Title: Unit 2 Overview
Course: REEC 220 Solar Thermal Systems > Section: REEC 220 Solar Thermal Systems

Unit 2 Overview

Unit 2 Overview

There are a variety of components used in solar thermal systems.  There are many types of systems used in industry today.
Systems include:

- Direct Pumped
- Differential Controller
- Photovoltaic Operated
- Indirect Pumped
- Drain Back
- Integral Collector Storage (ICS)
- Thermosiphon

They all operate slightly differently, but most have the same components to make them function.  The most recognizable is the collector.  There are two main type of collectors: the Flat Plate and the Evacuated Tube.  However, there are also Glazed Flat Plate, Unglazed Flat Plate, Tubular, ICS, Non-separable Thermosiphon, Concentrating Collectors and Transpired Collectors.

The Solar Rating & Certification Corporation is the industry standard that certifies collectors for our industry.  SRCC provides a way to evaluate the performance of the systems.  There are two credentials that we spend the most of our time investigating SCRR Standard 100 and for solar collectors and the second is SRCC 300 Solar Water Heating Systems.

The videos in this section are specific to a closed loop glycol based system that comes as a kit from Stiebel Eltron.
Important Terms | Definition
SRCC | Solar Rating & Certification Corporation
Air Eliminator | Purge air from closed hydronic, solar thermal systems.
Heat Exchanger | The means of transferring energy captured from the collector to the storage fluid.
Flow Meter | Measures the velocity of the solar transfer fluid in a system.
Check Valve | A valve that only allows flows to go in one direction.  There are two types spring and swing type.  A spring type can be used in systems with AC powered pumps.  Swing types are can be used in DC pump based systems but they need to be properly installed or will not shut off.  The valve prevents thermosyphoning, the moving of the warm water in a tank to the cold collectors in the evening.
Pressure Relief Valve | A valve designed to open and relief some of the solar thermal fluid.  By doing so it reduces the pressure of the solar thermal fluid in the system.  Proper setting of the system is critical.  The pressure of the relief valve should be set to 5 PSIg higher than the expected pressure of the system.