Yes, it will work fine. It won't cause any damage.I have a 2011 MBA 11" and realized I have an older MBA charger around my house. Would I be able to use this with my MBA and not have to worry about any damage? It is the T-shaped charger but for a MBA.
I've been using my old Macbook Pro 13" charger with my new 11" MBA for months with no problems. Make sure that what ever charger you are using has a current rating at least as big as the Macbook Air. It is marked on the side of the charger, I need a magnifying glass to read it though.