page 1
I N N O V A T I V E PA S S I V E C O O L I N G
h tt p :// w w w . s u p e r s u st a in a b l e . o r g
Le Cor busier co m pa r ed the fu nctioning of buildings to the m achine. Why do not consider the cl adding of the building as a (w ell supplied with blood) skin. All the m a m als use a syste m of blood v essels to keep a ppropriate te m per atur e of their bodies. M aybe w e ca n m eta bolize our buildings in the way a nim als do it. So...let’s im agine a building with a structur e full of sm all por es-pipes at the outer surface, r egul ating te mper atur e inside. Each hole will be a pa rt of a coher ent syste m of con nected pipes. By putting a nd densifying pipes on the proper side w e ca n build a v ery effectiv e syste m.
page 2
I N N O V A T I V E PA S S I V E C O O L I N G
h tt p :// w w w . s u p e r s u st a in a b l e . o r g
Is it only a bio mimic, futuristic dr ea m? Not a ny m or e. The r esea rchers, using physical l aws, prov ed th at this is co m pletely possible. To u ndersta nd HOW w e h av e to m ov e 200 yea rs in the past. In 1822 Fourier (the first who forcasted gr een house effect), pr esented his wor k on heat flow, know n now as the l aw of Heat Conduction. Fro m his wor ks w e know th at if two bodies with differ ent te m per atur es inter act on each others, they try to equal their te m per atur es.
Co m m e nt to th e d r awin gs: Th e co nd uctio n is bet w ee n to b ody touchin g e ach oth er o r insid e a m ateria l. W h e n it is with a dista n c e w e spe a k a b out co n v ectio n a nd r a diatio n. Th e Fou rier’s l aw co n c er n o n ly co nd uctio n.
Conclusion: Ev en fro m a certain dista nce w e ca n ch a nge the te m per atur e of one obj ect by using a nother obj ect by r adiation. In this way w e ca n cool dow n or heat up (depending on needs).
page 3
I N N O V A T I V E PA S S I V E C O O L I N G
h tt p :// w w w . s u p e r s u st a in a b l e . o r g
Th at is why by the r adiation of the sta rs w e ca n achiev e ch a nging the te m per atur es of m aterials on Ea rth, ev en if ther e is a dista nce betw een the m. W e ca n achiev e differ ent te m per atur es on differ ent m aterials depending on exposur e of the surface on the sta rs (f.g. su n) a nd ch a r acteristics of the m aterial itself. Ther e a r e two ch a r acteristics of ev ery each m aterial: - a bsortivity (alfa)(how m uch energy is collected/focused by a m aterial) - e missivity (epsilon)(how m uch energy is r eflected/ sh a r ed with the sur rou nding by a m aterial) W e ca n divide m aterials on hot ones (big a bsortivity, low e missivity) like pl atiniu m, or cold ones-like a nod alu miniu m (copru m). Ther e a r e alr eady ex a m ples of using r adiation betw een the m aterials to bal a nce the te m per atur es of the buildings(industrial buildings).
Salm a a n Cr aig, the r esea rcher fro m Bru nel U niv ersity in UK,studied m a ny ex a m ples a nd sh a pes, which will help to r egul ate the te m per atur e.
page 4
I N N O V A T I V E PA S S I V E C O O L I N G
h tt p :// w w w . s u p e r s u st a in a b l e . o r g
He co m e to the conclusion th at if he m a ke a n atriu m in this sh a pe(cone sh a pe-dr awing), air, which is going dow n through the roof, will cool dow n the atriu m, befor e it r each the end of the sloping roof. How ev er, the roof m ust be m ade of a cool a nt-the m aterial r ealtiv ely cold (co m pering to the sur rou nding air), due to the su n/sta rs r adiation.
Following the ex a m ple a bov e, Sal m a a n Cr aig, in his desig n, choosed a cone as the m ost effectiv e sh a pe. How ev er to cool dow n the building, the m ost effectiv e will be not a big cone but few sm all onces, situated a rou nd, in the skin of the building, a nd con nected to each other into a coher ent syste m. In the pl aces when you need the m m or e you will find the m m or e
The syste m of pipes will wor k a bit like blood v essels in the eleph a nt’s ea r:cu m ul ated v ery close to skin wher e it is the m ost efficient to cool dow n. A nd l ack of the m at the pa rts wher e supposed to be wa r m(the skin of the ea rs is thin a nd ea rs ca n m ov e a nd v entil ate easily). Sal m a a n Cr aig called this syste m BioTRIZ.
page 5
I N N O V A T I V E PA S S I V E C O O L I N G
h tt p :// w w w . s u p e r s u st a in a b l e . o r g
This technological solution was tested on J ea n Nou v el’s proj ect:Lou v r e A bu Dh a bi. It is estim ated th at the therm al m ass in the bio mim etic roof would r e m ain on av erage 4.5°C cooler th a n in a sta nda rd roof ov er a yea r in Riyadh, Saudi A r a bia.
To su m up: BioTRIZ is the syste m of pipes, cooling dow n the building, situated inside the cl adding of the builing, close to its exter nal surface, position ned in the pl aces wher e is the m ost efficient (r ega rding en viron m ent condition of the location).
M or e a bout the proj ect: http://www.libsea rch.co m/view/15830 http://www.in v entiv e-desig n.net/co m ponent/option,co m _ jo m bib/task,show bib/id,713/ http://www.sciencedir ect.co m/science/a rticle/pii/ S1672652908600074 Bru nel U niv ersity A rchiv es http://bur a.bru nel.ac.uk/h a ndle/2438/3315 BioTRIZ for the J ea n Nou v el proj ect Lou v r e A bu Dh a bi http://www.fa bricate2011.org/128/