Abstract:
One of the characteristics of to.lloffice building:; in nhah city i< the extensive uoe of
glazing on d,e bwlding facades. This inct~a,ing U3e of glaS3 has cau3ed con:;iderable
changes in the relation3hip b~tv.'een interior and ambient dimate, where the problem of
overheating ha3 become a major concern. So facades of tall building< need protection
from soJar heat gam to achieve desitable indoor env;ron.meot and to reduce the enetgy
consumption ill the building" by the air conditioning "ystem. External shading devices
c.~n be utili,ed to block the ,olar rac.ltltion before it teaches the window surface and
hence more effective than intetrull shading deviccs.
The ptoblem was approached by performance evaluation of sclccted commonly used
shadIng devices of tall office buildings through simulation study_ Shadow simulation
alIo", stud)' of the effect of changes in one aspect, keeping other factots con,tant. The
observations of simulated performancc that occurs due to changing parametcrs allow the
identifiotion of elements, the reduction or introduction of which in the design
contnbute to solar heat gain. Through simulation study, it is possible 10 analyse the
performance of shading devic~' for any period of the yeat. The simulation .luille. were
conducted fot the months from March to September repcc.enring hot-dry and warmhumid
period, which is mo,t .ignificant in term. of dimatic severity. Th~ .imuffition
studics were performed tu evaluate perfonnances of .hading devices and identifY thc
effects of different par-Mneter3 and correffition among parametet' in tcrm. of reducing
soIM heat gain. 1Oi•• tudy also helped to understand the influence of window orientation
on the performance of shading dcvices,
Aftet all the imTstig.J.tions and critical ",-aluanons, a parametric srudy to explore the
strategies fot optimL1m shading wa3 pursued through a series of .,imulations a, solar
geomet'}. is a I'teructable phe<lomenon and much of its impact is quantifiable. Parametric
3rudy allow, "tud)' of various a1t~rnatives ",~th reference to perfoonance of the model
and identifying thc best one. Rased on the parametric study, desj~ reconuncndauons
and de,i~ gmdelines W~rt,derived.
The findings of thl3 thesis ar~ concerned with the problem of soht heat gain jn tall office
buildings in tropical climate hke Dhaka eity. 'Ine rc,uh, of the simulation 3rudies and
patametnc srudic" ha,e been expr~,«ed in tern" of " number of climate re3poll.i,-c
shading d~,ign guidelines. It is expected that th~ application of these gwdelincs ",ill
reduce solar h,'at gain in comparison to that of pres en, ptactices.
