Esercitazione 5_ Surfaces' Analysis (Solar Radiation)_Eleonora Velluto, Sibilla Ferroni

What we have done is a solar analysis, that is about the envelop: the exposition, the shadow analysis, the solar radiation.

• We have set the building with the angle directed to the North

 -- The resultant exposition of the facades is North-East/ North-West/ South-East/ South-West

• To shade the surfeces mostly exposed to the sun radiation we have adopted different strategies

 -- Caducous trees, projections, working on the envelop

• To control the solar radiation we have reflected on alternating transparent and opaque surfaces

 -- Transparent surfaces are allowed where can come sun rays in winter and where we can guarantee appropiate shadow in summer season; opaque ones are positioned where we need to reduce the heat transfert

To understand how the solar radiation works releted to the exposition, we have analyze the solar radiation of the volums, using the Vasari Beta3 software:

Winter, morning – 21/12 h.9 (EAST)

Winter, afternoon – 21/12 h.14 (WEST)

Summer, morning – 21/06 h.10 (EAST)

Summer, afternoon – 21/06 h.16 (WEST)

From these pictures we have pointed out the things we have to work on.

1. The transparent surfaces (which we need in the mesure we have set the project) can be mostly positioned on the South-West/South-East exposition, less on the others.

First project of windows

Winter sunrise – 21/12 h.7,37 (EAST) . The North-East windows don’t have any light, since the sun rise up.

Winter morning – 21/12 h.8,37 (EAST). The South-East surfaces have sun light from early in the morning.

Winter, first afternoon – 21/12 h.13,37 (EAST) . South-East surfaces have light till the first afternoon.

Winter, first afternoon – 21/12 h.13,37 (WEST).  South-West windows have sun in the afternoon.

Winter, sunset-21/12 h.15,37  (WEST). South-West windows have shadow at the sunset

 2. We need to protect the transparent surfaces from the summer solar radiation by vertical protections, the caducous trees are a good solution

Summer, morning – 21/06 h.10 (SOUTH). South-East windows need orizontal protection from the sun light.

Summer, noon – 21/06 h.12 (SOUTH). Even the South West surfaces need an orizontal projection.

Summer, afternoon – 21/06 h.14 (SOUTH). The vertical protection caused by trees is not sufficent, must be higher.

Summer, afternoon- 21/06 h.16 (SOUTH). Trees work good as protection from 16h till sunset.

Summer, afternoon – 15/08 h.16 (SOUTH-WEST). Trees are working as vertical protection.

Summer, all the day – 21/06 sunrise-sunset (EAST).

Summer, afternoon – 21/06 h.16 (WEST)

We could have a better protection thanks to higher trees, or we have to project a vertical protection working on the envelop of the buildings.

Another things to take care on, is that for the first years of our building trees can't protect the surfaces because they need time to grow up. How can we solve this problem? Temporary panels applied on the envelop could be an answer?

 3. In summer, where we can’t have trees we can protect the transparent surfaces by projection, which are working good as protections in the morning as late in the afternoon

Summer,morning – 21/06 h.8,33 (SOUTH-WEST). Projections protect the surfaces from early in the morning.

Summer, noon – 21/06 h.12,33 (SOUTH-WEST). Projections work even at midday

Summer,afternoon -21/06 h.16,33 (SOUTH-WEST). The horizontal protection, for west-exposed surfaces, is not sufficent to protect them in the first hours of the afternoon

Summer,late afternoon – 21/06 (SOUTH-WEST). Projections work late in the afternoon, till sunset.

Summer,midday – 21/06 h.13,33. Projections working at the hottest hours.

Summer,morning – 21/06 h.11,33. Projections in the morning, after the first hours of the day they are working good all the time.

Then we went deep in the study of the solar radiation for the transparent surfaces.

We create a new “Style” (see the image below) from the "Solar Radiation" window

At the end of this process, it’s possible to choose in what time of the year we want to make the analysis.

We choose the “Multy-Day Solar Study” to have the data about the peak and the comulative value of the solar radiation on our transparent surfaces.

The problem that occurs when you choose a long period (as we’ve made: 01/06 – 21/09, h.9 - 19), is about the dimention of the numbers’ font (as you can see below), which is too big and doesn’t allow you to read anything. So you have to regulate the “Scale”, using the “Properties” window.

Summer Period: 01/06 – 21/09 (9h-19h) . The cumulative value of the solar radiation is: 201 kWh/sqm.

Winter Period: 21/09 – 19/03 (10h-16h). The cumulative value is: 78 kWh/sqm.