We carry a full line of solar energy products. These systems are extremely well engineered. Some models use a small photovoltaic panel to power their circulating pump. Others use natural thermosiphon to circulate the water through the panel, thereby eliminating the need for ANY power source. If you’re interested in a clean, reliable, and environmentally friendly heat source, we can design a solar powered radiant system for you.
Flat Plate Collectors
Most people are somewhat familiar with standard flat plate solar collectors. As illustrated above, these collectors are basically a highly insulated box containing a grid of copper pipes bonded to a flat black copper absorber plate. Special glass enhances solar absorption.
The Sunda evacuated tube collectors are an entirely different approach to solar water heating. Instead of many water-filled copper pipes, these collectors use multiple vacuum-filled (if indeed a space can be “filled” with a vacuum) glass tubes, each with a tiny amount of antifreeze hermetically sealed within a small central copper pipe. When heated by the sun, this antifreeze converts to steam, rises to the top of the tube, transfers its heat to a collector header, then condenses back into liquid and repeats the process.
The Sunda “Seido 5-16 Tube” evacuated collector
Because thermal energy doesn’t easily transfer through a vacuum, the heat stays within the evacuated tube and passes to the collector header. This is a huge advantage because a standard flat plate collector radiates much of its accumulated heat to the surrounding atmosphere like any other hot object.
The evacuated tubes are also completely modular. Although rarely necessary, one or more tubes can be removed and replaced without affecting the other tubes in the array. There is no actual liquid transferred from the evacuated tube to the collector header…just heat. Evacuated tubes also start absorbing heat earlier in the day than flat plates due to their convex design, and the tiny amount of antifreeze within the tube is freeze protected down to -50 degrees below zero.
Below is the SRCC certification for the “Seido 5-16” evacuated tube collector: