10 steps to an energy-efficient building
Based on the book "Sustainable building services" principles, systems and concepts, by Bernhard Lenz, Jurger Schreiber, Thomas Stark. The development of an energy concept includes the understanding of two complementary objectives, the first objective is to minimize the demand for energy and the second is to optimize the energy supplement by implementing sustainable structural measures.
The structure, construction and materials should be coordinates during an early planning phase in a way that enables the building to offer a comfortable room climate without any substantial technical support for as long as possible. This means that components of a build should not be selected merely for their structural, functional or aesthetical characteristics, ideally should also offer additional benefits in terms of energy use (building component activation). The challenge, apart from the utilization of of synergy effects, is to find creative solutions for conflicting objectives such as compactness versus use of daylight or transparency versus summer heat protection.
Step 1+2: Conversing and supplying heat efficiently
Controlling heat is one of the most important services when it comes to build, during periods of heating the most important thing is to retain heat inside the building. Despite all the efforts it is always necessary to add a heating system, to provide an efficient way to produce, store, transfer and distribute heat. Consider that to generate this heat potential, we must use renewable energies and generate the lowest level of carbon, or a even carbon-neutral master plan.
Step 3+4: Avoiding overheating and dissipating heat efficiency
If cooling is required or requested, the same requirements and possibilities apply as for the heat supply in that, if possible, the access heat should be removed in a carbon-neutral way. Systems that use the the cooling potential of the ground and the ground water or solar energy for cooling purposes are environmentally beneficial.
Active systems are required for larger cooling loads. Apart from the efficient electrical refrigeration machines, witch can ideally be run on regenerative power, the application of sorption-assisted systems is an interesting for cooling a building. If the heat to drive the cooling process is exclusively or mainly produced by solar thermal systems, the system is referred to as direct solar cooling. If cooling loads and solar gains occur simultaneously, the cooling medium can be supplied in a carbon-neutral way and with little demand of storage.
Step 5+6: Neutral ventilation and supplying air efficiently with mechanical support
Good air quality in building requires a regulated air exchange related to the use use of the space and the number of people occupying it. Today's construction methods produce high degrees of air tightness; an uncontrolled air exchange thru joints and gaps is largely prevented. For this reason is necessary to plan ventilation systems carefully by using either the building envelope or technical building equipment.
There are numerous systems using differing methods to convey and treat air. Decentralized mechanical ventilation units using the building envelope allowing a constant air exchange rate without air ducts.
Step 7+8: Using daylight and optimizing the use of artificial light
In order to optimize the light concept from an energy perspective, there are generally three relevant planning aspects: lighting technology, lighting concept and light automation. The choice of lighting product has significant impact on the electric power demand. The efficiency (luminous efficiency), measured in lumens per watt of connected of connected load, sometimes differs considerably. What is more, a low luminous efficacy leads to greater heat development witch in turn affects the internal heat load of the building.
The aim of automation is primary to increase the user's level of comfort. In addition, the are high saving potentials in the power consumption of lighting due to a reduction of full-load hours. The degree automation has to be determined by balancing the two target values, the energy saving and the users satisfaction.
Step 9+10: Applying efficient equipment and generalizing power in decentralized plans
The demand for electric power, over and above that for artificial lighting, cooling and ventilation, is generally determined by the user's needs and the electrical equipment they require. The goal here, apart from planning the building in a optimal way, is to ensure that users install a energy-efficient equipment, wherever possible. The overall aim, is not to operate the building off the grid, but to archive a neutral energy balance over the course of a year.
Photovoltaic and combined heat and power plans are well-developed systems for the decentralized generation of electric power, which are immediately linked to the planning of the building. There are further important technologies that have not yet been integrated in buildings, but may be a source of value in the future (solar thermal power generation, wind energy, water power, etc.).
At the present time the energetic efficiency, is based on the saving of the energy, related in the majority of cases for A/C, or artificial energy. Lately I've been thinking that we could transform energy in different ways, like the kinetic energy that we generate when we walk, if we put turbines in the buildings and when its rain or windy that make them turn, that you can go to a gym and they pay for generating energy. But I know that they are energies that will be implemented in the future so it is not too much to consider them, for a crazy project or that is not profitable for the actual context.
As a review of the book I can say that it is very complete and I strongly recommend it if you are looking for principles, systems and sustainable concepts. It was produced by Germans so they know about climate change, thermal conductivity, and how to adapt a system to different seasons of the year.
And remember the main concept for development:
Minimizing the energy demand for optimizing the energy supply and and vice versa.
