Energy efficient design in energy usage has to do with counterchecking that a building utilizes energy within it in a manner that is not ruinous, but rather in a manner that is ordered and controlled. By so doing, a construction can achieve huge economies in the course of its lifespan through using less energy in its operations.
Energy Efficiency, Passive Air Flow Principles for Ventilation and Thermal Comfort.
the stack effect
In the developed world, plenty of buildings have been designed with an emphasis on provision of space that maximizes on views and optimal space usage. This philosophy of design means that emphasis is placed on office usable areas and ancillary spaces may be zoned near building central cores, distant from natural light and ventilation. These spaces therefore have to rely on mechanical ventilation for them to work.
Reliance on artificial ventilation may not be energy efficient design
One major weakness of having systems that are wholly reliant on energy to work is the fact that if there is a power failure, these systems would fail. The result of this is that there would be huge inconveniences due to smell and lack of ventilation in these spaces which are served by artificial ventilation systems.
Buildings must provide adequate air flow within them mainly for two reasons – provision of fresh air which is a basic life necessity, and to regulate interior temperatures by retaining it within human comfort levels. Any artificial ventilation systems or mechanical ventilation that is installed within a building seeks to ensure that there is proper airflow and comfortable indoor environmental quality through the quality of air experienced within.
Buildings today are more spacious and sophisticated than during previous times, with many builders placing emphasis on creation of large interior lettable spaces to maximize rental incomes. This has led to many a building being constructed with little regard for natural ventilation systems. Rather due to their size and internal orientation many tend to rely on mechanical ventilation systems. Many malls for example are completely internally oriented, with fewer openings on the periphery. Some offices may offer large windows simply to maximize on views and internal lighting rather than providing much ventilation.
Design trends that shun natural ventilation methods invariably place a major demand on the need to artificially enhance the flow of fresh and clean air within the interiors of such buildings. The means to achieve this is use of artificial air conditioning systems that will circulate air within building interiors. However, these systems require the provision of continuous energy supply, and this can be a substantial cost to cater for during the life of the building.
Energy Efficient Design – Ventilation Using The Stack Effect
Hot air rises, while colder air falls. This principle of nature is what is applied using the chimney effect, as hot air that has been warmed by occupants within buildings can be provided with a vertical channel with which it can flow upwards and outwards. As this happens, cooler air is naturally drawn in at the base levels of a space to fill in the vacuum that has been left by the escaping warmer air upwards. This creates a natural heat exchange process using air.The chimney effect is achieved simply by having an vertical shaft or expanse within a building that extends right to its top. This is connected to low level inlets or ventilation shafts, all of which connect to the vertical shaft. This could be an atrium or light well, having an opening at its apex. Warm air rises through this shaft to the top, and is emitted into the atmosphere at its top. In the meanwhile cool air is drawn into the building from the low level inlets to fill in the vacuum left by the warm air, and so creates a cooling effect within the building.
With the upward movement of warm air in the building, a low pressure zone is created at the lower end of the building. This is immediately filled by nature as it equalizes low pressure by pushing in cold air from without. This leads to creation of an air flow cycle which exchanges heat within the building naturally. Cool areas at the base of the atrium can be used for shopping or eating spaces.
Use of the chimney effect can be effected in various climatic conditions, all with the need to reduce the need to rely on artificial air conditioning. Temperate countries can use this to regulate building interior temperatures during warm summers, while tropical conditions can allow this to be used throughout the year. In so doing, a building’s running costs can be greatly reduced as one is able to achieve good interior environmental comfort using natural air flow systems. This greatly enhances a building’s sustainability. The principle of using natural modes of ventilation in order to create an energy efficient design can be seen at work here.
