Demonstration and Data Gathering Tutorial

This document sets out the methodology for data collection as part of the Million Cool Roof Challenge. If you have any questions regarding the minimum requirements please contact team@coolroofschallenge.org.


What is to be measured

  • External free stream air temperature. Measure at a height above the roof surface which is not obstructed by any objects. Measurements  must be done at the middle of the roof surface not in corners.

  • External roof surface temperature. Measurements must be done at the middle of the roof surface not in corners. Thermocouple much be taped and painted with same cool coated paint. Must not be in area which remains in a shade.

  • Inside air temperature using Globe Thermocouple. Measure at a height 1 ft below the roof surface which is not obstructed by any objects. Measurements  must be done at the middle of the roof surface not in corners.

  • Globe surface temperature. Thermocouple should be placed on globe surface and taped.  The tape should be painted with black color.

  • Inside roof surface temperature. Measurements  must be done by attaching the thermocouple on the inside roof surface which is opposite of the external roof surface thermocouple, i.e. the middle of the inside roof surface not in corners. Thermocouple much be taped and painted with same color as the inside roof paint.

  • Inside Heat Flux sensor. Measurements  must be done by attaching the heat flux sensor on the inside roof surface which is near (within inside roof surface 100mm) the inside thermocouple.

The images below provide further guidance. Click the left and right arrows to move between the images. To view a larger version of the image, right click it and follow your web browser’s instructions in the menu that appears.

Optional but recommended measurementS

  • Net solar radiation reflected back to space using albedometer. Albedometer is essentially a combination of two star pyranometers, one facing upward and one facing downward. The upward facing pyranometer measures global radiation (diffuse and direct solar radiation), while the downward facing pyranometer measures reflected solar radiation. Separate outputs are provided for each pyranometer, which can be recorded together on a strip chart recorder. Albedo, the fraction of incident radiation reflected by a surface, can be calculated from the output data (albedo = reflected radiation ÷ global radiation). Short-wave net radiation can also be calculated.

  • Albedometer CMA 6, with data-logger to measure direct and reflected solar heat flux. Measurements must be done at the middle of the roof surface not in corners. Must not be in area which remains in a shade and also receives background solar reflection.

  • Data-logger for recording Over/Under roof temperatures and heat flux reading.

  • Five thermocouples for measuring over roof temperature, under roof temperature, internal room temperature and globe temperature.

  • One heat flux sensor under the roof near the Thermocouple.


Recommended List of Sensors

  • Omega PR-T-24-SLE-1000. Special Limits of Erro Wire TC. Thermocouple Wire used to make thermocouples to measure the temperature of the roof surface. Quantity: 1.

  • DATAQ Model EL-GFX-DTC. Thermocouple Data Logger Supports K, J, and T Type Thermocouples. Quantity: 2.

  • DATAQ Model EL-USB-TC. Single Channel Thermocouple Data Logger Supports TC types K, J, and T. Quantity: 1.

  • Novalynx Globe Thermometer. One Type T thermocouples can be attached to surface of the globe and Second placed in the center of the globe. Globe can be hung on the roof. Globe Thermometer is used to measure radiant mean temperature. Quantity: 1.

  • Kipp & Zonen 0362960-002. CMA 6 Albedometer, 10 m cable and data logger. Used for measuring incident and reflected Solar flux. Quantity: 1.