A fresh air intake is not mandatory for your wood heater, unless the unit is installed in a mobile home or if the local building code or the manufacturer requires it. If the heater is installed in an open room, in a house that is more or less air-tight, combustion air will normally be easily replaced. In this case, the installation of a fresh air intake is not required. It must, however, be noted that a fresh air intake, even if it is not mandatory, will always provide the advantage of better balancing the house with regards to combustion air. If the house has a powerful mechanical exhaust system that may be used while the heater is burning (ex: range hood), a fresh-air intake will be required.