My hair dries slow on the length but roots really don't take as much. And I only use it on low heat low speed. I don't find it necessary to use high anything. I wouldn't use high.
You can see my wavy tutorials here: https://www.youtube.com/playlist?lis...ZNxhBHSXAW40OQ and my wavy blog is The Wavy Nation http://wavynation.wordpress.com