heat vent; exhaust vent
An opening or outlet for discharging hot air or waste heat, typically on machinery, electronics, or buildings.
Please do not block the computer's exhaust vent.
This machine has a heat vent on the side.
Standard kanji spelling using 排 (exhaust/discharge).
Alternate spelling using 廃 (waste/abandoned). Less common but seen in some contexts.
Compound of 排熱 (はいねつ, 'exhaust heat') + 口 (ぐち, 'opening/mouth').