Ventilator Improvements for Reducing Radiometer Frost, Snow and Ice Accumulation

Poster PDF

Description

The Atmospheric Radiation Measurement (ARM) program provides high quality radiometric data traceable to the International System of Units (SI) through World Radiometric Reference (WRR). The National Renewable Energy Laboratory (NREL) and ARM, through the Radiometer Calibration Facility (RCF) at the Southern Great Plains (SGP) site, provide broadband radiometer calibrations (BORCAL) of radiometers deployed in the SKYRAD, GNDRAD, and SIRS instrument platforms. Both NREL and ARM continue to improve radiometric measurements through the introduction of new methods and system modifications to reduce uncertainty in calibrations and field measurements. This poster presents a review of testing performed under ENG0003807, with the objective of improving the reduction of frost, ice, and snow accumulation on radiometers mounted in Eppley Model VEN ventilators. The Model VEN ventilator is utilized with Eppley pyranometers and pyrgeometers at ARM Program SIRS and SKYRAD sites for downwelling broadband shortwave and longwave radiometric measurements, and at GNDRAD sites located in cold climate regions for upwelling longwave and broadband shortwave measurements. As part of ENG0003807, testing is being performed at NREL with modified sunshields used on Eppley Model VEN ventilators, and at the ARM Program AMF3 Oliktok Site with increased voltage to ventilator heater coils, heating pads under sunshields, and modified ventilator sunshields. The results will show the performance of each test scenario and a recommendation for deployment.