Wood heaters are available in several styles from ambient open fires like the Heatmaster series to more efficient sealed slow combustion wood fires that can burn for much longer periods and produce more heat with less fuel. The open wood fireplaces rely on a convective box to heat up an passively convect the hot air into the room but at the same time radiant heat is produced from the flames. The slow combustion wood heaters can be radiant or convective or a mix of both as in the case of some Lopi wood heaters and the Eureka Nugget.