By combining IES product photometry with typical meteorological year (TMY) data, the Solatube Design Calculator measures the distribution of light from a Solatube product based on actual weather at a specific project site. For design purposes, the calculator uses the standard CIE date of September 21st, however, any specific date can be used.

Product selection based on size and quantity can also be compared to ensure that designers maximise the working source of light for their project. The end result is data that can be supplied to the client, or council, showing that the project meets G7 requirements.

Specification Managers at Hometech can take the details from the project and provide designers with the following reports:

• System Summary: A single-page report showing the annual performance of a particular Solatube design solution. The plot represents the average weekly daylighting performance for each hour of the day throughout the year. Thus, designers can use this summary to determine if the solution achieves the minimum lighting level for that particular project.
• Hourly CSV File
• IES File
• Create Point by Point
• Candela Plot Illustration

Kim Reed, Specification Manager for Hometech recently used the Design Calculator for a group home building company so they could submit data to council illustrating that a bedroom (3.5m x 4.0m) with a small window could meet standards by installing a Solatube 290DS. By installing the 290DS they exceeded the minimum 30 Lux with an average of 112 Lux (max. was 160, min. was 81).