TERCERA PARTE LA CONSOLIDACION DOCTRINARIA DEL EJÉRCITO COLOMBIANODURANTE EL GOBIERNO DE GUILLERMO LEÓN
CAPITULO QUINTO UN ACERCAMIENTO A LA VIOLENCIA DESDE LA DOCTRINA MILITAR DEL EJÉRCITO COLOMBIANO DURANTE EL GOBIERNO DE GUILLERMO
Technical building retrofitting and change of occupant behaviour make up the core con- cept of residential energy conservation in this doctoral research. The profile of residential energy consumption can be simplified described with Equation 2-1 below, which interprets the influencing components when calculating the actual household energy demand,
Eac.(x) = Eth.(x) • {ηi, δi, ζi} (2-1)
where
Eac.. : actual residential building energy consumption. [kWh/yr]
Eth. : theoretical energy demand for residential building, which is determined
based on the design standards of residential indoor environment and energy-re-
lated floor area. [kWh/yr]
ηi : thermal characteristics of building components, which shall take the dis-
count of thermal performance due to disrepair. ηi is allowed to be a weighted value
because it refers to different construction components with various thermal char- acteristics (e.g., thermal transfer coefficient U-value, thermal resistance value R- value, Solar Reflectance Index5 etc.). In addition, the impact of building orienta-
tion shall not be ignored.
δi: efficiency factor of energy equipment and appliances, such as HVAC (in-
cluding heating system, boiler, thermostat, ventilation and air conditioning), water heater, lighting and domestic electrical appliances. δi influences the internal heat
gain during using the household appliances and lighting.
ζi: energy-related behavioural elements of occupants, which influence the
household energy consumption and indoor air quality. This is a subjective factor with high random nature resulted from the social background of occupants and the social environment they living in. ζi influences the internal heat gain from occu-
pants owing to occupancy rate and energy-related indoor activities.
i: refers to different involved influencing elements (i.e. external and internal), which are introduced as energy efficiency indicators and applied as parameters for technical and behaviour-based energy consuming simulation in this dissertation. x: investigated residential building case.
In addition, climatic factors (e.g., heating degree days HDD/cooling degree days HDD) and other possible influencing factors, such as floor areas for heating, energy prices, res- idential energy policies and regulation, availability of renewable energy in residential sector etc.
Residential building energy efficiency improvement is implemented under both restrict conditions: one is design norms and standards for building energy efficiency retrofitting, another is a compromise among various stakeholders‘ requirements on costs and benefits. In Germany, norms and standards of thermal design are accepted for the framework of calculation and simulation towards determining the primary energy requirement of the residential unit in both annual and monthly balance sheets. The basic building energy efficiency standards applied in this doctoral research principally involve the thermal per- formance of residential buildings, as the final energy consumption for space heating in German households accounted for about 70 per cent of the total according to statistics from BMWi in May 2017. DIN6 V 41087 and DIN V 185998 as the main design standards for German building thermal performance and other domestic energy demand assessment.
6 DIN: German Institute for Standardization (Deutsches Institut für Normung e.V.), is the German na-
tional organisation for standardization and is the German ISOn member body.
7 DIN V 4108: Wärmeschutz und Energie-Einsparung in Gebäude (in English: Thermal protection and
energy economy in buildings)
8 DIN V 18599: Energetische Bewertung von Gebäuden - Berechnung des Nutz-, End- und Primärener-
giebedarfs für Heizung, Kühlung, Lüftung, Trinkwarmwasser und Beleuchtung (in English: Energy ef- ficiency of buildings – Calculation of the net, final and primary energy demand for heating, cooling, ventilation, domestic hot water and lighting)
The part six of DIN 4108 (i.e. DIN V 4108-69) provides the calculation concept of heating energy demand in buildings with Equation 2-2. A sum of the annual heating demand Qh,
the annual heat demand for domestic hot water Qw, and the heat losses of the heating and
hot water heating system Qt, taking the account of energy input Qr generated by energy
supply system (DIN V 4108-6, 2003, pp.12-14),
Q = Qh + Qw + Qt - Qr (2-2)
where
Q: total annual heat demand of buildings, [kWh/a] Qh: annual heating energy demand, calculated with the simplified procedure,
[kWh/a] Qh = 66 · (HT + HV) – 0.95 · (QS + Qi) (2-3)
HT: specific transmittance heat loss through building elements, such as
walls, windows, doors, floors and others. It depends mainly on three indices: the overall heat transfer coefficient, i.e. U-value [W/(m2K)], area of exposed surface A [m2] and temperature differ- ence ti-0 [°C] between internal and external surface. The relative
specific heat transfer coefficient due to ventilation allows being de- termined in accordance with DIN EN ISO 1378910, §4,
[W/K]
HV: specific heat loss caused by ventilation. It is determined by differ-
ent parameters, such as specific heat capacity of air cp [kJ/(kg·K)],
the density of air ρ [kg/m3], air volume flow qv [m3/s], and temper-
ature difference ti-0 [°C] between inside air and outside air. The rel-
ative specific heat transfer coefficient due to ventilation allows be- ing determined in accordance with DIN EN ISO 13789, §5,
[W/K] 66: HDD-factor, FGt, which results from the number of heating degree
days (≈ 185 days11, the number of days when the difference be-
tween outdoor and heating temperature is below 10°C) multiplied
9 DIN V 4108-6 (June 2003): Thermal protection and energy economy in buildings - Part 6: Calculation
of annual heat and annual energy use.
10 DIN EN ISO 13789 (April 2008): Thermal performance of buildings – Transmission and ventilation
heat transfer coefficients-Calculation method (ISO 13789:2007).
by conversion factors (= 0.024, from day to hours and watts to kil- owatts) and a reduction factor (= 0.95, which is a reduction factor for night setback of heating system). This value is used in heating- period method, which is identified in EnEV § 3 Abs. 2 Nr. 1 and Annex 1 Nr.3.
0.95: flat-rate utilization factor of heat gains,
QS: solar heat gains due to direct solar radiation through transparent
components of buildings, such as windows. It is determined by the orientation and size of the windows, the degree of energy transmis- sion of the glasses as well as the effects of the shading and the soil- ing of the panes12. It is determined by the total solar irradiations depending on building orientation, the total energy transmittance (particularly for vertical irradiation) determined by technical prod- uct specifications or according to DIN EN 410: 2011-0413, and the area of windows with the orientation Ai [m2], [kWh/a]
Qi: internal heat gains, which consist of the waste heat from people
living in and the energy-related equipment, for example, lighting, home appliances in kitchen and other living space. Equation 2-4 formulates the calculation for it (Staniszewski and Gierga 2016,
p.8), [kWh/a]
Qi = qi · AN · 24/1000 · t (2-4)
where,
qi = 5 W/m2 for residential building [W/m2]
AN = effective energy-related floor areas [m2]
t = days of the heating period per year [-] which is allowed to be simplified, as Equation 2-5:
Qi = 22 · AN [kWh/a] (2-5)
12 https://www.baunetzwissen.de/glossar/s/solarer-waermegewinn-1074411
13 DIN EN 410 (April 2011): Glass in building - Determination of luminous and solar characteristics of
where,
the factor 22 as a flat-rate value is calculated with the following background: it is assumed that the internal heat gain of residential buildings is 5 W/m2 and a heating period per year accounts for 185 days, therefore the factor results from,
5 [W/m2] · 185 [d] · 0.024 [kWh] = 22.2 ≈ 22
About effective energy-related floor area AN [m2], it is determined
by heated building volume Ve, as Equation 2-6 shown,
AN = Ve · 0.32/[m] (2-6)
where,
Ve [m3] is the heated building volume, which is the volume en-
closed by the heat transferring surrounded area A and determined through A multiplies ceiling height hg [m],
Ve = A · hg (2-7)
A is determined in accordance with Annex B of DIN EN 13789, i.e. the peripheral area,
and then
AN = A · hg · 0.32/[m] (2-8)
with 2,5 m ≤ hg ≤ 3.0 m, for a residential dwelling unit in general.
However, if hg ≤ 2.5 m or hg ≥ 3,0 m, according to Annext 1 Nr.
1.3.3 sentence 2 of EnEV 2013 AN shall be14,
AN = (1/hg – 0.04[m-1]) · Ve (2-9)
Qw annual heat demand for water heating, which depends on several parame-
ters, e.g., volume-specific heat capacity of water (ρc)w = 1.161
kWh/(m3·K), volume of warm water during the calculation period Vw [m3],
14 http://www.enev-online.com/enev_2014_praxisdialog/140811_19.04_dibt_ermittlung_gebaeudenutz-
the temperature-difference θw-0 [K] between the consuming-targeted dis-
charged hot water and the water before entry into hot water system. This amount can be determined according to DIN EN 83215, [kWh/a] Qt heat loss of energy-related equipment for heating and DHW supply in a
building, except energy loss during distribution, storage and generation, [kWh/a]
Qr: energy input to the heating system from regenerative source by additional
equipment, excluding the amount of energy directly from solar heat gains and heat-recovery from ventilation systems, which is included in annual heating energy demand Qh in general. Calculation of Qr refers to DIN
4701-1016. [kWh/a]
The equation above describes energy balance in residential building unit that can be de- picted in Fig. 2.1, which visualizes the general residential energy flow that is consumed, gained and wasted.
Figure 2.1 Energetically characteristic values of residential building/housing
15 DIN EN 832: Thermal performance of building - Calculation of energy use for heating-Residential
buildings.
16 DIN EN 4701-10 (August 2003): Energy efficiency of heating and ventilation systems in buildings -
A compromised solution for optimization of energy efficiency in residential buildings is inevitable owing to the conflicting interests (Shao 2015) and fragmented expertise (Yudelson 2010), but a rational compromise is also effective for the implementation of energy saving measures, which can address all involved stakeholders‘ requirements, evoke their attention and create their awareness under limited costs, as far as possible. Miller and Buy (2008) indicated in their study on the commercial building that energy retrofitting measures could not be successfully implemented without a full and effective participation and cooperation among stakeholders. However, focusing on the operational energy of buildings, the „mutual influence or interdependence“ among stakeholders re- lated to energy consumption in residential buildings is more complex than that in com- mercial buildings. It is reflected especially through the diversity of occupancy rate and occupants interaction with energy-related building components and equipment.
Based on the collected data about residential building energy consumption and the be- havioural features of occupants, this doctoral research is to analyse and verify the indoor thermal comfort and to stretch forward optimized energy performance (i.e. reduced en- ergy consumption, improved indoor air quality and living satisfaction etc.) through ad- justing the occupants’ schedules on occupancy and other energy-related indoor activities. This is an iterative process with simulation modelling. A subsequent discussion on simu- lation results is conducted towards the following key questions that attempt to be clarified in this research and need further study for more comprehensive solutions:
- The critical stakeholders related to the energy efficiency of residential buildings, their functions and constraints for reducing energy consumption.
- The nature of residential energy problem during the operation phase is arguably a problem between energy facilities and occupants, i.e. the interaction between the both. Therefore, an integrated assessment concept for energy efficiency in resi- dential buildings is developed to put the occupant behaviour as an important pa- rameter into any technological retrofitting solution, which thus takes the require- ments of critical stakeholders into account for striving for high participation and successful implementation.
- Suitable energy saving measures in residential buildings are labelled with tech- nical feasibility, economical affordability, as well as reliability and acceptability by occupants. Traditional cost-benefit-analysis is not enough to reflect the satis- faction of occupants, which influences the implementation of energy saving measures in turn. Therefore, with the simulation tool a satisfaction rate of occu- pants on their indoor environmental quality can be calculated, which depends on a range of factors, e.g., performance of energy equipment, energy-consuming be- haviour, energy prices, and weather etc.
aiming to delve into the influencing factors and specify the framework of energy efficiency optimization in residential buildings concerning consumption and sav- ings, environmental impact and indoor environmental quality.
An efficient energy performance in residential buildings can be achieved in a sustainable way, in the event that the energy saving measures are developed with a full consideration of stakeholders‘ features (e.g., interests, obligations, requirements, and limits), as illus- trated in Fig. 2.2. The research model in this dissertation is established with energy- related information based on limited data from research projects on social housing energy efficiency in Germany, therefore, owing to data protection there is some assumption for modelling and will be indicated for the following simulation.
Figure 2.2 Fundamental principle of sustainable energy performances of residen-
tial sector