Airbase publication

The rapid growth in residential air conditioning (cooling) in many parts of the world is resulting in increased energy consumption, significantly affecting central electricity systems, and having adverse environmental consequences. Alternatives to conventional electrically powered vapour compression air conditioning are emerging. Building performance simulation can be used to assess their feasibility and guide their development, but only if it can accurately characterize the magnitude and temporal variation of cooling loads, including the impact of architectural and site variables (e.g.

In a metropolis such as Seoul, which has a large population in a dense, built-up area, district heating/cooling systems are popular in terms of energy efficiency and carbon reduction. In order to optimise the generation and distribution of energy in district heating/cooling systems, it is crucial to predict accurate energy demand profiles. In the case of a residential complex, identifying hourly demand profiles is a challenge for the energy managers since there can be a variety of buildings, which are affected by a number of variables: location, orientation and configuration.

The study is placed within the context of local building regulations in India. Building regulations, for fenestration in general and window openings in particular, are, to a large extent, ambiguous in nature. In the context of India, observations show that the regulations specify window size for the sole purpose of ventilation whereas windows are major roleplayers in the thermal and daylighting performance of buildings.

The ability to simulate the effect of trees on natural light performance in buildings is contingent upon accurate simulation of light passing through the canopy. Accurate simulations require some assumption of leaf angle distribution to compute canopy gap fractions. The ellipsoidal leaf angle distribution can very closely approximate real plant canopies. The method requires calculation of leaf area density from observed distribution of gap fraction as a function of zenith angle. Hemispherical image acquisition and analysis is used to measure gap fractions.

This paper investigates the impact of well geometry and surface reflectance on vertical daylight levels in atria with square forms under a CIE standard overcast sky. By reviewing some previous investigations and comparing with scale model measurements the vertical daylight factor calculated using Radiance are validated. More simulated vertical daylight factors for a very wide range of atrium geometries and reflectances are given. From the results the attenuation and distribution of the vertical daylight levels on the wall of a square atrium with different reflectances are displayed.

This paper demonstrates the use of High Dynamic Range (HDR) fisheye images of the sky dome in lighting simulations. The objective is to improve the accuracy of simulations with site specific sky conditions. The luminance information stored at a pixel level in an HDR photograph is used to light the simulated environment through an Image Based Rendering (IBR) technique.

This paper reports the simulation approach and prediction of annual energy performance of PV ventilated glazing systems with daylight saving as applying to typical office environment. Our computer model was developed via the ESP-r simulation platform in association with the RADIANCE lighting software. The new attempt of using indirect interaction between the two simulation programs through daylight coefficient, together with the coupled air-flow network and energy balance technique, has been proved very useful in tackling this kind of long period analysis.

In recent years, highly glazed atriums are favorable to architectural aesthetics and to taking advantage of daylighting and solar heating. However, t he estimation of the building load of an atrium building is difficult because of the complex thermal phenomena occurred in the atrium space. The study aims to find out the methods of conducting accurate simulations of the cooling loads of various types of atriums, using whole building energy simulation tool – EnergyPlus. Cases of atrium buildings are collected and classified into various categories.

Computational fluid dynamics (CFD) can provide detailed information of flow motion, temperature distributions and species dispersion in buildings. However, it may take hours or days, even weeks to simulate airflow in a building by using CFD on a single central processing unit (CPU) computer. Parallel computing on a multi-CPU supercomputer or computer cluster can reduce the computing time, but the cost for such high performance computing is prohibitive for many designers. Our paper introduces high performance parallel computing of the airflow simulations on a graphics processing unit (GPU).

Advanced natural ventilation (ANV), often characterised by the use of dedicated ventilation stacks, shafts and other architecture features such as atria, light wells, has gained popularity for natural ventilation design in recent decades. In this research, a prototype ANV system is proposed, and the likely thermal performance in a range of UK climatic conditions predicted using dynamic thermal simulation.