Master works

Msc Environmental Design of Buildings 

•  Module: Environmental Design Application 

• Assignment: summer improvement of a typical house in Athens 

Problem. Typically buildings in Greece are made of concrete. During summer, constructions suffer from overheating due to the high solar intensity [Fig. 1] as a result, the dwellers use excessively air-conditions to eliminate the high internal temperatures that occur. Consequently elevated are not only the electrical loads but also the outside temperatures owing to the system’s heat

emission.

Aim. With purpose to restrict heat transfer from the building envelope and consequently the air-condition usage, a study made in order to apply in a typical house a feasible solution regarding passive cooling. A four-storey house selected in the city center of Athens to serve this research.

Law. All buildings are built in compliance with many laws regarding their spatial arrangement [Fig. 2] so a further on site building transformation was hindered.

Solution. However, all buildings in Greece including the one selected have overhangs so the effectiveness of a second external blind-wall layer attached at the ending of the overhang is here examined [Fig. 3].

 
Considerations. The length of the shade  the surroundings cast to the building, calculated using solar geometry. Through this was indicated that the building’s southern facade and roof were mostly exposed consequently, those two are the surfaces having the additional double wall layer. The seasonal sun path diagram was studied to define the blinds slope to achieve solar access in winter and diffuse lighting in summer. The blinds width and distance height were studied too. [Fig. 4, 5].

Application. The lightweight material was placed in a narrow distance from both southern side and  roof surface, it was expected the sun to heat up quickly the secondary metal surfaces. Indeed the air passing through the gap between the two walls, had lower temperature than the lightweight fabric and took the lightweight material’s heat away, before it could be transferred to the concrete building envelope. Target of this method was to remove the solar gains collected by the shader and keep the temperature of the cavity low. In this way heat was removed from the system not so much by shading as by ventilation. 

Calculations. Two models designed in ECOTECT one with and the other without shader and then exported in HTB2 [Fig. 6, 7] to record surface temperatures for a day in June, July and August. Heat transfer equations computed in excel to observe the effect in both buildings. For the building without shader, the heat transfer equations include heat gain by direct radiation, plus the one received from its surroundings and by conduction, while heat losses by convection. The same applied to the shaded building, noticing that it received only the radiation emitted by the shader [Fig 8].

Results. The graph [Fig. 9] illustrates results for the day in June and indicates that the building with the shader has lower heat transfer to the one without. In total for the whole summer period examined there was found that the heat flow rate was reduced for 33%.

•  Module: Environmental Design Practice

• Assignment: Aloe Vera Factory production 

 
 location. In the foothills of Himalaya located in the northern part of India there is a place called Rishikeshi. Aim of this project was to enable a building with a certain activity in to the particular climate of that place.

seasons. Winter - cold, spring -temperate, monsoon - hot & humid, summer - hot, autumn -cool. 

Needs in an Aloe Vera Factory production

washing area. High is the activity this space holds concerning the plant washing procedure so the space requires ventilation.

juice collecting area. In this area the activity is considered as sedentary were people would be seated to obtain the juice from aloe leaves.

boiling area. Due to the certain usage of this area smoke and steam is produced from the aloe juice boiling procedure leading to increase the interior temperature. A chimney is required to remove the smoke but a part of it might stay in the room for these reasons are required cooling ventilation and natural lighting.

packing area. This activity again is considered as sedentary here, the demands for heating cooling and lighting should be considered.

storing area. A place that requires shading and to remain cool.

Site and Wind analysis. A piece of land was selected in the area of Rishikesh  to serve this research. Then a model of it designed in ECOTECT and exported in winair to test the most prevailing winds of the site for several directions. Figure [1] alonside depicts the export from winair for the South West wind [5.5m/s].








In the image on the left [Fig2] are highlighted  the areas in the site that create  a shelter and those that are exposed  as found using winair. This research aided to reveal a preferable position for the building placement. Since, cooling requirements are  higher than heating ones, the natural elements of the site will be employed in order to provide additional shelter from the sun.

After concerning the building demands, wind and site analysis the most favorable site position was found, marked in black on [Fig 2]... Because. Trees will offer shade in summer and a wind barrier along with sun penetration in winter.

Through area micro-climate literature review, the sandy soil close to the river, was found having high albedo. This type of soil minimizes the solar reflectance, plus to the fact that the river itself provides a kind of coolness.

Climate analysis that conducted through ECOTECT indicated the face of the building due to south. The sides due to east end west are narrow to avoid further solar exposure which is difficult to be controlled.

 

synthesis. The arrangement of the building zones is shown in Figure 3.  It was decided to dedicate one room to each production stage since they hold different requirements.

passive cooling. The building areas spatial position formed in order to shade each high activity room; this was achieved by jutting in and out the five areas around a notional axis [Fig 4]. The jutting in  areas were those having lower activity and placed at higher level from the remaining jutting out areas that have higher activity level in order to be shaded and protected from summer sun.

Still the elevated areas were bombarded with sun in summer so it was decided to place shaded ponds in each one of these roofs. As the “pond rooms”, are placed higher, then natural ventilation is easily induced. This, in combination with the building arrangement that creates wind wigs,  helps the evaporation process created by the air passing through. Through a study made using psychometric charts and mathematical equations the ponds temperature is illustrated in figure [6] .

Please note that only a part of the cooling study is here provided.