IBPSA2009

Subtask 1 of the IEA ECBCS Annex 41 (IEA 2007) project had the purpose to advance development in modelling of integral Heat, Air and Moisture (HAM) transfer processes that take place in “whole buildings”. Such modelling considers all relevant elements of buildings: The indoor air, building envelope, inside constructions, furnishing, systems and users. The building elements interact with each other and with the outside climate.

Building physics processes in some parts and elements of revitalized historical buildings play an important role in their future energy efficiency and maintenance. The unique character of 100-years-old post-industrial buildings results from masonry-brick façades with precise ornamentation and sophisticated details which should be retained and reconstructed in renovation works. Any changes in wall properties, such as the addition of new layers (insulation, rendering or plaster), are at variance with cultural heritage protection.

This paper gives an onset to whole building hygrothermal modelling of the interaction between interior and exterior climates via building enclosures, which even takes into account wind-driven rain (WDR). First, the temporal and spatial distribution of WDR on the facades of a single leaf brick wall building is numerically determined. Then the hygrothermal behaviour of the walls and the room zone is numerically analysed. The results show that WDR loads can have significant impacts on the indoor climate, energy consumption and mould growth risk.

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.

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.

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.

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.