This post may cross the line on DIY - if so please accept my apologies and remove.

I have a Daikin 3-Port Ductless system installed by a local contractor in my basement. Currently I have two of the three ports used on two rooms in said basement. I have recently completed an addition of about 450 square feet on to the back of the basement and am having a third indoor unit installed next week by the same contractor.

This new expansion is divided in to two rooms - one will be used for a workshop approximately 10-12 hours per day (my wife and I run a small service business out of our home) and the other room will be used for shelved storage of moderately delicate items. These two rooms will be separated by a framed and insulated wall with a door.

Of course I am having the new third indoor unit installed in the workshop that we will be spending most of our time in. I would like to at least partially moderate the climate in the storage room as well by "sharing" some of the air in the workshop. Is there any way to accomplish this by installing a couple of vents in the separating wall or perhaps even a small fan or two to blow air from the workshop in to the storage area (or vice-versa)? I don't need the storage room to be necessarily "comfortable", just keep the temperature above 60 in the winter and below 90 in the summer (we are in the Atlanta area). The side benefit would also be to keep the humidity down a little.

I understand that without either a direct 4th system or a supply/return setup that I won't be able to have any kind of strict control over the climate - I just need a solution to "take the edge off" so to speak.

Thanks for any help you can offer.