Covering bathroom fan with insulation

My bathroom fan in my attic was installed without any insulation on top of it. Therefore, it likely acts like a heat sink between my bathroom and the attic. I was thinking of enclosing the metal casing in some sort of insulation (ie: rigid board or fiberglass batt) to stop the heat transfer.

Does anyone on this forum have any experience insulating a bathroom fan?

Thanks

You must read the operating and installation instructions. If the unit has an internal light, they may have a requirement for no insulation contact to prevent excessive heat buildup. There would normally be warning stickers on the unit, but depending on its age, them may no longer be there.

The unit is quite new as I installed it myself about 1 year ago. The unit does not have a light so the only heat generated would be from the fan motor. This is not an energy star unit so I don't know how much heat it actually generates but here is the link to the fan

http://www.nutone.ca/product-detail.asp?ProductID=10905

There is nothing in the PDF files in the above link that indicates that the unit cannot be covered in insulation.

Thanks