Application of externally-coupled BES-CFD in HAM engineering of the indoor environment

The high importance of indoor environment performance aspects such as surface condensation, mold growth, thermal comfort, etc., is widely recognized. High-resolution simulation of heat, air and moisture (HAM) transfer can be used to enhance the prediction and analysis of these aspects. For this purpose, a coupling mechanism has been developed in order to perform run-time external coupling between Building Energy simulation (BES) and Computational Fluid Dynamics (CFD). This paper presents the results of indoor humidity calculation using the new coupled tool for the BESTEST case- 600.

External coupling between BES and HAM programs for whole-building simulation

This paper discusses a procedure for the two-way run time external coupling between Building Energy Simulation (BES) and building envelope Heat, Air and Moisture (HAM) programs for enhanced whole building simulation. The coupling procedure presented here involves a description of the relevant physical phenomena at the interface between the programs, domain overlaps, coupling variables, coupling strategy and types of boundary condition. The procedure is applied using the programs ESP-r and HAMFEM, where the implementation and verification issues are discussed.

The effectiveness of introducing effective energy savings measures for households in Japan’s residential sector

A simulation model was developed for energy consumption in Japan’s residential sector. This model classifies households into 912 categories by household type, building type, and house insulation level. The total energy consumption in the Japanese residential sector was evaluated along with the effect of introducing various energy saving systems, including introducing new-generation water heaters such as heat pumps, cogeneration, and other systems. Except for photovoltaic generation, these systems are competitive.

On predicting the magnitude and temporal variation of cooling loads in detached residential buildings

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.

Study on simulation modelling strategy for predicting thermal energy demand profiles of residential complex

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.

Impact of window design variants on lighting and cooling loads: clues for revisiting local building regulations

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.

Practical method to model trees for daylighting simulation using hemispherical photography

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.

Computational simulations for predicting vertical daylight levels in atrium buildings

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.

Applications of image based rendering in lighting simulation: development and evaluation of image based sky models

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.

Performance evaluation of PV ventilated glazing

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.

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