACE XX-STOVE 10,00 10,00 XX-METHANE 5,00 XX-GPL 8,00 0,00 6,00 -5,00 XIX° (MWh) XX° (MWh) -2,89 4,00 2,49 Difference (MWh) 2,00 2,21 2,34 Figure 4: Differences between XIX and XX century 0,00 5. COMPARISON XIX XX-FIREPLACE XX-STOVE XX-METHANE Calculating energetic dispersions following Donghi standard and comparing the results with the actual Italian standards, there is an increase of dispersion of 1.98 kW that is 2,9 MWh. This is caused only by the different gradient of temperature between which are nowadays requested after the introduction of new system technologies. This difference involves greater energetic expenditure, depending on the kind of fuel that is utilised and the relative TEP. Consequently a greater emission of CO2 is possible. Infact 1MJx 2,4 10-5=1 2 TEP of consumptions (used technology and Calculate TEP) depending on the fuel. XX-GPL Figure 5: Comparison between different fuels CONCLUSIONS This study wants to highlight the role of architectonic typology and the constructive tradition in defining energetic behavior. The typology is not the only cultural factor that takes part in defining the energetic consumption; the other important one is the cultural habit of the place. To supply technological possibilities and standards of comfort climate to us in way undiversified to the historical habits involves an energy increase. Even a better responsibility in th Plea2004 - The 21 Conference on Passive and Low Energy Architecture. Eindhoven, The Netherlands, 19 - 22 September 2004 Page 6 of 6 environmental issues, as well as a more sensitivity about clothing, could contribute to energy saving. REFERENCES [1] L. Gambi “La casa rurale nella Romagna” (“The rural house in Romagna”, historical study on the architectonic typology of the shack inhabitant of Romagna), Centro Studi per la Geografia Etnologica, Firenze, 1950 [2] D. Donghi “Manuale dell’architetti VOL.I” ("Handbook of the architect" VOL I) UTET Torino, 1933 (It reassumes the architectonic and hygienic constructive acquaintances in Italy in XIX the century) [3] P. Menna “L’energia Pulita” ("the Cleaned up energy"), Il Mulino, Bologna, 2003 [4] Law 10/91, EN 832, UNI standards references.