How do you avoid the moldy smell when drying your clothes inside?

I'm not a fan of using the dryer for drying my cotton tshirts and cotton polos. I find that they shrink too easily even on low heat, and also shrink uneven and the front could be short, and back is long. I'm looking for some preshrunk polo's right now, but have yet to find any. I've also been looking at the niki dri-fit polos, I heard they were great and wont shrink as much. Anyway, when I hang dry my polos - they are 2 years old, I get this nasty mold smell. It takes them about 1.5 days to dry, and I've obviously noticed that when they hang outside they dry in an hour and smell great. What can I do to dry them inside and get them to smell normal? I'd like to use them in the dryer of course, but i'm scared of shrinking them with low heat, even when using cold water in the wash. please help ! Thanks!