Sorry , answering my own query after checking the fee structure sent by the previous poster. they do have a fee if the account become inactive or dormant for 2 years.
the page is saying following
Inactive or Dormant chequing and savings accounts that have been inactive/dormant for 2 years or greater (up to 9 years): $20.00 each year
(charged starting the first January after 2 years of inactivity)
hence it is better to close them if you don't wish to keep them active. pls post here what you find about closing fee. thx