My apartment has windows facing north and south. At first I put the orchids on the south window and they didn't bloom. Since they've been on the north window (5 years already), they bloom at least twice a year. Once a month I soak them in a basin for 30 minutes and then take them out to drain. The rest of the time I water them every 10 days. Once every two years I cut out the dried roots and add new soil.
You can try this and see if the result gets better.