EagleSun solar thermal drainback system

Indirect Pressurized System

Features

• Accommodates climates where freezing weather occurs more frequently.
• A Differential Control senses temperature differences between water leaving the collector and the coldest water in the bottom of the storage tank. When the temperature of the water in the collector is hotter than the water in the tank, the differential control operates the circulating pump.
• A heat exchanger is located within the storage tank to maximize the heat transfer from the antifreeze solution to the coldest water in the storage tank.
• A small photovoltaic solar panel option (which generates electricity from the sun) is available to operate the circulation pump, further reducing traditional energy consumption.

Drainback System Features

• Removes all water from the collectors, and their pipelines to ensure they never freeze when the system is not producing heat (drain mode). Each time the pump shuts off, the water in the collector(s) and piping, which are mounted at a slight angle, drains into the insulated reservoir tank.
• A sight glass attached to the reservoir tank indicates that the collector(s) has been completely drained.
• A Differential Control senses temperature differences between water leaving the collector and the coldest water in the bottom of the storage tank. When the temperature of the water in the collector is hotter than the water in the tank, the differential control operates the circulating pump.
• Less moving parts allows for fewer maintenance concerns.