|Non-conventional energy saving system
||Conventional energy system required.
|No electricity bills. Cost of Ventilator is recovered in the first year itself.
||Electricity bills are a monthly feature. Increasing cost of electricity makes electrically operated-ventilator a costly proposition.
|Not required heavy structures on roof.
||Heavy structures have to be mounted on the roof.
||Roof becomes weak due to vibrations with Conventional ventilators
|Assured operation for 24 hours a day, 365 days a year
||Can operate only when power supply is available & needed
|No maintenance costs as there are not armatures / field coils/switches.
||Maintenance cost will be required