Precision ovens generally circulate air either horizontally or vertically. To keep the interior dust-free, a high-temperature, high-efficiency filter (Class 1000 or Class 100) is added at the air outlet. After the air in the oven passes through the return inlet, part of it is exhausted outside through the exhaust port, while the rest is reheated in the circulation duct and finally returns to the chamber through the filter.
Besides filtering the air, dust generated during operation must be kept to a minimum, which calls for high-end materials and electrical components; for example, heating tubes must not shed particles at high temperatures.
Note: it is best not to use the oven for long periods outside a cleanroom; the air contains many particles, and long-term use will greatly shorten the life of the air filter.
Common cleanroom oven specifications from Dongguan Xinzhou / Hubei Xinhai, for reference:
