Spotlight
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Naturally healthy H
Dr Owen Connick
ealth and wellbeing equals productivity… The World Green Building Council report ‘Health, Wellbeing and Productivity in
Offices: The next chapter for green building’ has shown the importance of office design and how it impacts on the health, wellbeing and productivity of its occupants. Within the report it highlights that the health and productivity benefits of good indoor air quality (IAQ) are well established. A comprehensive body of research was drawn on and suggests that productivity improvements of 8-11% are not uncommon as a result of better IAQ. But modern, air-tight buildings present issues for
IAQ. Whilst this is advantageous for the energy efficiency of a building, without appropriate ventilation they are prone to the accumulation of air pollutants, resulting in poor IAQ. Airtight buildings can also overheat, with excessively high workplace temperatures also impacting IAQ, reducing productivity and causing fatigue, irritability, and headache. So what can be done to improve IAQ and so productivity and wellbeing?
Ventilation, naturally
Ventilation in buildings is crucial in providing occupants with a healthy and comfortable environment. Natural ventilation uses the forces of wind and buoyancy to help air move naturally through a building, rather than using fans to push the air around, using 60% less energy in the process. There are many benefits of using natural ventilation; it is natural, healthy, improves indoor air quality, and is both low maintenance and low energy. However, problems can occur if a system is poorly designed or if it is not suitable for the building. When it is warm outside naturally ventilated buildings can overheat and when it is lower than 16°C outside, it is too cold to bring outside air directly onto occupants. There are solutions to these problems. Breathing Buildings overcomes these issues through its system design. In summer, fresh air enters through open windows cooling the space, the heated air is displaced upwards and air is exhausted at a high level. And in
A leader in sustainable buildings
sustainability rating for an office building at design-stage. It is hoped that the building will serve as a stimulus for other projects in London with similar ambitions. The objective here was to create a stunning building in every sense – an incredible place to work, a beautiful building architecturally, but also one which is truly sustainable. The project fuses low-energy natural ventilation with supplementary hybrid- mechanical ventilation, such that energy usage is minimised whilst thermal comfort and air quality are ensured throughout the range of external weather conditions experienced in London’s typical British climate. Flexibility in design and adaptability of this kind are crucial features of new buildings if they are to be resilient to both predictable and unpredictable changes in climate over the coming years and decades. Breathing Buildings is proud to have supported the sustainability team at Foster+Partners during
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the early and detailed design stages of the project. An in-depth study was undertaken at early design stage to investigate flow patterns within and between internal floors of the building. Physical water bath modelling was used to visualise flow paths, forming a key part of the design team’s efforts to establish the range of flow regimes which may be exhibited. To view the project, follow the link:
www.youtube.com/watch?v=BkI035BaowI
he recently completed Bloomberg headquarters in London has set a new world record BREEAM ‘Outstanding’
Hybrid ventilation
Hybrid ventilation goes one step further by utilising both natural ventilation and mechanical ventilation in one system design to optimise indoor air quality, comfort and energy efficiency. This type of system uses the different features from natural and mechanical ventilation at different times of the day or season of the year to produce the best outcome. With hybrid ventilation the active mode reflects the external environment and takes maximum advantage of ambient conditions at any point in time with an intelligent control system that can switch automatically between natural and mechanical modes in order to minimise energy consumption. In terms of occupant comfort, a hybrid ventilation
system is a very attractive concept. Natural ventilation is used for the majority of occupied hours but can be assisted or amplified by mechanical systems under peak heating or cooling conditions thereby accommodating greater extremes of internal heat gains and external temperature fluctuations. The result is that energy consumption is minimised under normal day-to-day conditions, whilst ensuring sufficient ventilation capacity under a wide range of internal/external scenarios.
Hybrid ventilation fulfils the high requirements for indoor environmental performance and the increasing need for energy savings and sustainable development by optimising the balance between IAQ, thermal comfort, energy use and environmental impact.
Trends
Today very few modern buildings are purely naturally ventilated. In fact there is a growing adoption of hybrid ventilation in buildings that already have single sided natural ventilation, thus allowing occupiers to benefit from improved indoor air quality and thermal comfort. This trend is particularly growing in refurbishment projects such as Victorian buildings. Here previously naturally ventilated properties can benefit from hybrid ventilation bringing the buildings up to modern
10 April 2018
As health and wellbeing moves up on the agenda for employers it is becoming increasingly important to create a healthy and comfortable building for employees. At the same time building owners are always keen to drive energy efficiency to cut bills. Dr Owen Connick, consulting manager at Breathing Buildings explains how, by employing hybrid ventilation, building owners can maximise health, comfort and sustainability
winter, as outdoor temperatures fall, windows are closed to prevent cold draughts, fresh air enters at a high level and is mixed with warm room air to pre-heat the fresh air.
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