Nitrogen oxide emissions from unflued space-heaters.

Measurements of the levels of nitric oxide and nitrogen dioxide emitted by radiant and convective space heaters revealed that the NOx emitted by the former was mainly NO2 while convective heaters produced mostly NO. As the air became vitiated, however, the convective heaters began to produce more NO2than NO. This evidence confirms that the nature of the NOx produced by a nunflued room heater depends on the type of heater and the conditions under which it operates.