These systems have the following advantages:
- They are simple, cheap and easy to install compared to most active systems.
- They offer more collector placement options than an ICS setup.
- They can run on a PV-powered pump.
- They are extremely efficient when in operation.
It's also important to consider the disadvantages:
- There provide no freeze protection at all.
- They are susceptible to mineral buildup from hard water.
- Some of the specialized components are less reliable than standard equipment.
- They waste a small amount of water every time they switch off.