Uh-oh! This is one of those 10 beekeepers / 11 answers questions. I was taught, in theory, the side with the larger gap should create bee space for the top frames and reduce the building of bur comb and propolis. But, as with all theology, you can hear very wise, good and gifted beekeepers tell you just the opposite. In practice, I have found little difference. Some manufacturers produce covers the same on both sides. Some beekeepers flip according to seasons, activity, robbing, bones and tea leaves. However, what I do pay big attention to is the "noch" on the rim of the inner cover. I am currently obsessed with ventilation in the winter, having recently frozen some bees. My notches are now down to vent out moisture. (During the summer, I have lids propped or wine cork holes open, and entrances unrestricted to vent.) My hutch is, the direction of your inner cover will be the least of your excitement this first year.