izzy knows all about layers, he's got them mastered
but yeah, you can just render just the shadows and the background
just put everything onto a seperate render layer and then turn off the visibility of all the fridge pieces in the render stats (not the channel box)
you can do turn them off quickly if you select them all and then opent he Attribute Spread Sheet
that's a "Ch" pronounced as a "K"
Computer skills I should have:
Objective C, C#, Java, MEL. Python, C++, XML, JavaScript, XSLT, HTML, SQL, CSS, FXScript, Clips, SOAR, ActionScript, OpenGL, DirectX
Maya, XSI, Photoshop, AfterEffects, Motion, Illustrator, Flash, Swift3D