Daylight analysis using Revit - with design suggestions

Revit House Optimization

Assignment 2:

Building information management

SID: 480407278

Project brief:

Renovation proposal for Revit house client.

Concern: 1. Overheating of lower level living room in summer 2. Too much direct sun in the room

Focus of the design proposal:

The following proposal has been prepared as a result of various vertical and horizontal shading systems. There is a focus on employing a shading device which is easy and fast to install with minimal disruption to the client at home. At the same time are flexible and customizable to the changing needs of the user.

The most efficient design for a residence, in our experience, gives operable control to the user – so this design proposal is adaptable to the erratic Sydney weather.

We will keep our focus on the months of December and January for the hottest months of the year. The robustness of the proposal will be checked for winter suitability to make sure it doesn’t reduce the solar heat gain in winters too much.

1. Sun Path study on the site Summer solstice: 21 December at 10 am the solar radiation is high, and the sun penetrates deep into the living space

21 January at 10 am the solar radiation is high, and the sun penetrates deeper than Dec. into the living space

21 February at 10 am the solar radiation is lower than December or January but still hot, and the sun penetrates deepest of the three months into the living space

Winter Solstice: 21 June at 10am the solar radiation starts getting high while the sun is low in the sky, penetrating very deep at a low angle

21 January at 8am the sun starts entering the room from the ESE direction at a very low angle. After 1pm there is no direct sun in the living room.

Design development: The solar study indicated two main solutions: 1.

Horizontal shading is required on the north façade and to some extent on the east façade as well.

2.

The length of shading needs to be carefully designed as to not cut out the winter sun. climate consultant is used for determining the appropriate length to block the summer sun Angular vertical shading on the east to block the low angle sun In summer mornings in the ESE part of the hemisphere Vertical shading would be angled to reduce the morning direct sun glare in summer but not the winter early morning sun

Design strategy: • Give the occupant control of how much daylight do they want in the space depending on time of the day, activity, and weather.

• Fixed shading is focused on reducing the solar heat gain in the space and will help reduce the heat gain even when the occupant does not want to intervene with the operable shading device.

• The summer heat gain of the house also depends on the material selection. For this, the glazing has been changed to a high performing double glazing with a low e-coating from the single glazing • The roof needs more insulation as the current roofing is only RCC. Insulation is added to the roof slab and finished with a light colour finish to increase reflectivity and hence reduce the solar gain.

Needs more insulation

Needs better performance glass

Requires vertical shading

Requires Horizontal shading

Area of focus

Design proposal

Roof with insulation and reflective finish: New buildup Source: Author (Revit 2020)

Curtain wall double glazing: New buildup

Source: Author (Revit 2020)

Double glazing buildup with argon air in between. Section.

Source: Author (Revit 2020)

Significant U –value increase in high performance glass

(Source: Author) (Window 7 Software) External insulation and reflective Double glazing e coating glass shading added to roof

Fixed horizontal shading

Fixed vertical shading reducing solar gain Operable vertical shading device

External seating for sunny winter days

Fixed horizontal shading

Interior views December 21 Original

Updated

8am : Summer Morning

12pm : Summer afternoon Remarks: Reduction in direct sun entering the living space during early morning. Complete cutoff of direct solar gain from 12pm when the solar radiation is very high

Interior views January 21 Original

Updated

8am : Summer Morning

12pm : Summer afternoon Remarks: Reduction in direct sun entering the living space during early morning. Complete cutoff of direct solar gain from 12pm when the solar radiation is very high

Interior views June 21 Original

Updated

8am : Winter Morning

12pm : Winter afternoon Remarks: daylight quality is improved by reducing direct solar gain, but it is maintained that solar gain is not reduced too much.

Lux values December 21 8am: Summer morning

10am Original

Updated

12pm: Summer afternoon

Lux values January 21 8am: Summer morning

10am Original

Updated

12pm: Summer afternoon

Lux values June 21 8am: Winter morning

10am Original

Updated

12pm: Winter afternoon

Findings and conclusion Using a fin system with spacing between two fins, attempts at maintaining the views from the human eye level. By flushing the shading device close to the wall, shading is found to be more effective and the view is minimally affected.

LUX value is used as a matrix for benchmarking the progress. This made sure that daylight levels were not compromised. The more uniform a lux value map is, the better is daylight quality in the space (uniformity ratio) In conclusion, by using solar study and material research, the envelope in improved for the thermal and visual comfort of the client. Improvement in daylight quality is observed during summer as well as winter months. Solar heat gain is optimized by use of high-performance glazing and better insulated roof envelope.

Modeling methodology and appendix Creating double glazing: To create a double-glazing profile, a generic wall system is duplicated and modified.

The structure has 3 layers, glass on the external layers and air space in the middle.

This directory is applied to the curtain panel system for curtain wall system.

Creating louver shading device: These shading device are essentially curtain walls with empty panes. The mullion profiles are duplicated and modified to try different design ideas.

LUX value calculation: The lux values are calculated for a Perez all weather sky model which doesn’t necessarily use the average data for a certain date and time for the location but uses the data best suited for that instance.

Perez All-Weather Sky Model (2020) Shading size and angle: The appropriate latitude angle to be blocked by the shading was determined by using climate consultant’s sun shading chart. The aim is to use the smallest shading possible at the best location. A 60˚ angle was found to be appropriate. Therefore, a 1200mm wide horizontal shading at 2500mm height was the first shading tested. After these vertical shading is applied as required.

References 1.

2.

3.

Perez All-Weather Sky Model (2020) Available at: https://docs.agi32.com/AGi32/Content/references/Perez_All-Weather_Sky_Model.htm (Accessed: 4 June 2020).

Milne, M. and Liggett, R. (1976). Climate consultant. California, US: UCLA energy design tools group.

2020. Revit. Autodesk inc.