Hendrik Voll

A method of optimizing fenestration design for daylighting to reduce heating and cooling loads in offices

AbstractModern office building designs tend to increase the window share per facade to make the building more impressive with extensive visibility and well daylit rooms. In general, an increased window share results in higher energy usage and higher costs of heating and cooling, but these disadvantages can be reduced with a more careful design. The aim of this paper is to show the influence of window design and room layout on heating and cooling demand and daylight availability in office buildings in northern Europe. The results in the paper are based on design calculations for two different room types and daylight measurements on two room scale models in a daylight laboratory. The calculations show the influence of window design parameters on the cooling and heating demand. The daylight measurements show the influence of window design parameters on the availability of daylight. The results have then been combined to show a feasible window design regarding daylight availability and the resulting cooling a...

Horizontal or vertical? Windows’ layout selection for shading devices optimization

Purpose The purpose of this paper is to constitute an efficient way to improve energy efficiency and occupants comfort in buildings through reduction of direct solar heat gains by exterior shading devices. The shadings orientation and layout depends on the building location and facade orientation, and influence consequently the windows layout. It is still debated which type of window layout is preferable for a specific building location and facade orientation. Design/methodology/approach The paper presents a method to determine the most efficient windows’ layout, horizontal or vertical, for shading devices optimization by mean of integrating energy simulations and computational design. A parametric model has been built by visual programming language to simulate, iterate and compare the results. Findings The research shows the most efficient layouts of windows to be shaded for three latitudes and locations, and the 16 cardinal directions, to be used by architects and designers. The results show a significant prevalence of the horizontal window type on the south facades but also on the east and west orientations for all the three locations, while the rules of thumb would suggest the vertical layout for the sunrise and sunset facades. Originality/value The task of designing exterior shading devices presents two main issues: the shading period selection and the method of calculating its size and shape. The present research uses the innovative method Shaderade that existing literature demonstrates superior comparing other more dated like the section method and the solar vectors one.

Analysis of the insolation criteria for nearly-zero energy buildings in Estonia

Nearly-zero energy building features have great impact on the overheating of residential premises under various urban conditions in which the building meets the applicable insolation criteria in Estonia. Different building regulations require measures that often conflict with each other. The features necessary for the energy consumption required for nearly-zero energy buildings, the distance required for the buildings to guarantee the minimum insolation hours, and the maximum quantity of degree-hour in the mandatory period are characteristics that need to be carefully integrated; otherwise, the achievement of one or two could prevent the possibility of satisfying the others. Have been studied variations of internal temperatures in a residential premises located in Tallinn, Estonia, with different orientations and neighboring building distances, on different floors and in the different configurations of windows closed, with windows opened and with shadings. The outcomes show that a nearly-zero energy building, when located at a distance from the surrounding buildings that fulfils the insolation criteria, dramatically exceeds the maximum number of degree-hours. This would lead to the need for additional energy in order to cool the residential premises, so to compromise the fulfilling of nearly-zero energy buildings consumption target, or to the use of passive strategies. The use of natural ventilation, in addition to mechanical ventilation, or operable external shadings, decrease significantly the variations of interior temperature and maximum degree-hour, that in most part of the cases fulfill the requirements. Therefore in nearly-zero energy buildings passive strategies are mandatory also in Northern latitudes and the different requirements for daylight standard, indoor temperature and energy consumption must be carefully integrated in order to yield a design that could fulfill them.

Urban planning principles of nearly zero-energy residential buildings in Estonia

Purpose The purpose of this paper is to propose a scientific method to evaluate possible urban layouts of a test building integrating building regulations, natural light standard and energy requirements to achieve nearly zero-energy buildings in Estonia. The integration of building regulations, energy requirements and natural light standards is crucial to evaluate the incidence of the surrounding environment when analyzing the energy performance of buildings. Design/methodology/approach The paper investigates the variations of the energy consumption of a model building with different orientations and variable urban surroundings configurations for the latitude of Tallinn. The different urban configurations are due to combinations of the different building requirements of fire safety, daylighting and insolation hours that in Estonia affect the layout of residential districts, thus influencing significantly the potential consumption of buildings. Different layouts of surrounding buildings have been chosen all guaranteeing at different degrees the fulfillment of the building requirements for the test building and energy simulations have been run to find the urban layouts that guarantee best performances. Findings The outcomes show that the test building interior temperatures and energy performances vary significantly in the different urban planning configurations and for the different orientations, underlining that is strongly recommended to run always energy simulation of building considering their surrounding environment. The conclusions show the principles to integrate the building regulations to achieve nearly zero-energy districts that significantly can improve life quality in the urban environment. Originality/value The paper analyze the energy efficiency of buildings with different features and orientations simulating their possible urban environment layouts given by building regulations, and not isolated or as built in “an open field” like most of the existing literature in the field.

Daylighting and energy performance design for single floor commercial hall buildings

Purpose Electric lighting accounts for a large share of energy consumption in commercial buildings. Utilization of daylight can significantly help to reduce the need for artificial lighting, increase workers productivity, customers’ satisfaction and consequently improve sales. However, excessive use of glazing and absence of lighting controls can contribute greatly to higher energy need for heating and cooling and cause undesired glare effects. Thus, optimizing the size, position and materials of external glazing, with the addition of deflectors and dynamic artificial lighting, can become key aspects in the design of sustainable low energy buildings. The purpose of this paper is to analyze daylight potential and energy performance of a hall-type commercial building, situated in the cold climate of Finland, by utilizing different combinations of skylights, windows and lighting controls. Design/methodology/approach The authors have used computer simulations to estimate daylight and energy performance of a single floor commercial building in relation to various combinations of skylights and windows with variable glazing materials, light deflectors and zonal lighting controls. Findings The results show that electric light energy saving potential ranges from a negligible 1.9 percent to a significant 58.6 percent in the case of glass skylights and wall windows using multi-zone lighting control. Total delivered energy ranges between increase of 1.5 and 21.2 percent in the cases with single zone lighting control and between decrease of 4.5 percent and increase of 4.5 percent in the cases with multi-zone control. The highest decrease in primary energy consumption was 2.2 percent for single zone and 17.6 percent for multi-zone lighting control. The research underlines the significant potential of electric light energy savings using daylighting strategies that, including the control of direct solar access for glare and internal gains, can be more than 50 percent. Originality/value This research combines accurate daylight and energy assessment for commercial hall buildings based in cold climate region with multiple design variations. The novelty of this work is the consideration of interior elements, shelves and deflectors, in the calculations. This is made possible through the combined use of validated simulation platforms for detailed annual daylighting and electric lighting calculation (Radiance and Daysim) and energy analysis (IDA-ICE, Equa Simulation AB). This method allows to obtain a reliable assessment of the potential of using natural light sources in buildings.

Solar Collection Multi-isosurface Method

Direct solar access and daylight requirements contribute significantly when it comes to shaping the layout and appearance of contemporary cities. Urban planning regulations in Estonia set the minimum amount of direct solar access that existing housing has the right to receive and new premises are required to get when new developments are built. The solar envelope and solar collection methods are used to define the volume and shape of new buildings that allow the due solar rights to the surrounding buildings, in the case of the former, and the portion of the own facades that receive the required direct solar access, in the case of the latter. These methods have been developed over a period of several decades, and present-day CAAD and environmental analysis software permits the generation of solar envelopes and solar collection isosurfaces, although they suffer from limitations. This paper describes an advanced method for generating solar collection isosurfaces and presents evidence that it is significantly more efficient than the existing method for regulation in Estonia’s urban environments.

Free cooling potential of an airside economizer in Estonia

Nearly zero-energy buildings are designed to minimize energy consumption and the low energy demand is to be covered by local renewable energy resources. Free cooling is a method that utilizes low outdoor temperatures as a cooling medium to save energy in air-conditioning systems and is included in nearly zero-energy buildings renewable energy use system boundary. This article explores free cooling potential of direct airside economizer in Estonia. A detailed weather analysis was conducted to develop temperature bin data, which was used to calculate free cooling potential at different ventilation supply air temperatures. The results are presented as yearly, monthly, and hourly airside economizer cooling capacities. Free cooling potential in Estonia is high from October to April, during summer months, airside economizer operation is possible at higher ventilation supply air temperatures.

Basic Design Principles of nZEB Buildings in Scoping and Conceptual Design

nZEB buildings generally require integrated design in order to achieve design targets economically. Decisions and choices in early design stages may be expensive or even impossible to fix later if have not been successful. Massing not supporting energy-efficient design or lack of space for technical systems is typical example of potential drawbacks. It is important continuously to follow that design targets can be met. In early stages, rules of thumb and some key parameters can be used for indirect assessment, which is the method until first energy simulations can be run. Next step is to be sure that planned technical systems can be fitted in the building—there has been enough mechanical space and proper locations enabling energy-efficient design. These and other important milestones in the early stage including fenestration design, shadings and daylight are discussed in this chapter. It is not enough to design a good nZEB building, but it has to be done in a way that the building can be also operated as nZEB building. In majority of projects, designed room layouts will change already during construction, because of clients’ needs. Therefore, the HVAC systems must adapt to changed loads and partition wall locations. To enable flexible space use and adaptive systems, special considerations and the use of room modules are needed, that is, the last but not least issue discussed in this chapter.