A Manual Three-Way
2.7.8 Pipe and Tank Insulation, The most efficient solar heating system
cannot deliver heat it has lost from piping and tanks. System insulation must be
thermally adequate, continuous and durable. Regular inspection and maintenance
is necessary to ensure the insulation and jacketing have not been damaged.
At a minimum, all solar piping under 1 inch size (nominal) should be insulated to R-
4. All piping 1 inch or larger should be insulated to at least R-6. Exterior piping of
all sizes benefits from insulation to R-7. (Figure 2-45)
Protection from moisture and ultraviolet radiation is necessary for all exterior
insulation. (Table 2-2)
Polystyrene or polyethylene should never be used for solar applications. These
materials melt at a temperature of 165F, well below the expected temperature for
piping in most parts of all systems.
2.7 COMPONENT OPERATION