Today's focus on energy and resource efficiency as well as sustainable construction has created a global inertia for the use of solar thermal heating and cooling for both space-conditioning and water heating. In many ways, this parallels the national commitment to use solar energy spawned by the energy crises in the 1970s. Solar energy systems to heat domestic water and for space heating are based on adding a collector to the heating system to capture energy from the sun. In general, this simply involves extending the heating/plumbing system to the roof of the house, where a solar collector is incorporated into it.
CDA published Design Handbook For Solar Energy Systems which includes an easy-to-use method for properly sizing a solar heating system to achieve desired solar contributions.
Copper is the logical material for solar energy systems because:
- It has the best thermal conductivity of all engineering metals;
- It is highly resistant to both atmospheric and aqueous corrosion;
- It is easy to fabricate and to join by soldering or brazing;
- It has been used both for plumbing and for roofs since metals were first employed in those applications.
Copper's thermal advantages mean thinner copper sheet can collect the same heat as much thicker gages of aluminum or steel sheet, and copper collector tubes can be more widely spaced.
Copper's resistance to atmospheric corrosion is well demonstrated by its service in roofing and flashing. Unless attacked by the sulfur or nitrogen oxide exhausts from utilities or process industries, copper has withstood decades—even centuries—of weathering.
Copper resists hot water corrosion equally well. Properly sized to keep flow rates below those recommended in Pressure System Sizing, and properly installed, copper hot water systems are, for all practical purposes, completely resistant to corrosion.
The ease with which copper plumbing systems are joined by soldering needs no special emphasis. Sheet copper fabrication is equally recognized for its ease and simplicity.