Solar freeze protection: Why I prefer drainback solar thermal systems

摘要

The solar thermal systems market has essentially settled on two means of freeze protection: antifreeze or drainback systems. The latter are designed so water, or other fluid within the collector circuit, drains back to an interior storage tank whenever the collector circulator is not operating. A film of water, or tiny droplets of water, may remain in the collectors and piping components after drainback. However, this very small amount of water will not cause damage to the collectors or piping when it freezes.