warm-air circulation. The flame burns in a closed
satisfactory than the unvented type because there is
combustion chamber, and the heater vent carries away
less danger of carbon monoxide poisoning. A panel
the gases (fig. 4-5). The flow of heat is maintained by a
unit is one type of vented unit (fig. 4-6). It may be
motor-driven fan and is controlled by vanes, fins,
recessed or surface-mounted in either an interior or
louvers, or diffusers. This type of unit is more
exterior wall with a vent properly insulated and run up
Figure 4-5.Rear view of a vented gas-fired space heater.
Figure 4-6.Gas-fired panel space heaters.