My hive is only in direct sunlight for a couple of hours a day now. Being concerned about heat loss, I insulated the three sides of the hive that do not receive any sunlight. I was wondering if this might create a heat imbalance inside the hive (one wall possibly being colder than the others) causing the bees to cluster to one side.

I asked around, but none of the beeks I know insulate their hives -- unlike mine, theirs are in sunlight all day during the winter.