The amount of ventilation required for a gas heater will depend on the type of heater you are using and the size of the space it is heating. In general, gas heaters should be vented to the outside of your home to prevent the build-up of harmful gases, such as carbon monoxide. If you are using a ventless gas heater, it is especially important to make sure that the room is well-ventilated to prevent the build-up of harmful gases. It is also important to make sure that your gas heater has enough air to properly burn the gas and operate efficiently. If you are unsure about the ventilation requirements for your gas heater, it is best to consult the manufacturer’s instructions or contact a qualified professional for help.