Background: Tension pneumothorax is a leading cause of preventable death in combat scenarios. When treating a chest wound with the potential for open hemopneumothorax using a chest seal, it is important that it efficiently drain fluid from the chest cavity. We tested the ability of commercial and novel chest seal designs to drain fluid from a simulated chest wound. Methods: Eight novel laminar chest seal designs were created and compared to six commercially available chest seals. Closed-cell foam with a hole was used to simulate a chest wound. Fluid pressures of 10, 30, and 100cmH2 O were tested. Mean flow rate through the chest seals was calculated. The percentage of the laminar channels completely saturated with fluid was also measured. The effect of laminar channel width and quantity on the dependent variables was determined. Results: Novel chest seals with the highest flow rates were comparable to commercial chest seals with the highest flow rates at all pressures. Channel saturations were also similar between novel and commercial chest seals. As the width of the laminar channels increased so too did flow rate (p=.048), while the percentage of channel saturation decreased (p=.006). As the quantity of channels increased, the flow rate tended to increase (p=.02), and percentage of channel saturation decreased (p=.03). Conclusions: Laminar vented chest seals with wider channel widths and more channels had higher flow rates and lower percentages of channel saturation. Certain novel chest seal designs used in this study were comparable to commercial designs in flow rate and percentage of channel saturation. © 2025, Breakaway Media LLC. All rights reserved.