Today's Solar Thermal Heating Systems represent the best of New Technology combined with the benefits of Traditional heating systems.

The main types of Solar collector fall into three groups:

• Unglazed
• Glazed Flat Panel
• Evacuated Tube

Don't be fooled by the sales people as each type and variation of these has its place in the market.

Let's take a look a the differences

Efficiency, or to be specific efficiency at the intended operating condition, is important but there are many ways to look at it. But the basics come down to two main areas: optical efficiency and thermal efficiency, defined by η0 and a1, a2 respectively. Here's an example of how they might look:

What do they mean?

η0 is the optical coefficient and is a measure of how much light (over a defined bandwidth) is caught by the absorber.

a1, a2 are the linear and quadratic heat loss coefficients. Here's an example of how they might look (note - different manufacturer's panels will perform differently):

The efficiency graph (Figure 1) gives an impression of the performance of the panels, however, this can be misleading. If we examine the performance at different levels of Irradiance (Sunshine) and look at the area where Solar Water Heating Systems operate, then the picture looks different again.

Especially at low Irradiance levels (Weak Sunshine) the Evacuated tube type will tend to perform better than the Glazed Flat Plate type (Figure 2) when providing Domestic Hot Water whereas the Glazed Panel will perform better when having a requirement for lower temperatures.

Which performs best depends on the particular panels!!

Fabrum Energy Solutions will examine efficiency based on what is important to you.

We offer the best solution whether it's Evacuated tube, Glazed Flat Plate or Unglazed.