Can insert efficiency be boosted?
I have a 60's split-level home with a daylight basement, massive stone surrounding fireplaces on each level. The basement where we would burn wood has a 20% efficient old Country Hearth insert. I looked at the new inserts in a store and they are smaller but have the pipes with holes drilled in them at the top of the firebox. I'm wondering if we installed the stainless steel tubing liner in the chimney and added our own pipes with holes drilled in them to the top of our insert, could we change the efficiency without having to rip it out and buy an expensive new insert. I don't know the construction, if air is blown through the pipes or what. Our fireplace has a blower but DH thinks it only recirculates room air and that we need to bring in outside air, perhaps through a partially sealed off window.
My MIL had several large trees removed at her house so lots of possible firewood, and it would be nice to have a backup in case of prolonged power outages for heating the house. We did use the fp when we had a 3.5 day blackout once and it did work enough to heat the house and cook on, but I would want the efficiency to be better to use it frequently.