Gypsum Board

CHALLENGE

The process at this gypsum board plant produces excess heat and moisture that must be ventilated effectively from the building. The existing ventilation system was not removing enough built-up heat and moisture, resulting in extreme conditions in parts of the plant. Temperatures throughout the plant averaged about 15° above ambient, with peak temperatures exceeding 150° in the hottest areas. These conditions required workers to take frequent breaks and switch out periodically to comply with OSHA and ASHRAE recommendations.

DESIGN

Moffitt’s focus was to ventilate the excess heat as close to the source as possible. This would remove the excess heat and moisture previously trapped in the plant thus lowering the temperatures on the working floor and roof. It was also found that general plant ventilation would be beneficial by increasing air changes, increasing air movement, and lowering temperatures in low heat producing parts of the plant. Ambient spot cooling was introduced in the paper handling area to provide cool fresh outside air on top of employees.

The Moffitt goal was to provide a 5°F to 25°F drop in temperatures for each building zone with a tolerance of +/- 3°F for each area.

SOLUTION

Moffitt uses computational fluid dynamics (CFD) modeling to visually show the air temperature trends inside the plant. This helps us make decisions to best ventilate the plant by seeing the airflow patterns and positioning ventilation equipment in the most effective places to evacuate heat.

Based on the results of the CFD analysis, the new ventilation system consisted of (15) 10’ W x 25’ L MatrixVents, (10) 40,000 CFM upblast fans and (4) 25,000 CFM hooded roof supply fans. Moffitt recommended leaving the existing operable equipment on to aid in exhaust. The new total building exhaust airflow increased by 340% from the original system.

RESULTS

Temperature sensors were placed around the plant to gather temperatures. Over the test period results exceeded expectations in every target area. Below are the maximum temperatures where the outside sensor recorded a peak feels like temperature of 92°F. To normalize the recorded sensor temperatures to the ASHRAE 0.4% design day conditions 3°F was added. All-in-all, significant temperature drops throughout this gypsum board plant thanks to the new ventilation solution.