Cabinet exhaust hood commonly known as the fume hood, and airtight cover similar. Just cover can be opened or set on one side all operating holes. The operating personnel can will hand in the enclosure, or people directly into enclosure work. Small parts of painting cabinet, chemical lab ventilation ark cabinet exhaust hood is the typical structure. Hood side completely open (work window), ark of work on ventilation of mouth which air distribution impact, air distribution and directly influence the cabinet exhaust hood effect on work. Such as work of airflow velocity distribution is mouth uneven, harmful gases from the small speed escaped into the interior, for this, deal with the ark of the ventilation work analysed. Fume hood shall be low and high temperature fume hood of the points.

Low temperature fume hood
When the temperature of the harmful matter than the surrounding low temperature, called low temperature fume hood. Cold is shown in the fume hood says the upper row ethos movement. The work of inhaled speed for hole 150% of the average flow velocity, and the average flow velocity is only 60%, harmful gas from the lower will escape. In order to improve the situation, which should add baffle, and put in the ark of the ventilation vent tap the lower.

High temperature fume hood
Used in the production of large quantity of heat process of says hood, called the high temperature fume hood. The thermal process in which the heat flow ventilation to rise up, if like cold process, to breathe in the lower, the harmful gas from the upper to escape. Therefore, the thermal process ventilated ark in upper wind must be. For heat unstable says, can be in all set up and down the ventilation system. With the change of heat inside ark, adjust the up and down the exhaust air proportion, and cause the work to a more even distribution of the holes speed.