Another style of house in Yazd has internal court yards. The house faces the inner courtyard for lighting and ventilating.
In this kind of house, interesting cooling and heating techniques are used. I just introduce one of these houses that is now used as the School of Art and Architecture of Yazd University (it used to be Mr Rassolian's house and was dedicated to Yazd University). There are some rooms round the courtyard. The courtyard is directed towards the south-west with two parts, a winter part and a summer part.
The main court yard and the Orosi that catch the sun light in winter, (winter portion).
In this part a big room with a large window (Orosi) toward the sun catches the rays of sun, and gets warm very fast in the morning. It gets warm with direct sun. The floor, the walls and the roof are made with mud-brick, and are 1-1.5m thick. They work as good heat storage, so they gain a large amount of heat and they give it back with 7-9 hours delay (time-lag) during night. So the nights are not too cold. The walls that got cold during the night are not effective because direct sun warms the room up during the day. At night to reduce energy use they help avoid heating part of the room, In fact, they do not warm all the room they just make a smaller space for sitting, and sleeping using a small desk (Korsi) with a dish under it filling with red-hot charcoal. The desk is covered with blankets and there is enough space for all the family to sit round the desk and sleep at night. It is a warm, friendly circle to have discussion and improve relationships. I think it could be a very good introduction to this kind of thinking to reducing energy using smaller spaces. This can be easy with the right design of space and appropriate behaviour.
This part works in the summer, gaining the least sunshine, with a wind catcher and a Kollah Farangi (a space with dome roof and vents on the dome) also a Talar.
The summer portion (Talar, wind catcher and kollah Farangi). And the summer room in the corner without any heat gain from sun.
The Talar is a three sided wall space directed to the north-east, it reserves cool in its walls, roof, and floor during the night, and gives it back during the day. Not receiving any direct sun, it does not gain very much heat during the day. Its roof has two layers of mud-brick with an air space to insulate the roof. The wind catcher and the Kollah Farangi are both located in a room that is situated in the corner of the courtyard where there is no heat gain from the sun. The wind catcher catches the cool breezes and leads them into the room, and Kollah Farangi sucks the hot air out of the room. The function is the same as described above for Dowlatabad building.
Sardab
Sardab (literally cool water) is an underground place, where the water of Qanat passes. It is about 6 meters below the floor level. Flowing with cold water. It has very cold and wet air compared to the ambient air. To use this cool and fresh air, there is a duct coming down from the wind catcher leading breezes right to this space. Another duct then leads this cool air to a big underground hall, that is naturally cooler than ground floor spaces, and provides fresh air for this room. Passing this room the cool air will flow to central courtyard and freshen its air.
Underground tunnel under the main court yard.
There are underground tunnels in four sides of the court yard, that prevent damp of flower beds, and pool spoiling the main structure, which is built with mud-brick, and be damaged by wet. These tunnels give humidity to the air and the air will pass out through vents. This is another aid to cooling the system.
