SOLAR COLLECTORS AND SOLAR MODULES

The term solar solar collector refers to solar panels for hot water and air heating requirements. The type of solar collectors vary with the intended goal – water heating, radiant floor heating, pool heating, air space heating - and the climate where they are going to be applied.

Solar modules (also referred to as PV modules and solar generators) are used to convert sunlight directly into electricity.

Drainback Solar Systems

Like anti-freezing systems, drainback solar systems are also specially conceived for cold climates. They offer lower maintenance and longer life and reliability, but they pose higher demands in terms of design.

Antifreezing Solar Heating Systems (Active-Closed Pressurized Systems)

Cold climates demand more complex systems. Batch/ICS systems are clearly inadequate in freezing conditions, and thermosyphon solar systems involve some limitations.

One of the most popular solutions for freezing climates comprises a relatively complex system with an antifreezing fluid (glycol, usually), a differential controller, an expansion and a storage tank, and a heat exchanger and sensors and valves.

The Open-Loop Direct System

If you live in a moderate or hot climate, without freezing problems, you may choose a simple solar heating water system using a pump and water at the collector level. This system is called technically an Open-loop direct system.

Thermosyphon Solar Systems

Thermosyphon systems are also a simple solar heaters, very efficient and very popular in moderate and hot climates. They are cheap and demand no pumps or special controls, and can also be installed in colder climates.

Batch ICS Solar Systems

Batch solar systems (or ICS) are the simplest and, in a way, the oldest solar heating systems. They haven’t pumps, separated storage tanks or anti-freezing. They combine a solar collector and a storage tank into one single unit, and in their most simple version they are a mere water tank within a glazed box.

SOLAR HOT WATER HEATERS: THE DESIGNS

The designs and the type of components of the solar water heaters vary a lot. But we may consider five main designs, with different costs and complexities.
Solar Water Heating Designs
Main solar water heating designs:

- the batch ICS solar systems (an ultra-simple system for moderate climates);
- the thermosyphon solar systems (for moderate and other climates);
- the solar open-active heating systems (for moderate and hot climates);
- the drainback systems (cold climates);
- the anti-freezing pressurized systems (cold climates).