Do vent-free gas heaters take all of the oxygen out of the room?
All products which burn gas and draw combustion air from the living space “take oxygen” from that space. This includes gas cooking ranges which are vent-free units. The owner’s manual on our products and any local code official will inform about the need for make-up combustion air. A typical well-insulated home still has sufficient air movement to completely exchange indoor air for fresh outdoor air several times per hour. If this air exchange did not take place, normal human breathing would eventually take all the oxygen from that space. This normal air exchange provides more than enough make-up air for the vent-free heater. Vent-free heaters have an ODS or Oxygen Depletion Sensor which automatically shuts off the gas supply in the rare event that the oxygen level in the room falls to 18%. This is well above unsafe levels as established by ANSI (American National Standards Institute).
