The key to sustainable buildings Why and how to use natural ventilation in your building design ← Back to index 2 Content Preface 4 Why should night purging be incorporated 25 into your building? Introduction 5 In which climates is night purge ventilation 25 most effective? Why consider natural ventilation? 5 Common concerns with night purge ventilation 25 Natural ventilation 6 Selecting the right window 26 So, what is natural ventilation? 6 actuators Indoor air quality indicators 7 What is an actuator and what is its purpose? 27 Natural ventilation advantages 8 How do actuators differ? 27 The advantages in a nutshell 9 Wiring routes and concealment 28 Productivity and Health benefits 10 Multi speed operation 29 Productivity and Health benefits – the practical Pressure safety function 29 implications 12 Actuator position feedback 29 Economic impact of natural- and hybrid ventilation 12 Synchronised actuators 29 Improved use of space 14 Opening areas 30 What kind of buildings can benefit from 15 using natural ventilation? Window orientation 31 Natural ventilation principles 16 Compiling a specification to avoid 31 common complaints Single-sided ventilation 17 Green certifications 32 Cross ventilation 17 Stack ventilation 17 Project examples 33 Natural ventilation design 18 Get in touch 43 Intelligent control systems for natural ventilation 22 References 43 Night purge ventilation 24 Night purging using natural ventilation 24 – how does it work? 3 ← Back to index Preface Natural ventilation has always been at the heart of around energy, CO2 emissions and the efficient use WindowMaster. By making buildings breath and bringing of resources. These are all crucial for our life on this fresh air into schools, workplaces and other buildings, planet; yet they only compose three factors on the whole WindowMaster has helped to focus attention on what spectrum of issues facing us in our pursuance for living really matters: A sustainable and healthy climate – inside good, viable lives. as well as outside. A comfortable indoor climate with the optimum amount of By implementing natural ventilation to almost all types fresh air is equally important for our health and well-being. of buildings, we have created spaces of high quality and And with our health and well-being making up essential increased the well-being of occupants all whilst increasing parameters to the overall quality of our lives, it is of the room for design and actual usage by reducing the utmost importance that we make indoor environment part area needed for mechanical installations. Today, we of the public discussion and raise it to the same level as experience that WindowMaster’s products and solutions the questions pertaining to the human impact on outdoor are more pertinent to the market than ever before. environment and sustainability. Together with aesthetically designed rooms, health and well-being constitute one of the most important agendas With natural ventilation, indoor and outdoor environmental of the future together with an increased focus on energy issues can be addressed concomitantly while putting full savings. focus on the architectural design of a building. In recent years, the public discourse on sustainable architecture, and sustainability in general, has revolved WindowMaster project: Gentofte Hospital 4 ← Back to index WindowMaster project: Frederiksberg shopping center Introduction Why consider natural ventilation? Imagine you could reduce a building’s area used for With this e-book, we aim to share our knowledge on ventilation by 90%[1], what would be the impact on your sustainable ventilation architecture by offering specific design and final performance of that building? advice and documentation on the effects and advantages of WindowMaster products. You will learn how natural This eBook has been written to address some of the ventilation can be used to create beautiful, healthy issues and opportunities that Architects worldwide face buildings that are good for both the indoor and outdoor when designing buildings that needs to be ventilated climate. You will discover ways in which natural ventilation and meet sustainable requirements. Chunky ventilations can be applied to new as well as old buildings, to make taking up space that could have been used for more them more sustainable. And you will learn how to use aesthetically designed rooms, unnecessary energy the principles of natural ventilation architecture to make consumption as a result of ventilation systems, high complete use of your space, reduce construction costs maintenance costs and noisy mechanical fans. If these and increase your green energy rating. issues sound familiar, this e-book is for you. 5 ← Back to index Natural ventilation So, what is natural ventilation? Natural ventilation is the use of natural forces, including ventilation is achieved by an intelligent system that both wind and thermal buoyancy, to regulate a building's automatically opens and closes windows depending on indoor climate. These forces are created by temperature numerous conditions inside and outside the building, differences between the interior and exterior environment, including outdoor temperature, wind speed, wind thermal displacement within the building and winds direction, rain detection, indoor temperature, relative around the building. Buildings using intelligent natural humidity and CO2 level in the room. ventilation take advantage of the fact that warm air rises. When air rises, it can escape through vents, which in turn Go to page 18 to read more about → lowers the internal temperature. the design of natural ventilation The air inside a naturally ventilated building is kept fresh by controlling air change, typically by using actuated windows in the building's facade and/or roof. Ideal WindowMaster project: West Suffolk House, drawing of ventilation principle 6 ← Back to index Indoor air quality indicators Natural ventilation is an efficient way to control the indoor air quality. To better comprehend the impact of indoor An average person breathes air quality and why it is important to control, consider the approximately 15 kg of air each day amount of air we breathe per day. An average person compared to consuming 2 kg of consumes 2 kg of food and liquids per day, but breathes approximately 15 kg of air per day (corresponding to food and liquids 12,000 liters). 90% of our time is spent indoors, meaning that most of the air we breathe comes from an indoor health conditions. Source control and the use of environment[2]. ventilation to dilute contaminants are the primary methods for enhancing indoor air quality in most buildings. According to Professor Jan Sundell of the International Centre for Indoor Environment and Energy at DTU (the Today, several indicators exist to measure indoor air Technical University of Denmark) “there is much evidence quality and the level of those pollutants. Greenhouse that the indoor environment, especially dampness and gas emissions or Carbon dioxide (CO2) is one of the inadequate ventilation, plays a major role from a public most commonly used indicators, measuring the CO2 health perspective, and that the economic gains to society produced by human breathing and emitted by appliances. for improving indoor environments by far exceeds the Other indicators include humidity and volatile organic costs” [3]. Accordingly, it is vital to look at metrics that compounds (VOCs). indicate the quality of the indoor air to be able to read and control the air we breathe. TOP TIP: To design a building with Indoor air contains many pollutants and can be affected a comfortable indoor climate make by gases (including carbon monoxide, radon and volatile sure to keep down levels of VOC, organic compounds), particulates, microbial contaminants, CO2 and humidity or any mass or energy stressor that can induce adverse 7 ← Back to index Natural ventilation advantages As already stated in the beginning of this e-book, natural ventilation comes with many advantages ranging from environmental benefits to improved design and lastly an enhanced indoor air quality that battles high levels of CO2, VOCs and humidity. In the following sections, we will sum up some of the key reasons why every architect should not design a new building or retrofit an old building without first considering implementing natural ventilation. 8 ← Back to index The advantages in a nutshell 1. Beautiful architecture Natural ventilation is the obvious choice when replacing No unsightly pipework or duct penetrations and no bulky old windows with new ones simply by installing actuators ventilation units. Ceiling heights can be increased, as to control the ventilation process. natural ventilation does not require suspended ceilings. More daylight and transparency, including the use of 7. Fast renovations atriums for natural ventilation. With natural ventilation, the renovations can be completed very quickly, thus causing minimal disruption to the lives 2. Lower energy consumption of the building occupants. Often it is also possible to avoid Natural ventilation consumes less energy than a having to relocate the occupants of a building during the comparable mechanical ventilation system. The use of renovation period. mixed mode ventilation can potentially reduce energy consumption even further. 8. Lower costs The need for fewer and less expensive components 3. 100% use of space and construction work makes natural ventilation a cost- Natural ventilation enables full utilization of the building effective option for achieving a better indoor climate. floor plate and floor to ceiling height, as there’s no need Over a building’s life cycle, capital costs, operating costs, to devote space to large air handling units and equipment and maintenance costs are 5 times lower with natural rooms. ventilation compared to mechanical ventilation and 2.5 A mechanical ventilation system occupies up to 6.5% of a times lower with hybrid/mixed mode ventilation.[7] building’s floor area compared to only 0.2% for a natural Our systems pay for themselves within less than a year, ventilation system.[4] resulting in an average ROI of at least 120% for natural ventilation and mixed mode systems, thanks to energy, 4.