Rheem SolPak Use and Care Manual - Page 20

Section 4: Installation Requirements- Specific 4.9.6 Dowfrost HD HTF To ensure maximum effectiveness for corrosion protection, the glycol inhibitor package is designed for a minimum 25-30 percent concentration of glycol in water. Table 4 shows the concentrations of Dowfrost HD required to provide freeze and burst protection at various temperatures. Use the mixture most appropriate for your climate. Do not use a higher glycol to water concentration than necessary, as this will adversely impact the relative heat transfer efficiency of the solution. examples only and should not be regarded as specifications. As conditions are not within our control, we do not guarantee that freeze damage may not occur at temperatures other than shown. Water used to dilute the HTF must meet certain minimum standards for purity. Impurities in the dilution water can increase metal corrosion, reduce the effectiveness of corrosion inhibitors, increase inhibitor depletion rate, and cause the formation of scale and other deposits on the heat exchanger's internal heat transfer surfaces. Generally, for an extended margin of protection, you should select a temperature that is at least 5°F lower than the expected lowest ambient temperature. These figures are Distilled or deionized water is required. The HTF pH level must be maintained between 8 and 10 to minimize corrosion and glycol oxidation in the piping system. Section 5: System Start - Up Procedures Throughout the installation procedures outlined in Section 4 ,emphasis has been placed on the correct procedures for plumbing and wiring the components, checking for plumbing leaks, pressurizing the collector glycol loop, and eliminating any trapped air that can impact fluid quality and pump performance. Having completed these tasks it is time to start up your solar water heating system. When the glycol loop has been fully charged and the pressure is around 25 psi (check the pressure gauge,(No. 10), set the differential controller to the "Automatic" setting. This will activate your circulating pump. The controller allows you to set the "on" differential. Adjust the valve settings in accordance with Section 6. SOLAR COLLECTOR (OPTIONAL) Solar Components 20 ELECTRICAL COMPONENTS