Some people, such as Al, have their pump and filter in a pool house. Many people, me included, have mine outside and exposed to the elements. (I do take my pump inside the shed during the winter and drain and cover the filter.) I'm pretty sure that being exposed to the element does contribute to shorter life of the equipment, but Al can tell you for sure.

One question unrelated to your pump and filter. You say that you chlorinate with tabs in a chlorinator. I assume these are trichlor tabs which are stabilized. Do you monitor your cya level throughout the summer and stop using the tabs if the cya level gets too high?