Prediction
2014
TOPICS: A- Prediction Temperature and Humidity, B- Prediction of sunlight/ daylight and artificial light , C- Prediction of Sound Level (Ecotect View),
1- Introduction:
Autodesk Ecotect Analysis is an environmental analysis tool that enables to simulate the building performance before preparation of conceptual design. (6) Ecotect Analysis provides various types of simulation and building energy analysis across sustainable environments. Basically, the analysis consist of, whole building energy analysis, thermal performance, water usage and cost evaluation, solar radiation, daylighting, shadow and reflections. (7)
In this particular study, thermal, lighting and sound analysis of my room is examined by Autodesk Ecotect Analysis. At first, general methodology is written regarding to the beginning to the end of the study. Afterwards, thermal analysis is completed. The related graphs on thermal analysis are illustrated. The analysis of light and acoustic are followed respectively. At final stage, exporting of Ecotect file into other programs is examined.
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2-Methodology:
1- Before starting on Ecotect plan, climate of that specific area should be installed. In this study, climate of Dundee is installed.
2- Load the AutoCAD plan of flat in DXF. Format to Ecotect. While importing AutoCAD plan to Ecotect, make sure the measured units are both same in both programs. Because of this, the scale of AutoCAD file is arranged in millimetre unit. While importing the file, base units are taken into a file in millimetres too.
3- The Autodesk Model Setting for grid setting X, Y and Z should be entered regarding to the size of the flat.
4- To create the zones. It is a very significant design process for performing thermal analysis in Ecotect. (1) Separation of the flat by zones can be completed by separation of rooms. If there is no change in air flow, heat convection or no different purpose from that area, in this case, no need to create an additional zone.
5- The zones are arranged as the wall lines passing on the plan.
6- Next step is to draw windows and doors at the correct position as indicated in AutoCAD plan. In this study, every room has their own bathrooms. In fact, every bathroom could be counted as another zone, only my room is separated as bedroom zone and bathroom zone. Because the main examination will be accomplished for this room. As a result, all windows are drawn. All exit doors and my bathroom door is drawn as the projection of the plan. The virtual illustration can be seen as below Figure 1 and 2.
7- Before examining any analysis, the site specifics must be completed. Because, one of the effect of this arrangement will cause the change in the solar gain of specific area as well as thermal analysis result.
8- At first, thermal performance of the flat will be taken into consideration. From “Calculate” option, Thermal Analysis section will calculate the thermal comfort related equations automatically. We want to analyse only the specific room among other zones, for this reason all other zones as well as outside are turned off for thermal performance. (2) And, zone management section right below part will assist to determine our specific settings for
the room such as: internal design conditions and occupancy and operation.
9- After completion of thermal analysis, the light analysis can be examined in the same designed project. At first, the offset is arranged as 0.74 m. Because, previously the height of working height is measured as 0.74 which is the level of desk in the room.
10- The light analysis grid should be determined before analysis. Otherwise, the program will ask you to define specific point or grid.
11- Artificial lighting in room is placed as similar position to the room. And the lamps are selected as “Simple Light”
12- After completion of both natural and artificial lighting analysis, statistical reverberation will be checked.
13- Finally, the Ecotect file can be exported to other useful tools by export manager for following analysis.
Figure 7, the outside and “Zone 3” temperature is in the blue bands which means generally colder than comfort band. In a year, temperature changes between 0o C and 24oC. And 10 oC is the most regular temperature degree observed from outside For “Zone 3”, 10 oC and 16 oC are largely dominant degrees per year which together nearly makes four months in a certain degree. And, there are no mines degrees all throughout the year.
In addition, as expected the closest area to the window takes the most natural daylight intensity in the specified grid which is at maximum level close to the degree of 3000 lux. As can be seen in the Figure 11, the points where the solar intensity is at the maximum level reaches the top levels.
On the other hand, the points where the solar intensity receives low intensity of sunlight, positioned at minimum level.
3-Results and Findings:
A- Thermal Performance Analysis:
However, wall and window is selected as mentioned in methodology part, because of warning indication and below explanation is changed as Ecotect default. For accurate thermal calculations, however, you should avoid inappropriate cross assignments, such as assigning a WALL object a WINDOW material. This will not make the WALL into a WINDOW, it will simply generate a warning and mean that values for alternating solar gain are erroneously
used in place of thermal lag and decrement properties (5)
As shown in Figure 6, hourly temperature change and hourly gain of “zone 3” (my room) is calculated by Ecotect. The date is 24th of October that can be taken the beginning of the Hobo test experiment.
According to the hourly temperature graph, selected “zone 3” temperature is generally higher than the outside temperature. There are no additional heat gain affect to “zone 3” and the temperature remains steady throughout the day. However, as the “zone 3” line states in blue band which illustrates the zone is below its designated comfort range. (3)
As can be seen in Figure 6, heat loss is caused mostly by conduction. During the day, heat loss by conduction increases from morning to evening as well as ventilation. However, ventilation causes a slightly less effect on a daily gain and loss graph. And, the average 2 kW heat gain during the day, is because of mainly one person produces heat energy which is specified in zone management.
After day-light analysis, the artificial light analysis is performed. And, the test takes relatively long time compared to the thermal performance analysis.
As a result of this test, the average lux was received as 312.96 lux which is significantly
higher degree than monitored electricity lux which was in degree of average 110 lux.
The possible main reason of observation this particular difference between monitoring and prediction test in this relation can be explained by the different type of lamp and the angle of the lamp which were not known completely. And, the accuracy is very sensitive, which might affect the observed data significantly.
From the Figure 12, the lamp at corner side, above the bed (1600 – 1000 lux) creates a (colored by light-orange) peak which indicates the top level of light intensity, compared to the lamp above the desk (1000 – 500 lux ) creates medium light intensity respect to the lamp at ceiling. (Figure 12)
As can be seen in Figure 8, a solar incident can be reached maximum 480 Watt at the position of the building during the year. Most of the year, dark blue or near blue colour is dominant that causes heat loss substantially larger than heat gain.
During from May to September, between 8 am and 22 pm is possible to see the sun above the sky. And solar heat gain reaches to the maximum level in July, compared to December and January, it declines to the minimum level.
The maximum and minimum heat energy changes between 40 Watt and -40 Watt in Figure 9 (Internal-zonal heat gain during the year for Zone 3) that is substantially lower energy changes during the year in order to change used materials.
B- Lighting Analysis
Regarding to the Figure 10, the average daylight value is calculated as 575.90 lux. Previously, in the daylight monitoring test in the room, it was in average as calculated 664.23 lux.
However, the observed values presumably close to each other, the selected value is substantially related to the many factors for instance; sun position in the exact day and period of time.
C- Acoustic Analysis
Since the blue band indicates the comfort zone, the determined zone is as in Figure 13 mostly in the ideal zone.
View of Prediction Test of sunlight by Radiance
View of Monitoring Test of sunlight by tools
The view of room in 3D is examined in Radiance. The exported Ecotect file can be read by Radiance program and after convertion of the data, the below Figure 13 was created.This view of figure presented of inside the room on the date of 09.10.2013 at 16.00 pm. which was the time of sunlight monitoring inside the room experimented. And, the next figure presents the monitoring test for the same type of evaluation but from the point of view of the fact observation.
4- Conclusions:
Ecotect Analysis program is completely helpful program which provides holistic visual understanding, related calculations in many formats and detailed help menu. However, the program has embodied many building analysis as mentioned in the introduction part, in some cases other software programs such as Energy Plus, Radiance and HTB2 tool can offer more comprehensive information. In addition, Ecotect has another advantage is that give us an opportunity to export and analyse the project in another program from the last saved version. However, as practices in this study, while Ecotect is able to test thermal analyse, the other programs may not work in the same settings.
In conclusion, more practises on Ecotect program will certainly give a chance to understand both the program itself and the building behaviour in different conditions such as designed material, position of building towards sun and designed fabric. From this perspective, Ecotect Analysis is highly promising tool in order to achieve energy efficient and sustainable buildings.
5- References:
1- http://wiki.naturalfrequency.com/wiki/Layers_and_Zones
2- THERMAL PERFORMANCE – Introduction (2013), Loading the Thermal Model, Page 01
3- THERMAL PERFORMANCE – Introduction (2013), Calculating Internal Temperature, Page 04
4- THERMAL PERFORMANCE – Introduction (2013), Statistical Analysis, Page 07
5- http://wiki.naturalfrequency.com/wiki/Material_Assignments_Panel
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