Determine your location on the map. The sizing depends upon region. To determine hot water usage – assume 20 gallons of hot water consumption per day for the first and second family members and assume 15 gallons per day for each additional family member. (i.e. 4 person family will use approximately 70 gallons per day.) Choose next largest solar storage tank capacity necessary. Example : Family size 4, an 80 gallon storage tank is suggested. The number of collectors and sizing will be determined from the sizing map. INDIRECT “I” ,“IPV ” SYSTEMS (Closed Loop) The Indirect System offers excellent dependability and performance. As the sun shines on the collectors, non-toxic antifreeze is circulated through the “solar loop” by the pump and heat is transferred into the tank. The potable water in the tank never flows through the collectors. This prevents corrosion or scale buildup in hard water areas. These popular systems have proven to be dependa ble in installations across the U.S. and worldwide. Freeze protection is assured due to the antifreeze in collectors and exposed piping. NOTE : For IPV (Formerly CPV) Systems, use the same chart. DIRECT “D” ,“DPV” SYSTEMS (Open Loop) The Direct Systems are highly efficient due to the direct circulation of water from the storage tank to the collectors. As this water flows through the “open loop” d u ring a typical day, it is heated and then stored in the insulated tank. Systems are usually sized to deliver 15 to 25 gallons of hot water per person per day. This system performs best in moderate climates. The collectors and exposed piping are protected from freezing by a control recirculation feature that circulates warm water during freezing conditions and a fail safe thermal valve. DRAIN BACK “DB” SYSTEMS The Drainback System is one of the top performers in the U.S. in both total energy output and efficiency. The simple design eliminates many components. Only potable water is used in the indirect system instead of chemicals so no maintenance is required. The collectors and exposed piping drain each time the pump is turned off, assuring freeze protection. COLLECTOR SIZING In the sunbelt, zones A, B, and C you will need one square foot of collector for eve ry 2 gallons of storage, i.e. 80 gallons of storage will require 40 square feet of collector area. In the remaining zones D, E, and F you will need one – two square feet collector area for every 2 gallons of storage, i.e. 80 gallons of storage will require 60 square feet of collector area. In this case you will need two AE- 32 (64 sq.ft.). SOLARIZING EXISTING WATER HEATER “DX” DRAIN BACK RETROFIT Convert existing 40/52 gallon electric water heaters or utilizing 40/52 gallon storage tanks for preheating existing gas water heaters. These systems can be expanded to a larger system by adding additional storage and/or collectors in the future.

map here Region System Number of Collectors Collector Model Storage Tank Capacity A I-80-52 2 AE-26 80 GAL. A-B-C I-80-64 2 AE-32 80 GAL. D-E-F I-80-80 2 AE-40 80 GAL. A-B-C-D I-120-80 2 AE-40 120 GAL. E I-120-96 2 AE-32 120 GAL. F I-120-120 2 AE-40 120 GAL. Region System Number of Collectors Collector Model Storage Tank Capacity A D-66-32 1 AE-32 65 GAL. A-B D-66-40 1 AE-40 65 GAL. B D-66-52 2 AE-26 65 GAL. A D-80-40 1 AE-40 80 GAL. A-B D-80-52 2 AE-26 80 GAL. A-B D-80-64 2 AE-32 80 GAL. A D-120-52 2 AE-26 120 GAL. A-B D-120-64 2 AE-32 120 GAL. A D-120-80 2 AE-40 120 GAL. Region System Number of Collectors Collector Model Storage Tank Capacity A-B DB-66-40 1 AE-40 65 GAL. C-D DB-66-52 2 AE-26 65 GAL. E-F DB-66-64 2 AE-32 65 GAL. A DB-80-52 2 AE-26 80 GAL. A-B-C DB-80-64 2 AE-32 80 GAL. D-E-F DB-80-80 2 AE-40 80 GAL. A-B-C-D DB-120-80 2 AE-40 120 GAL. E DB-120-96 3 AE-32 120 GAL. F DB-120-120 3 AE-40 120 GAL. Region System Number of Collectors Collector Model Storage Tank Capacity A-B-C D-40-26 1 AE-26 40 GAL. A-B D-52-26 1 AE-26 52 GAL. D D-40-32 1 AE-32 40 GAL. D D-40-4- 1 AE-40 40 GAL. D-E-F D-52-40 1 AE-32 52 GAL. “D” Systems may not be appropriate for areas that experience temperatures below 35°F.