How do you let a guy down easy?

So there’s this guy...and he likes me. I know because he’s come up to several of my friends asking for their help but every time we pass each other in the hall he barely looks at me. I know he’s just shy but honestly I’m just not interested in him. He’s really sweet though and I don’t want to hurt his feelings. One of my friends gave him my number and now he keeps texting me. I’ve played it distant polite but he keeps txting me. Starting up new convos. How do I show him I’m not interested with out hurting him?