Non-flued Heaters
Non-flued heaters – also known as unvented heaters, ventfree heaters or flueless fires may be either permanently installed or portable, and sometimes incorporate a catalytic converter. Non-flued heaters can be risky if appropriate safety procedures are not followed. There must be adequate ventilation – which is a problem due to the ventilation cooling the house, counteracting the heating – they must be kept clean, and they should always be switched off before sleeping. If operating correctly the main emissions of a non-flued gas heater are water vapour and carbon dioxide. If there is incomplete combustion, toxic products such as carbon monoxide and nitrogen dioxide form. If ventilation is poor, the carbon dioxide level in a room will begin to increase, and prevent the release of carbon dioxide from the blood to the room air (see lung) way before the decrease of available oxygen (or carbon monoxide forming) becomes a problem.
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