English

Shading devices used to protect from unwanted solar radiation acting on interior surfaces change air velocity and volume flow rates depending on their geometry and position on the building exterior. Changes in volume flow rates, interior velocities and the amount of solar radiation can be advantageous or disadvantageous depending on the time of day.

The use of operable shading devices impacts building loads significantly. The need exists for an explicit treatment of window shading devices in the design of energy efficient buildings through simulation. A general framework for modeling complex fenestration systems has recently been implemented in ESP-r. The underlying models have been developed with emphasis on computational efficiency and straightforward input requirements.

This study compares three different control strategies for double-skin systems. The analyzed control strategies are (1) rule-based approach, (2) exhaustive search and (3) gradient-based search. The fundamental principle of the rule-based approach is “if this, do that” under certain circumstances, and the rules are generally based on expert knowledge. The disadvantage of this approach is that it does not reflect the transient behaviour of the system.

This paper deals with the calibration of models capa-ble of simulating the performance of MicroShadeTM. The function of MicroShade is similar to Venetian blinds, however, MicroShade is a microstructure em-bedded in a metal foil with a thickness of less than one mm. MicroShade has been modelled using a novel module in ESP-r for modelling bidirectional transmission through transparent multilayered con-structions. Windows with and without MicroShade have been tested in two dedicated test rooms. The measurements from the test rooms have been used to calibrate the model of MicroShade.

Solar shading can be used to decrease the cooling power demand and cooling energy use but that also reduces the possible benefit for heating with the incoming solar radiation when there is a heating need. The apparent solution is to shade when there is a cooling need and allow solar gains when there is a heating need. This paper presents energy use simulations on such a system set up in a theoretical office cell and a theoretical apartment in southern Sweden showing remarkable decrease in energy use for heating and cooling, or too high over indoor temperatures.

In non-residential buildings, comfort and energy demand for heating, cooling and lighting are significantly influenced by the façade.  Up to now, only non-weighted luminance-based methods for calculating and evaluating annual daylight glare exist (Lee et al., 2005; Mardaljevic and Lomas., 1998). Within this paper, different methods based on the daylight glare probability DGP (Wienold and Christoffersen, 2006) for a dynamic calculation of glare are discussed and evaluated: 

1. Timestep by timestep calculation –RADIANCE reference method.

This paper proposes an interactive goal-based method for designing daylit buildings.  The lighting simulation tool which supports this process is a hybrid global illumination rendering method which efficiently computes annual daylighting metrics.  The goal-based method uses a knowledge base populated using a set of previously completed simulations that quantify the effects of various façade design modifications.  The knowledge base guides a simple algorithm over an iterative design process.

This paper provides an overview of a new method for modelling the total solar energy transmittance. It is implemented in the ESP-r building simulation program to model complex façades such as double glazed façades with external, internal or integrated shading devices. This new model has been validated and tested for several cases.

Fenestration and its design have a significant impact on the energy use associated with the artificial lighting, heating and cooling of a building. To date, research into window optimization has been for windows that are constrained to have a regular geometric shape and position. This paper describes an approach in which a building façade is divided into a number of cells, each cell having one of two possible states, a solid wall construction, or a window.

The objective of this work is to evaluate the quality of the predictions of the indoor airflow behaviour by the zonal method in comparison to the CFD results. The isothermal airflow of the International Energy Agency Annex 20 test cell was chosen to perform the proposed comparative analysis. This cell represents a rectangular room where the air is supplied horizontally on the upper left and is exhausted through an opening located on the lower right on the opposite side.