... pool, sub district; 2. Economic cost; 3. High efficiency Solar water heater projectWorking principle:1) Many-tubes-connected makes the ... for heat transferring. When the discrepant temperature of the solar collector and water tank reaches the set value, the ... steel / aluminum alloy, durable and stability performance, well wind resistance solar vacuum tubea) Size: Φ47x1, 500mm / Φ58x1, 600mm / Φ58x1, ...