Es 5_ NEW 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, afternoon 21/12 h.15,37  (WEST). South-West windows have shadow from the highest building.

We tried to solve the problem re-modeling that building, changing the position and the dimentions.

Changed conformation: the building is moved through the left side and now it's only 3 floors high. No more shadow in winter afternoon.

But now.. what happens during the morning? 

The other buildings influence the new one so we have to make other changes.

Moving again the building we have found the final conformation. There is enough light during winter morning.

 

 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?

Now: what happens in winter?

Situation during the morning. Trees doesn't make shadow on the surfaces. Shadows are only determined by the exposure of buildings.

Midday situation in winter. Trees have no leaves, the shadow they make is not enough to stop solar radiation.

 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.

Now.. What about the new conformation (see modified maked to solve winter problems)?

We have the new building where we have worked to reduce the influence of buildings around. That's good during winter.. but in summer we have a South exposed surface.

Trees are not a good solution. As we have seen before they work good as vertical protection: from solar radiation during morning (for East exposed surfaces) and afternoon (for West exposed surfaces). 

Trees don't make any shadowing during midday (and so the hottes hours of summer days).

We tried different dimention, but according with our project we have choosen a 1.2 m protection,which is enough.

But we had had to control this protections during winter time: will they make shadow?

During morning we don't have problems.

Neither during midday: Winter sun make a shorter but even lower trip in the sky.

As you can observe in the upper image, we have a problem with the influence of the other two buildings on the right side. While we where making this analysis we noticed that and we tried to find solution. (see below)

We needed to reduce the higher of the building you see in the front.

Because we were working with staggered floors we brought the higher of building to 7,5 m.

Winter afternoon situation. There is still influence, but less than before.

The lower floor windows in the image belong to the common room which is a unic big room, so the ammount of radiation and lighht required during winter is brought by the south exposition. (see below)

For the common area it would be possible to open a window (as you can see here) to keep su light. The only critic point left is the one we've marked in the image,

which is the window of  a private room, at the lowest floor.

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.

 

HOME SURFACES ANALYSIS_ Eleonora Velluto's house

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The exposure of southwest is indeed problematic. We didn’t have the opportunity to change it because we have to follow the grid imposed by our Master plan.
I brought as a case study my own home. Its exposure is very poor, in fact, it only faces southwest and there isn’t any projection that covers from the direct sun. The house overlooks the terrace, where all the sun is catalyzed and contributes to a further heating of the interior.

WINTER

SUMMER

During wintertime this could be better, but is summer time we can’t but turn on the air conditioner. The only part of the house were the climate is livable is the living room. Trough a winter garden opened at northeast, the air can circulate and create pleasant ventilation.

The perfect climate of the house is the guesthouse, which is covered at southwest by a gazebo and has.
Now we can apply this case to our project.  On the left side, buildings have medium-small openings at northeast and big openings at southwest that should be covered by some projection (ex. The partition walls and the floors can go forward from the cladding).
On the right side, the stairs of the duplex that are external from the structure gives the shielding from the southwest sun, whereas the northeast side will have medium-small openings.