What is the necessary height for exhaust discharge above adjoining grade?

The correct height for exhaust discharge above adjoining grade is essential to ensure safety and performance, particularly with regards to preventing the recirculation of exhausted air and maintaining air quality. Discharging exhaust at a height of 30 feet helps to ensure that any exhaust gases are elevated well above the area where people may be, effectively reducing the risks associated with inhaling potentially harmful fumes. This also helps in reducing impact on surrounding buildings, minimizing the chances of the exhaust affecting nearby windows, doors, or ventilation intakes.

A discharge height of 30 feet is a best practice that aligns with national standards in many contexts, ensuring proper dispersion of exhaust emissions and preventing problems like downdrafts, which can occur when exhausts are placed too low. The height is particularly relevant for specific applications, such as commercial kitchen hoods or industrial exhaust systems, where significant volumes of gases need to be dispersed to avoid health risks and maintain compliance with regulatory requirements.