Coby (5 months) doesn't nap much during the day and hasn't ever - oh some days I wish he would unless I put him to bed. He has a lot of energy. Like you, the only way to get a nap is to cover the kennel so he's not "missing something".
Are you taking walks? Coby will nap if he gets a good walk. They are like kids, if they get that "walking tired" like a toddler, they can get a little squirrely. They act like they've had a big bowl of sugar. Walking might help either the day naps or the nighttime sleeping. I know that it's frustrating. I'm waiting to leave puppy-dom to get more daytime naps. My 10 year old Shi Tzu sleeps about 23 hours a day.
Didn't you say in another post you were getting ready to go back to school? Will he be in a kennel or pen while you're gone?