No Loss Stackhead
No loss stacks reduce air flow resistance and save money!
More and more engineers are conscious of the need to conserve every aspect of energy. One historic 'thief' of a fan's performance has been the back pressure created by the twist and turns of the exhaust from a fan. The ideal solution is to have a straight shot to atmosphere. But this often was not possible because of the need to keep rain water out of the fan. The No Loss Stack solves that problem.
Constructed as a duct that is attached to and exhaust into a second duct that is 1" larger in diameter, the larger duct allows the air to exhaust while allowing rain water to run down its inside walls and drop outside of the inner duct.
Typically, the second duct has a length that is four times the diameter (4 x d) of the inner pipe. It is attached to the inner pipe with brackets and often has a flange on the top lip in order to 'guy' wire the entire unit to the roof.
No-Loss Stacks or No-Loss Stackheads as they're sometimes called, eliminate the back pressure that causes increased fan resistance. Increased resistance causes the fan to use additional power to maintain the calculate cubic feet per minute (CFM) rate required for the system. To correct this, as you can see in the drawing below, the central exhaust duct is surrounded by the larger duct of the no-loss stack, and extends up higher than the central duct and is open at the bottom. Rain water then falls into the upper part of the larger duct and drains down the side of the no-loss stack and discharges at the bottom. No-Loss stacks are most often ordered in galvanized and stainless steel.
We make sure all of your size and transition needs are taken care of when you order a No-Loss stack for your system.
Download No-loss Stack Spec Sheet