Having this device installed at my home I am know just tension free with regard to power failures at any time.I have been using oit since last six years and have faced just no problem.It is extremely easy to handle and demands no additional maintenance expense.
Only the liquid is to be replaced after every few months, depending upon the usage.Servicing is not at all costly and this device is also environment friendly and does not consume much electricity.All necessary electronics like fan, lights run even during power failure.
I am really happy with my purchase and the cost when I purchased it was quite reasonable and recently my friend purchased it and is satisfied with this buy.