No apologies needed. We all have our frame of reference. This is an HVAC site that also discusses fireplaces. You go on a Hearth related site or home inspectors and I'm sure you'll see things that perturb you. Just how it is. However, if we're open and objective, we all learn. I never thought of applying COP to hearth products before but the concept does bring another dimension into choices.
Thanks for participating and please don't stop!