The role of multiple courtyards in the promotion of convective cooling

Ernest, Raha (2011) The role of multiple courtyards in the promotion of convective cooling. PhD thesis, University of Nottingham.

[img]
Preview
PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
Download (92MB) | Preview

Abstract

This study is set out to confirm the phenomenon commented on by Hassan Fathy (1986) that the temperature difference between courtyards has a role in the promotion of convective cooling through transitional spaces in a multiple-courtyards building in semi and regions. The transitional spaces situated between courtyards are identified with specific titles such as Takhtabüsh in the Egypt; and Tablinum in a Roman Domus. However, despite the historic significance of these spaces, most studies have mainly focused on the climatic performance of buildings with a single courtyard. Empirical and numerical study has not been conducted on the nature of this phenomenon. In order to confirm this conjecture, this thesis is set out to conduct fieldwork and theoretical investigation.

This thesis is a single case study of the Casa de Pilatos in Seville, Spain. The case study is used to develop a methodology for analysis of multiple-courtyard phenomenon. Field measurement and mathematical models are used to determine the drivers for yard-to-yard airflows. The fieldwork uses data logging equipment to record dry bulb temperatures, relative humidity, and air velocity through the transitional spaces. The amount of cooling attributed to yard-to-yard flows and implication to cooling requirements in a contemporary environment are evaluated. Adaptive criteria of Nicol and Humphrey (2001)'and Brager and de Dear (2001) are used to predict the thermal comfort of subjects.

The drivers are determined through analysis of buoyancy `stack' forces and local wind regime. The building mass introduces three hours delay with up to 2.5kW or 36W/m2 variation in heat balance in the transitional spaces by 15: 00h. The calculated volume flow rates through the transitional space are 5.3m3/s (equivalent to 5kW or 71 W/m2 in convective cooling) at 15: 00h. The DBT in the gardens are up to 11 k below the WBT. It is shown that multiple-courtyards phenomenon is a robust strategy accommodating a large variation in temperatures. The study confirms that temperature difference is the driver for convective flows through transitional spaces.

This study presents an opportunity to investigate the applicability of this concept in the contemporary context. Findings of this study have direct application in the reduction of cooling energy in widely used courtyard concept in semi and regions.

Item Type: Thesis (University of Nottingham only) (PhD)
Supervisors: Etheridge, D.
Ford, B.H.
Keywords: Casa de Pilatos, Air conditioning, Buildings in semi-arid regions, Convective cooling
Subjects: T Technology > TH Building construction > TH7005 Heating and ventilation. Air conditioning
N Fine Arts > NA Architecture
Faculties/Schools: UK Campuses > Faculty of Engineering > Built Environment
Item ID: 12990
Depositing User: EP, Services
Date Deposited: 19 Dec 2012 11:29
Last Modified: 22 Sep 2016 18:51
URI: http://eprints.nottingham.ac.uk/id/eprint/12990

Actions (Archive Staff Only)

Edit View Edit View