Heat Relief Fan Sizing
What size should the HVAC heat relief hood be for a powder coat booth and oven?
Q. I’m designing the HVAC system for a new industrial shop with a powder coat booth and a powder coat oven. What size hood and cubic feet per minute (cfm) should I use for the heat-relief hood in front of the oven doors? The oven has one set of double doors (5 × 10 ft.) with total door area of 10 × 10 ft. Oven dimensions are 16 × 13.5 × 13 ft., and the burner is 1.5 million Btuh. The exhaust fan on top of the oven is 1,500 cfm, and the oven recirculating fan is 14,000 cfm. Using the ACGIH manual for drying oven ventilation, the cfm is about 13,000, which seems very high. The building height is about 44 ft. —D.L.
A. You will want the hood to extend at least 5 ft. out from the oven wall. Use a large-diameter stack (24" minimum) and run it as straight as possible up through the roof. Install a damper so you can adjust it. I would not use a fan unless your building has significant negative air pressure. It would be best to rely on a normal hot air updraft. If you must use a fan, 13,000 cfm would be a disaster. You would pull way too much air from the plant and the oven. I would suggest a maximum of 3,000 cfm.
Related Content
-
Products Finishing Reveals 2023 Qualifying Top Shops
Each year PF conducts its Top Shops Benchmarking Survey, offering shops a tool to better understand their overall performance in the industry. The program also recognizes shops that meet a set of criteria to qualify as Top Shops.
-
An Altruistic Growth Strategy Puts People First
Professional Plating emphasizes investing in its team and fostering a supportive environment on the shop floor.
-
Curing Oven Basics
Simply heating up the substrate does not cure the coating. There are many variables to consider when choosing the best cure oven for your application...
