The subject of energy efficiency has given rise to many studies, seminars, courses, reports and articles, but above all it has aroused the curiosity of all those who care about environmental issues, in an attempt to unite progress to an efficient use of the available resources.

If we take into account that the majority of us work in buildings the project and construction of which were not prepared to be energy efficient, or at least to achieve very low levels of energy consumption, then the work and effort to reduce energy use becomes even more difficult.

Buildings in general consume 40% of all energy use, and are responsible for 21% of gas emissions that provoke the greenhouse effect on the world level, which in turn will influence climate change. The increase in the cost of energy, awareness in relation to environmental concerns and new laws require us to adopt new strategies towards sustained reduction of consumption, noxious emissions and the inherent costs.

Factors of energy efficiency in buildings vary according to the geography, climate, type of construction and location. The aim will always be the designing of energy efficient buildings, involving innovating engineering solutions and systems of control and monitoring. However, current legislation covers both newly built buildings and those that already exist. Currently in force is a set of legal diplomas related to automation, energy management and quality of inside air, which resulted from the transposing of the European Directive (EPDB) 2002/91/CE of the 16th of December 2002. The Portuguese diplomas created for the transposition are:
– Decree-Law 78/2006 of the 4th of April, approves the national System of Energy Certification and Inside Air Quality in Buildings;
– Decree-Law 79/2006 of the 4th of April, approves the Regulating of the Energy Systems and Acclimatisation of Buildings;
– Decree-Law 80/2006 of the 4th of April, approves the Regulating of the Characteristics of Thermal Behaviour of Buildings.

It is vital for energy efficiency to be applied to all levels and not only to more sophisticated properties. We are dealing with new impositions and guidelines to which we have to correspond, whether through the implementation of a centralised system of management or through better solutions in the choice of installations, or through awareness-raising for all those who collaborate in and use buildings aiming at a better and greater rationalistation of resources.

The Egas Moniz Building (EEM) in the Faculty of Medicine of the University of Lisbon (FMUL) has been working since April 2004. Although at the time of its project and then during its construction there was no obligation to follow legislation in the area of energy efficiency and the quality of inside air, this is no longer true today. What follows are some considerations about their installation from the energy point of view.

Evolution of Energy Consumption in the EEM (2006 to 2008)

As we can see in the chart, electrical energy consumption increased in 2008 in relation to the previous year, an increase which is mainly due to an increasing number of collaborators in the building due to the arrival of new research units accepted by the Institute of Molecular Medicine and the FMUL, which has led to a growing increase in the equipment installed and greater needs for acclimatization and ventilation.

System of Technical Management
The EEM possesses a system of Centralised Technical Management that allows one to regulate a part of the lighting and acclimatisation system according to the light conditions throughout the day, the night and day periods, according to the needs for heating comfort during the different seasons of the year. The FMUL’s aim is to improve the capacities of this system for it to take on a determining role in the efficient management of energy consumption. The system was recently improved in order to reduce energy consumption through installing network analysers that will allow a registering, analysis and respective monitoring of the building’s energy consumption.

Acclimatisation and Ventilation
Most of the building possesses a centralised acclimatisation system, with individual equipment, fains coils, with manual settings, and which can be turned on and off and regulated by the users. Only the common areas, the Main Auditorium and the amphitheatres, are regulated through a centralized management system. The heating, cooling and ventilation systems (air renewal) are the main systems responsible for consumption of energy in buildings, a consumption that is associated to the demands of thermal comfort and good working conditions for the different activities.

Lighting
On the level of the indoor lighting, one of the main measures that had already been adopted was the use of fluorescent bulbs and in all the common spaces the use of compact, tubular, fluorescent low-consumption bulbs, as well as the replacement of inefficient ballasts by electronic ballasts. Presence-sensitive sensors were also set up in the restrooms and corridors.

The EEM has a reflective film on the windows with greater exposure to the sun, in order to reduce the thermal charge of the building and thus to diminish the consumption of energy of the acclimatisation system. In some windows, which receive most sunlight, white blackout curtains have been installed. These, along with the film coating, will block out the harmful ultraviolet rays and the uncomfortable heat of the sun, in order to improve the room temperature.
The light colours that cover the outside walls of the building represent a low capacity for heat absorption.

These are some examples of measures aiming at a more efficient use of energy, as it is not always necessary to make a very high investment. It involves small touches like unplugging all the devices that don’t need to be connected, turning off those on stand-by or on sleep, using natural light instead of artificial light whenever possible, opening the windows in the morning and closing them during the hours of greatest heat in the summer, always checking whether the doors to freezer chambers are closed, and turning off the lights when one leaves a room.

All of these small gestures may seem insignificant, but they are measures that can be carried out by everyone, and which in a whole population may make a difference. It is not enough to find technologically advanced measures or introduce new systems and equipment if there is not a change in behaviour with a view to a rationalisation of resources and better use of the existing conditions, although these are not always the best.

Energy certification is now a compulsory reality for all buildings, but the true application of which will only be possible to reach if we can change behaviour patterns and habits from our daily lives, whether this be at work, at home or in other environments. Obviously there is no magic formula for us to manage to drastically diminish the consumption of and dependence on electric energy without lowering our patterns of comfort and demand that we have become used to; yet, change is approaching.

If you think that in being only a user of the building in which you work means not having to pay the energy bill at the end of the month, you are wrong, because the emissions produced by the fossil fuels used to satisfy the increasing energy needs for each building on a global level are provoking dangerous climate changes for the planet. The consequences of global warming are frightening, and may become catastrophic.

If we take into account all the changes that are taking place on the level of Public administration in Portugal, we will see that the matter of efficiency is not only restricted to energy consumption; efficiency is increasingly related to strategic aims for change, as is efficiency in the acquisition process of public goods and services, operational efficiency, efficiency in information management, thus leading to an ever-increasing need to add value to the Public Service, promoting change in values and behaviour.

A building has a long life cycle, so its effect on the environment is a long and continuous problem to be considered. (ONG, China)

Bibliography:

A Utilização Racional de Energia nos Edifícios Públicos, May 2008, Guia Informativo EnerBuilding.eu, cit. in ADENE and DECO.

Eficiência Energética em Edifícios, Realidades Empresariais e Oportunidades (2009). Synthesis Report BCSD Portugal

Márcia Martins Vila
Unidade de Gestão Edifício Egas Moniz
47041
mvila@fm.ul.pt