bedgar, my recommendation would be to replace the existing unit with a better grade unit than what is there right now. Get a reputable HVAC contractor to do this for you. When it comes to Modular/ Mobile home installations, there are particulars with proper clearances & the units intended use. More than likely, the unit that is in there now was only intended for athstetic purposes, not necessarily as a heat supplement. Your reference to a "Traditional" brick fire place which is commonly found in your stick built homes are only intended for athstetic's, not for heat supplements. Those particular units, you can indeed put an insert in them for use as a heat supplement. While you are at it, check the existing chimney, you may want to replace it to match the use of the intended use of the wood heat. More than likely it is a double wall stainless stack in there right now. Keep in mind, those chimney's do not have a long life expectancy, if possible, I would consider a block chimney with a tile liner, much safer & will last for many years. Another alternative that lenny mentioned is a pellet stove, which are pretty effective & burn quite clean & do not require a "chimney", they are power vented like a high efficiency gas boiler. Wood is nice, but just remember this, there is a lot of heat in it before you can burn it! LOL!-Mezz