Thank you very much for your reply Richard!
At this stage,i dont feel comfortable getting them outside unprotected as there are lots of things that can happen to them like snail nibbling,breaking by the wind,animal damage or their leafs wilting from not being able to cope with the dry noon and afternoon conditions we have on hot(yet normal to below normal temperature) days we get from time to time. Also,due to this being a really cool and much below average,spring,i am not getting very fast growth from my bananas yet which would prolong their acclimation and growing up time. So i thought i would save me time and worry and acclimate in my warm basement first,under controlled,safe conditions till they are big enough to be able to survive the cruelty of the outside world
Then i plan to do as you describe to acclimate to more sun and real life conditions
The weather should improve by then and they will continue to be in active growth mode for more months!