Conservation Consultants, Inc. has been a strong advocate of energy conservation education for nearly 30 years. Its downtown Pittsburgh office, formerly an old vacant building, has become a green showcase with solar panels, state-of-the-art lighting, and efficient energy usage. Each year, hundreds of school children tour the CCI Center to learn the benefits of smart energy. One of CCI’s most recent green projects was the installation of a green roof atop its office building.
A green roof is partially or completely covered with vegetation and soil, or another growing medium, planted over a waterproof membrane. The popularity of green roofs continues to grow as organizations realize the benefits of implementation. These benefits are ecological, economic, aesthetic, and psychological in nature.
The Green Roof was part of 28 innovative green projects throughout Pennsylvania funded by a state Department of Environmental Protection grant. Melanie Tuck, a green roof consultant, spent 15 months planning and designing the project. Part of Tuck’s system design was to include a highly accurate, low-maintenance green roof monitoring system. NexSens Technology was contacted to help provide this monitoring solution.
The right system for the job
The CCI green roof features a four-inch layer of vegetation, a public walkway built of recycled pavers, solar panels between the skylights for a solar-powered hot water system, a rain barrel to capture stormwater runoff from the third-floor roof for irrigation use, and real-time monitoring equipment with a computer kiosk for the public to view the benefits of green roof implementation.
The NexSens green roof monitoring system consists of a Vaisala WXT-series multi-parameter weather sensor, NexSens AccuStage water level sensor, and Stevens Hydra Probe II Soil Moisture Sensor, which can also calculate salinity and temperature. The WXT520 weather sensor simultaneously measures wind speed and direction, liquid precipitation, air temperature, relative humidity, and barometric pressure.
Each sensor is strategically placed on the roof to help quantify the reduced amount of stormwater runoff from the green roof implementation. The weather sensor measures the amount of precipitation falling. Soil moisture sensors provide an indication of the amount of rainfall being absorbed by the soil. Finally, the water level sensor is used to quantify the amount of water running into the roof drain. According to the Environmental Protection Agency, three to five inches of soil can absorb as much as 75% of rain events that are half an inch or less.
Data from the green roof monitoring sensors is collected and processed by a NexSens iSIC data logger connected to the nearby computer kiosk. At the computer, both iChart software and WQData are used to view current data and analyze historical data — all on a graphical, user-friendly interface.
The NexSens X2 Environmental Data Logger offers the latest in real-time monitoring technology with wireless communication, large plug-and-play sensor library, and ultra-low power consumption.
Designed to resist the elements, the Seametrics PT12 delivers accurate pressure and temperature readings in rugged environments.
The Vaisala WXT536 Multi-Parameter Weather Sensor simultaneously measures air temperature, humidity, pressure, rainfall and wind in a compact platform with optional heating.
The Stevens Hydra soil moisture sensor provides simultaneous measurement of soil moisture, salinity, and temperature using a unique patented design.
WQData LIVE is a web-based project management service that allows users 24/7 instant access to data collected from remote telemetry systems.