Sun-on-ground

The "sun-on-ground” module of the programme SENCE calculates the shape of the building shadow in a chosen moment. With a sequence of calculated shadows we can exactly see how the shadow "travels” over the building site. In the paper we calculated minimum recommended duration of building shadows at four reference days. The required duration of solar radiation upon the living room window is: 1 hour at December 21, 3 hours at March 21 and 5 hours at June 21. In the research the time around noon was taken into account. The shadows-on-ground were calculated for each hour during the required number of hours at the reference days (11.30-12.30 at 21st Dec., 10.30-13.30 at 21st Mar. and 9.30-14.30 at 21st Jun.). Then the shadows were overlaid. A pattern of shadowing during the selected time was obtained (Fig 4).

Figure 2: Floor plan area of solar volume designed for a pote. Leftacording to foe solar right. s regulation 1-3-5 hours duration, right: the 2-4-6 hours duration. North is on the top of side.

Iso-shadow

The "Iso-shadow" module of the programme "SENCE" (Fig. 5) calculates the duration of the solar radiation on horizontal surface. It is quantified as thermal flow received on a site.

Figure 3: Floor plan area of solar volume designed for a pole. Left:the 3-5-7 hours duration, right: the 4­6-8 hours duration. North is on the top of side.

Iso-shadows are the ratio of the received solar irradiation on a given site to unobstructed solar irradiation received on the same site, expressed as a percentage. ‘ of iso-shadow chart. The chart consists of iso-shadow contours, marking the areas, which receive the same percentage of solar radiation. The quantity of incident radiation is divided into 10% steps, from 0% to 100%, during the optionally selected period of time: day, month or year. In this way it is possible to determine the exact extent and duration of solar radiation on the basis of which the evaluation of the chosen site layout can be made.

In our case the 80% yearly iso-line on a given site was chosen as the minimum satisfactory value. The area arround the 80% iso-shadow line comprises the long morning and evening shadows with low incidence angles. This area has high fraction of received solar irradiation and can be used for neighbouring buildings.