Title: Unit 5 Overview
Course: REEC 220 Solar Thermal Systems > Section: REEC 220 Solar Thermal Systems

Unit 5 Overview

Unit 5 Overview

The collectors absorb radiation energy from the sun and transfer that energy to the solar thermal fluid.  There are three main types of absorber plates: painted metal, black chrome and TINOX.  The TINOX has the highest absorption rate, while the flat black painted object has the weakest.  The energy in the visible light spectrum contains the highest amount of irradiance.  ASHRAE devises standards that determine the best flow rates and thermal transfer of fluids in solar thermal systems.  SRCC tests the collectors to verify conformity to the standards.

For most every day domestic hot water heating systems, the flat plate collector is the way to go.  They have an ideal absorption and range really suited to heating of water.  Their life expectancy is long, and the ambient temperature that they can collect is wide and tolerant.  Evacuated tube generally has less life expectancy and less capture area.  They have an advantage of capturing at a wider range sun angles.  They generally are most productive when the temperatures get above 120°F.  If the operation calls for a hotter water temp, evacuated tube is the way to go.
Important Terms | Definition
ASHRAE | American Society of Heating, Refrigeration and Air Conditioning
Unglazed Flat Plate Collector | Does not have glass or other transparent covering. These collectors are commonly used for swimming pool heating systems.
Glazed Flat Plate Collector | Has a cover of glass or other transparent material. Common type of collectors.
Hot Air Collector | Heats air rather than water in the collector. They are most commonly used for space heating applications
Evacuated Tube | A system that uses evacuated tubes of glass with a copper tube filled with heat transfer fluid.