1、;#23#23#23Author A is corresponding author and is a Industrial PhD at Department of Civil Engineering, Technical University of Denmark and has a M.Sc. in Architectural Engineering. Author B is a PhD at Department of Civil Engineering, Technical University of Denmark and has a M.Sc. in Architectural
2、Engineering. Author C is a Industrial PhD at Department of Civil Engineering, Technical University of Denmark and has a M.Sc. in Architectural Engineering. Integrated Design - A paradigm for the design of low-energy office buildings M. JrgensenA, M. W. NielsenB, J. B. Strmann-AndersenC, Department o
3、f Civil Engineering Technical University of Denmark ABSTRACT This paper presents a case study of the implementation of integrated design in an actual architectural competition. The design process was carried out at a highly esteemed architectural office and attended by both engineers and architects
4、working towards mutual goals of architectural excellence, low-energy consumption, and high-quality indoor environment. We use this case study to investigate how technical knowledge about building performance can be integrated into the conceptual design stage. We have selected certain points during t
5、he design process that represented design challenges and describe the decision process. Specific attention is given to how the engineering input was presented and how it was able to facilitate the design development. Site and context, building shape, organization of functions and HVAC-systems were a
6、ll included to obtain a complete picture of the buildings performance. This article illustrates how a continuous implementation of technical knowledge early in the design process for an actual architectural competition resulted in a building design with an energy demand approximately 30% lower than
7、Danish building regulations, yet which still maintains a high quality of indoor environment and meets the demands of architectural excellence. INTRODUCTION It has been economically and technically possible to design and erect low-energy buildings both homes and offices for decades. But it is not oft
8、en done, and many new buildings are overly expensive and have high energy consumption. One important obstacle is the architectural process of designing buildings, in which scientific technical knowledge informs the architectural project too late (Clarke, J., 2001) #23#23#23Figure 1 Graph showing the
9、 buindicate the performanThe daylight availability and its arrangement of desks. This made it possand the required number of well-lit work35% Figure 2 Illustration of the dacoupled with floor plan35% Figure 3 Pictures of referenceEberle Architects). Output The energy and daylight simulatio0204060801
10、0035%Energy requirement kWh/m2per yearEnergy perfLow-energy ildings energy performance dependence on the faace requirements stated in the competition brief. distribution were simulated and coupled with drawible both to illustrate and constantly ensure that the spstations could be established. 50% 65
11、% ylight availability and distribution simulated for s. The red area indicates a daylight factor below 2%50% 65%projects with corresponding faade transparenciesns showed how an increased faade transparency r50% 65%Faade transparencyormance;#23#23#23Class II ;#23#23#23de transparency. The red lines i
12、ngs of office plans including atial demands could be fulfilled 80% various faade transparencies . 80% (Illustrations: Baumschlager-esulted in an increased energy 80%HeatingCoolingArt. LightingFansHot Water234 ASHRAE Transactionsdemand but at the same time provided higher illuminance levels as shown
13、in Table 1, which meant that a greater number of well-lit workstations could be established as a result of faade transparency. A balance between energy demand, indoor environment, and architectural intentions began to take form. A faade transparency of 50% was agreed upon, because it provided a suff
14、icient amount of well-lit floor area to meet the spatial requirements, while at the same time it ensured that the buildings total energy demand would meet the contractors wishes. DESIGN DECISION “ANGLING THE FAADE” Further architectural processing of the faade was carried out to refine the architect
15、ural expression and to optimize performance with respect to energy and the indoor environment. The architectural intention was to design a faade that would relate to the existing brick structures as required in the brief, but at the same time reflect the dynamics of the water present all around the
16、site. So the faade should be both solid and dynamic. The main parameters were: an architectural dynamic to the faade, better utilization of the views provided by the extraordinary location, and a significant reduction in the cooling demand. Collectively in the design team, the idea arose of faceting
17、 the faade, angling the opaque and transparent parts differently. In particular, angling the windows towards the north would not only optimize views toward the city and the entire Copenhagen bay area, but also significantly reduce insolation and thereby the cooling demand. Analysis Thermal and dayli
18、ght simulations were carried out for a section of the building with a faade transparency of 50% and window orientations ranging from 0 (east) to 45 (northeast). Default values were assigned to all variables except those that related to the orientation of the window. Table 4. Energy performance was s
19、imulated in accordance with the European Directive EPBD as defined in (EN 15251:2007). All energy demands are stated in kWh/m2per year (kBtu/ft2per year), and daylight factors were simulated for the third row of tables from the faade. Window orientationEnergy performance 0 (East) 15 30 45 (Northeast
20、) Heating 11 (3.5) 12 (3.8) 13 (4.1) 14 (4.4) Cooling 14 (4.4) 12 (3.8) 9 (2.9) 7 (2.2) Artificial lighting 19 (6.0) 19 (6.0) 19 (6.0) 19 (6.0) Fans 21 (6.7) 21 (6.7) 21 (6.7) 21 (6.7) Hot Water 5 (1.6) 5 (1.6) 5 (1.6) 5 (1.6) Total 70 (22.2) 69 (21.9) 67 (21.2) 66 (20.9) Daylight factor % 2.2 2.2 2
21、.2 2.2 Presentation Graphic illustrations were presented showing the positive effect and tendency in the cooling energy demand as the windows were increasingly angled towards the north. Simulations of daylight levels were coupled with office plans to ensure correlation between the spatial demands an
22、d the number of well-lit workstations. Furthermore, renderings of the daylight distribution in an east-facing office were generated for the various window orientations. Together, this formed the basis for an interdisciplinary discussion focused on spatial perception, possible floor plans and the eff
23、ect on the cooling demand. 2011 ASHRAE 235Figure 4 Graph showing the deEast and 45 to Northe0 (East) Figure 5 Illustration of the daylwith floor plans. The rFigure 6 Renderings of the daylOutput Multiple positive effects obtained architectural appearance. The cooling ddependence of the solar heat ga
24、in coeffiof the windows towards the north changthe weight of the masonry provided the the angling of the faade from 15 to 30the faade was chosen. DESIGN DECISION “OPTIMIZING TWith a fixed building width of 25 relatively large room depth. A distance resulted in a lot of floor area being unudouble roo
25、m height was seen as an oppthe flexibility of the floor area, but also t0510150g131Cooling requirementkWh/m2per yearpendence of the cooling demand on the window orieast. 15 30 ight availability and distribution simulated for varioued area indicates a daylight factor below 2%. ight distribution in an
26、 east-facing office for various faby angling the faade were presented with respect toemand was reduced, due to the combination of lecient, resulting in less heat from direct sun. At the saed the character and expression of the building, prosolid aspect. The greatest reduction in the cooling de, and
27、since no major deterioration in daylight levels HE PLACEMENT OF THE STRUCTURAL CORmetres (82.0 feet), another important design challengof approximately 10 meters (32.8 feet) from the faasable for workstations due to insufficient daylight. ortunity not only to increase daylight levels in the ceo gene
28、rate a more inspiring spatial feel. 15g131 30g131Window orientationntation. 0 corresponds to due 45 (Northeast) s window orientations coupled ade angles both energy performance and ess sun exposure and the angle me time, staggering the angling viding a dynamic aspect, while mand was found by increas
29、ing was registered, a 30 angling of E” e was optimal utilization of the de to the centrally placed core The introduction of areas with ntre of the building, increasing 45g131236 ASHRAE TransactionsAnalysis Thermal and daylight simulations towards the east and the asymmetrically Table 5. Energy perfo
30、rmandefined in EN15215:2007. AEnergy performance Heating Cooling Artificial lighting Fans Hot Water Total Presentation Daylight simulations were coupledrequired in the competition brief and thand comparing it to the point of departurFigure 7 Illustration of the dayldouble-height space isthe actual f
31、loor plan. TOutput Results showed an improvement workstations. The floor area where daylsuch as infrastructure, meeting rooms, reduced, the spatial requirements could swere carried out for a characteristic section of the buplaced core towards the west. Default values were assce was simulated in acco
32、rdance with the Euroll energy demands are stated in kWh/m2per Different room heightSingle Height 13 (4.1) 9 (2.9) 19 (6.0) 21 (6.7) 5 (1.6) 67 (21.2) with updated office plans to ensure correlation betwe daylight availability. By illustrating the potential efe, it was easy for the design team to sel
33、ect and adapt tight availability and distribution simulated for a typioriented towards the east. The simulation is coupledhe red area indicates a daylight factor below 2%. in daylight availability and consequently the optiight levels were insufficient correlate with the area ntoilets, etc. The desig
34、n presented showed that, althtill be fulfilled by using the remaining area in a more ilding with double room height igned to all variables. pean Directive EPBD as year (kBtu/ft2per year). Double Room Height 17.5 (5.5) 4.5 (1.4) 26.3 (88.3) 11 (3.5) 5.4 (1.7) 64.7 (20.5) een the number of workstation
35、s fect of the double height room he design to results. cal section of the building. The with architectural drawings of on of a better distribution of eeded for secondary functions, ough the floor area had been effective manner. 2011 ASHRAE 237Figure 8 Renderings of the double room height and the cha
36、racteristic faade (Illustrations: Henning Larsen Architects A/S). DISCUSSION The first step in improving the energy performance of a building is taken with the architects first sketch on paper. It is here that the framework and preconditions for the performance of the building will be set. Quantitat
37、ive and qualitative technical input from the beginning of the design process increases the awareness and recognition of the correlation between the buildings design (transparency, orientation, functional organization, etc.) and its energy demand. This reduces the risk of having to introduce technica
38、l solutions later in the process to compensate for fundamentally bad design choices at the beginning. Uninformed decisions early in the process can limit the potential for energy savings. The integrated design process requires an interdisciplinary collaboration between engineers and architects. A tr
39、aditional engineer is trained to work rationally and linearly, while an architect works iteratively with multiple potential solutions at the same time. Problems with communication and collaboration often occur in the early design process, because the engineer is not accustomed to dealing with a vari
40、ety of solutions, while the architect perceives the engineer as a problem-solver and not a creative collaborator. Engineers need to be better at actively communicating and illustrate their technical input and be capable of contributing with multiple parameter solutions that can challenge and inform
41、the architects design. CONCLUSION The case study presented shows how technical input can facilitate design development if the focus is on translating results into an architecturally oriented presentation. A visual representation of energy and daylight simulations, coupled with spatial considerations
42、, can form a very strong part of the design argument and enrich the reasoning behind design decisions. The architectural engineering background of the engineers involved was seen to have enhanced the collaboration significantly due to a training involving architectural as well as classical engineeri
43、ng skills. A key aspect is being able to understand architectural concepts and translate them into performance parameters and possibilities while at the same time identifying the architectural and spatial potential in the technical results. The conceptual design proposal presented in this case study
44、 was a contribution carried out at Henning Larsen Architects A/S for an actual architectural competition. With the fusion of architectural considerations and technical knowledge, the design team produced a proposal that completed the line of existing warehouses and made full use of the views from th
45、e unique location with a more modern architectural expression. By angling the faades towards the north, it was possible to maintain a certain degree of openness towards the surroundings, improving daylight conditions while reducing the energy demand for cooling. By using passive and integrated desig
46、n solutions coupled with simulations of energy and daylight, we achieved a building with architectural excellence that met the requirements for thermal indoor environment and air quality corresponding to Class II as described in the European Standard (EN 15251:2007) and had a low-energy demand of 64
47、.7 kWh/m2/year (20.5 kBtu/ft2per year) well below the requirements stated in the competition brief. 238 ASHRAE TransactionsACKNOWLEDGMENTS The authors wish to thank Henning Larsen Architects A/S and the external collaborators for their support and the opportunity to be part of the design process. RE
48、FERENCES Clarke, J., 2001. “Energy simulation in building design”, second edition. Butterworth-Heinemann. Crawley D.B., Hand J.W., Kummert M., Griffith B.T., 2008. “Contrasting the capabilities of building energy performance simulation programs”. Building and Environment, vol. 43, 661-673. Danish Bu
49、ilding Regulations, 2006. “Bygningsreglement for erhvervs- og etagebyggeri”, National Agency for Enterprise and Construction, Copenhagen. DS/EN 15251:2007. “Indoor environmental input parameters for design and assessment of energy performance of buildings addressing indoor air quality, thermal environment, lighting and acoustics”, 2007. G.W. Larson, R. Shakespeare, 1998. “Rendering with Radiance”, Morgan Kaufmann. Intelligent Energy, 2006. “Mapping of previous integrated energy approaches”, Part of work package no. 2 in the EU INTE
