Batch Collectors use evacuated tubes to heat the water directly. The water circulates within the inner tube through passive convective flow and heats the tank of water very effectively.Because the water is in direct contact with the inner glass tube the heat transfers very well.The performance of the tube itself can reach 80% but because of the heat losses of the tank, the total system efficiency are around 70- 75% (depends on ambient temperatures). Batch heaters are used in simple gravity style systems such as outdoor showers, recreational cabin, or off grid home.They are easy to set up.
