Upvote:-3
Update: The embassy website is not clear. You are recommended to call up airlines and clarify it.
You won't need a Transit visa.
Since, its not the primary Airport, the sleeping situations and facilities will be tight. But noone will prevent you from staying there for 20 hours and catch the next flight.
Reference - http://www.thaiembassy.org/telaviv/en/services/685/17388-Entry-to-Thailand.html
To be on the safe side, give a call to your Airline.
PS: There is Visa on Arrival for Indians. It costs 2000 THB (Roughly 4500) and you have to show enough funds (10k THB, ATM slip will do) to get out of Airport. I have covered Bangkok in a single day in such a transit.