Cove.tool automates the process for a full floor daylight study and runs highly complex Revit, Sketchup, Rhino/Grasshopper models in a few minutes (as compared to a few hours that it takes other platforms).
What is sDA?
Spatial Daylight Autonomy (sDA) describes the percent of space which receives sufficient daylight. This analysis type is not a lenient metric as the exact definition defines all the required parameters in order to determine the building's daylight performance. To elaborate, sDA (Spatial Daylight Autonomy) describes the percentage of floor area that receives at least 300 lux for at least 50% of the annual occupied hours (8am-6pm) on the horizontal work plane (30" above floor).
What is ASE?
Annual Solar Exposure (ASE) refers to the percentage of space that receives too much direct sunlight (1000 Lux or more for at least 250 occupied hours per year), which can cause glare or increased cooling loads.
I uploaded Geometry before Nov 1st. Why do I need to re-upload?
There are new data categories we need to run the daylight simulation that are only done by the latest Revit plug-in. We're working on updating the Sketch-up and Rhino plugins and expect to have them ready in November, as well.
Why do early stage daylight modeling?
Early stage daylight modeling allows our users to quickly understand the impact of various design decision on the spatial daylight autonomy of the space. Research highlights the benefit of daylight in health, happiness and productivity.
What is our Calculation Method? Taken from "LEED v4.0 - IEQ c7 Daylight, Option 1. Simulations: Spatial Daylight Autonomy" and "IES LM-83: Approved Method: IES Spatial Daylight Autonomy (sDA%) and Annual Sunlight Exposure (ASE)" Cove.tool runs a full ray-tracing simulation and is calibrated to within 1% to 5% of a DIVA Radiance simulation. The 500x speed improvement comes from employing new statistical methods, machine learning, and parallelizing the calculations on our back-end server environment. We are using a Tregenza sky with 145 subdivisions. To speed up the simulation we are keeping the reflectivity fixed for now with the following assumptions: Floors 40%, Interior Walls 70%, Ceiling 70%, Exterior Facade 35%, and Walls 35%. This allows any user to construct a realistic simulation and avoids "cheating" the simulation with incorrect inputs.
How does it set up the model?
In a daylight model, there are a few factors that are key to determining the impact of daylight on your building including:
1. Location: The sky dome, which represents the amount of light those emanating from the sun, the sky and clouds, is auto created and loaded for any location on Earth. In cove.tool this is done automatically for you.
2. Geometry: cove.tool pulls in the Geometry directly from your 3D model using the cove.tool plugins for Revit, Rhino/Grasshopper and Sketchup. The geometry is pulled out in various layers for glass surface, wall surfaces, floor surfaces, roof surfaces, shading structures (which can includes the overhang/fins/light shelves, but also context and buildings). To represent trees upload boxes instead of complex foliage. The geometry is then accurately represented within the cove.tool web-app.
3. Grid Size: The grid size as a measurement unit in ft/m represents the size of the analysis grid on which the simulation is done. The smaller the grid size, the slower the simulation. The cove.tool model, auto runs at a 6 ft grid but can be modified by the user down to 2 ft for a LEED level daylight grid.
4. Visual Transmittance (VT%): Visible transmittance is the amount of light in the visible spectrum that passes through a glazing material. Using the Visible Transmittance (VT%) slider, users can control the amount of daylight which passes through their windows. A higher VT% means more daylight penetrates the interior space which, can directly impact electric lighting and its associated cooling loads. NOTE: SHGC and U-Value for Glazing materials can be changed on the Baseline Energy Page.
5. Rotation Angle (°): Users can use this input to rotate their daylight model. Notice that the blue vector on the daylight grid indicates the North direction, and by entering a rotation angle will re-orient their project x-degrees clockwise from North. This input will be useful for a user who has Site North differing from the BIM Project North, or in the case of a orientation/massing study.
Can I submit this for LEED compliance?
Not yet! But soon! We need to give users a way to denote unoccupied areas. We're working on this feature for mid 2020.
Which direction is North?
The blue axis indicates the North direction.
How do I navigate in the Daylight Page? Orbit, Zooming, Panning?
Best tips are to use a mouse to click and drag to pan around the 3D space. Holding down the Shift key, then using the mouse to drag will also help quickly travel across the daylight grid with more precision. Last using the Set Views button for Top and 3D, will help get users to the best views for generating reports.