1. La agudización de la crisis
1.1 Un congreso que no fue congreso
§ 1.1
Thermal comfort and energy use
According to article 25 of the Universal Declaration of Human Rights of the United Nations, one of the basic human rights is adequate housing for health, well-being and safety. Adequate housing includes the creation of a suitable thermal environment to promote health, well-being and safety. In most countries, to provide the right thermal environment energy should be applied for heating or cooling during various periods of the year. The more the outdoor climate differs from the desirable indoor thermal environment, the more energy the comfort system uses to restore comfort. In total about 8.6% of all energy use in the Netherlands is for heating dwellings which accounts for almost 40 PJ a year and the average newly built home in 2006 uses 25% of the gas for heating of the average home of the entire building stock (CBS, 2014). This shows that much can be gained for newly build homes but especially from retrofitting the existing building stock. There are no numbers on the energy use for cooling in dwellings; however, while the newly built homes with very high insulation tend to overheat in summer, which causes people to install cooling. This makes it crucial to research both heating and cooling season to prevent the energy saving for heating to be frustrated by an increase in consumption of cooling energy.
The Brundtland report "Our common future" (Brundtland et al., 1987) stresses the importance of making sure that this comfort delivery is possible and still will be possible in the future; Therefore, the energy use should be limited as much as possible for the following reasons;
–
The non-renewable energy sources on which most energy supply is depending is becoming depleted and the cost and the impact on the environment increases while it gets harder to harvest the energy resources that lay deeper and more distributed in the ground (IEA,2012).–
By the emission of CO2 (among other things) the use energy from non-renewable energy sources is partly responsible for Global Climate Change, which causes the climates over the world to become more extreme, which can ultimately lead to more need for energy use to compensate for the growing difference between the outdoor climate and the desirable indoor thermal environment (IPCC, 2014).–
The use of renewable resources reduces the use of these non-renewable energy sources. However, although the development of producing renewable energy sources these resources are limited and variable in supply and hard to store which makes it necessary to apply them wisely (IEA,2012).–
As civilisation is advancing, the demand for thermal comfort is increasing, as is the case for any kind of comfort. In the Netherlands this increasing demand on comfort systems for dwellings becomes clear from recent and on-going developments, which ask for certain new concepts in the residential sector. Most of all there is a need of concepts that facilitate adaptability to user specific demand (BouwhulpGroep, 2007).§ 1.1.1
The new stepped strategy
Andy van den Dobbelsteen introduced The New Stepped Strategy (Van Den Dobbelsteen, 2008), a further development of the Trias Energetica order (Lysen, 1996). The New Stepped Strategy adds an important intermediate step in between the reduction in consumption and the development of sustainable sources, and incorporates a waste products strategy. Furthermore, the last step is stimulated to be made redundant.
1 Reduce the demand (using smart and bioclimatic design) 2 Reuse waste flows
3 Use renewable sources and ensure that waste remaining does not disturb the
environment or is used as food
4 Supply the remaining demand cleanly and efficiently
This thesis will mainly focus on step 1 of the New Stepped Strategy, which will make it easier to realise the next steps. To reduce energy demand for comfort, it is important to know when, where and at which level comfort is needed, so no more energy is used than necessary making optimal use of renewable resources.
§ 1.2
Research design
In this thesis, an Adaptive Thermal Comfort System (originally The Adaptive Dwelling (DEPW, 2006)) is defined as the whole of passive and active comfort components of the dwelling that dynamically adapts its settings to varying user comfort demands and weather conditions (seasonal, diurnal and hourly depending on the aspects
adapted), thus providing comfort only where, when and at the level needed by the user, to improve possibilities of harvesting the environmental energy (e.g. solar gain and outdoor air) when available and storing it when abundant ( Figure 1.1).
FIGURE 1.1 The Adaptive Thermal Comfort System for dwellings with the adaptive building characteristics on the right
Figure 1.1 shows the various factors that determine the thermal environment in the Adaptive Thermal Comfort System and consequently the energy use for thermal comfort of the occupants which will be researched in PART 2 of this thesis. The middle of the scheme is the thermal environment together with the control centre of the Adaptive Thermal Comfort System; from which the Adaptive Thermal Comfort System is driven. Around it are the four categories that influence the thermal environment and are influenced by the adaptive system or the thermal environment (except for the weather which is an autonomous process). The new part is to make the building characteristics of solar gain, (natural) ventilation and insulation adaptive to minimise
the demand for (thermal) energy. This is done by controls driven by the adaptive system. This requires information of the occupant and that can be obtained by an advanced interface with feedback to the user and the possibility to overrule the systems decision. Furthermore, the HVAC system and the settings of the building characteristics are mutually tuned to optimally profit from all energy saving measures.
§ 1.2.1
Background hypotheses
Based on the previous section, the following hypotheses can be produced on which the research of this thesis is based:
–
Providing comfort only when and where and at the level needed will lead to significant energy saving compared to the current approach of delivering a predefined level of comfort based on averages of weather and occupant.–
Providing this comfort with an Adaptive Thermal Comfort System can significantly improve the energy efficiency of the dwelling.–
This Adaptive Thermal Comfort System does not compromise the comfort experience of the occupant.§ 1.2.2
Problem definition
In order to be able to create an Adaptive Thermal Comfort System to improve energy efficiency knowledge should be acquired as to where, when, what kind and how much energy is needed to provide the thermal comfort. Therefore research should be done to gain more insight in the dynamic behaviour of the weather and the occupant to be combined with opportunities to adapt the thermal comfort system accordingly to save energy.
§ 1.2.3
Research objective
The aim of the research presented in this thesis is to design adaptive concepts of an Adaptive Thermal Comfort System for Dwellings to achieve a significantly better energy performance whilst not compromising the thermal comfort perception of the occupants. The adaptive concepts are meant to activate the future development of adaptive techniques beyond the nowadays available as well as stimulate improved application of existing techniques.
To do so, three steps will be taken, which also represent the three parts of the research:
1 Gathering information about the dynamics of the factors that influence the thermal
heat balance of the dwelling and determine their opportunities for adaptivity. This requires a multi-disciplinary approach to Thermal Comfort Systems.
2 Researching the effect of applying the adaptive opportunities on the energy saving and
comfort delivery of the Thermal Comfort Systems to determine the optimal generic and individual physical characteristics of an Adaptive Thermal Comfort System for dwellings.
3 Providing design guidelines for product development and the design of a dwelling with
an Adaptive Thermal Comfort System and assessing some practical implementations.
§ 1.2.4
Methodology
The methodology of this thesis is based on the categorisation of the aspects influencing the level of thermal comfort demand and supply divided into the 6 domains used in this thesis, shown in Table 1.1. These 6 domains can be grouped into the external variables (the variables that are the driving force for supply and demand of energy) and the actual components of the Adaptive Thermal Comfort System.
The external variables are the occupant which poses the demand on the Adaptive Thermal Comfort System and the weather which delivers the (energy) supply for the thermal environment
The next domains form the actual Adaptive Thermal Comfort System and this can be subdivided into a passive part which only need auxiliary energy to influence the thermal environment and an active part which uses energy to regulate the thermal environment. The passive system consists of the spatial layout or the organisation and shape of the rooms in the design and the materialisation part which sets the filter characteristics e.g. the permeability of the shell for heat air and solar radiation. The active parts of the system are the HVAC system which actively applies energy to tune the thermal environment like heating and cooling and it can discard energy by mechanical ventilation and the control system to tune the whole system in accordance with the demand and supply.
type design phase chapter research type oc cu pa nc y
external variable brief 2 literature
w
ea
th
er
external variable brief 2 literature
la
yo
ut precondition preliminary design 3 literature
3 literature PART 2 calculations PART 3 integration 3 literature PART 2 calculations PART 3 integration co nt ro ls
control installationsmechanical 3 literature
H
VA
C
active ATCS installationsmechanical domain m at er ia l
passive ATCS materialization
TABLE 1.1 Domains of research in this thesis with reference to the research chapters
§ 1.3
Research questions
Resulting from the research objective and methodology the main research question is the following;
MAIN What are the most efficient strategies for delivering thermal comfort in the residential sector with respect to better energy performances and an increasing demand for flexibility in use and comfort conditions?
To answer this main question the following sub questions will each be researched and answered in a chapter creating the outline of the thesis (Figure 1.2).