I have a Lopi/Travis nexgen-fyre medium flush wood burning insert. It was installed with the correct clearances from the manufacturer. However, when I run it, the mantel above it gets quite hot. I have measured a max temp of 170 degrees fahrenheit on the underside of the mantel without running the stove too hard. Is this safe? Should I install some kind of a heat deflector or hood? I was told by one fireplace store employee that the hoods that go on over a fireplace and stick out about 4" do not do much. Has anyone installed one of those over an insert? If so, how much of reduction in heat on your mantel did you see?