[mrcaptainbob]

It sounds like it needs an air source. Ideally would be to have one from the outside of the house directly into the firebox, near the bottom. If that's not possible, maybe providing a PVC run as inconspicuous as possible and it's opening be pointed near and at the fireplace opening. Unfortunately, you might need something at least 4" diameter to provide enough air flow. If aesthetics are important, maybe two 3", one on either side and hidden inside of a tasteful looking round or square column to coincide with the general decor in that area.....Also, provide a way to close them off when not in use.