air con pipes moist with condensation in engine bay normal?

[omodos]

Hello all, well not sure how many of you have a habit of feeling around the engine bay after a long drive on hot hot summer day ? i did, and found that the alloy pipe no.3 that must be the refrigerant pipe was damp with condensation , bearing in mind i had the air con on, is this normal? and another thing is at what temp must the radiator fan come on? had the car for 5 years and not heard the fan come on once??? and temps do get real hot out here, i even left it in park for 5mins bit still no fan kicked in....i uess it must work at some point otherwise i would have toasted the engine by now...thanks