Why Do Buildings Need Electricity?
In terms of thermal comfort (heating or cooling) and air quality, most of the energy used in buildings is used to maintain a comfortable indoor environment (ventilation). Other applications of energy include electric lighting, hot water, kitchen appliances or other electrical equipment (refrigerators, computers, TVs etc.).
Though energy consumption for heating has been reduced in Denmark over the last four decades due to legislative efforts, electricity consumption has increased in the last four decades (Marsh et al., 2006). In the rest of the western world, similar trends in energy use are likely to be observed. This is due to an increased number of consumer electronic products, such as televisions, laptops, stereos, portable music players, etc., which, aside from stand-by consumption, are not protected by energy conservation legislation.
When constructing a building or preparing for refurbishing, it is important to use energy-efficient solutions, and maybe even more important to do so without compromising the quality of the indoor climate. Buildings are essentially designed to shield us from the weather and keep us warm and safe. Nonetheless, careful architecture will substantially reduce energy demand.
Power Distribution in Large Buildings
Large buildings have a much higher electrical load than small buildings; the electrical equipment must therefore be bigger and heavier. Since it comes at a cheaper cost, large building owners can also buy electricity at high voltages (in the US, 13.8kV). The owner can have and manage their own step-down transformer in this situation, which decreases the voltage to a more functional level (480/277 volts in the US). It is possible to install this transformer on a pad outside the building or in a transformer room inside the building.
It then transmits the electricity to the switchgear. The task of the switchgear is to safely and efficiently distribute electricity throughout the building to the various electrical closets. The equipment has various safety features, including circuit breakers, which allow downstream power to be interrupted – this can occur due to a malfunction or issue, but it may also be done deliberately to allow technicians to work on particular power system branches.
It should be remembered that there may be multiple transformers in very large buildings or buildings with complicated electrical systems, which may feed multiple pieces of switchgear. By sharing the basic concepts, we are keeping this article short.
The power leaves the switchgear and moves along a main feeder or bus. The bus or feeder is a heavy gauge conductor that can safely and effectively carry high-amperage current in a house. As necessary, the bus or feeder is tapped and a conductor is driven to an electric closet that serves a building area or floor.
Every electrical closet will have another step-down transformer – in the US, for convenience outlets, this will lower the power from 480/277 volts to 120 volts. A branch panel, which regulates a series of branch circuits that cover a portion of the house, will feed the transformer. Every branch circuit covers a sub-set of the area’s electrical needs, such as lighting, convenience outlets for a number of rooms, or electricity for a piece of equipment.