These systems have many advantages:
- They can use simple water as a solar fluid for lower cost.
- They are very efficient if they are planned and installed properly.
- They are ideal where the installation will lie idle for extended periods.
- Since the system empties when it switches off, the solar fluid has a long life.
It's also important to consider these disadvantages:
- They cannot be used in regions with harsh winters.
- They cannot be used where freezes occur regularly.
- They cannot be used where there is significant snowfall.
- Pipe runs must be installed for quick and complete drainage.
- The collectors must be above the storage tank.
- High-head pumps use more electricity.
- Material and installation requirements are more complex.