You love him as a friend, but not romantically. You can’t force that feeling if it’s not there, and you shouldn’t enter into a romantic relationship with the hope that it will magically materialize someday. That’s dishonest and unfair to both of you. It will also ruin your friendship when the dating experiment fails.
I know that a lot of couples start off as friends, so your feelings for him could change over time. The odds are against it, in my opinion–you usually know pretty quickly if someone catches your romantic eye–but it could happen. If it does, if one day you suddenly see him in a different way, then that’s the time to consider pursuing a romantic relationship, not now. Don’t put the cart before the horse. This is one of those circumstances where “fake it ’til you make it” does not apply.
It sounds like you two have a great friendship, so don’t be in a hurry to change that. Once you pursue a dating relationship, your friendship will never be the same again, so I would keep the status quo until your feelings change. (If they change.) Good friends are as important as lovers, if not more so. You need both in your life, so don’t give up a sure friendship for a crap shoot at love.
Your guy won’t like it but you can tell him that you treasure your friendship with him too much to take a chance on love right now. He’ll either accept it or he won’t. Regardless of how he reacts, it’s the right thing to do.