Bypass Damper vs. Barometric Zone Damper

Bypass dampers are used in zoning applications to relieve excess system pressure caused when a small or single zone is making a heat or cool call. Excess pressure can occur when not all of the dampers are open. This excess pressure must go somewhere, which is why installing a bypass damper is necessary. It enables the excess pressure to be redirected back into the air system and re-circulated through the system.

 

There is no doubt that a zoning system requires a mechanism to relieve the built-up pressure. Until recently, installing a bypass damper was the only option available to do this.  While zoning is a great concept for increasing the comfort provided by an HVAC system, installing a bypass damper can present challenges such as no room for the installation, extra labor and materials required, and even decreased system efficiency. 

 

Ron Jackson, President of Jackson Systems and HVAC inventor and innovator, is all too familiar with the headaches contractors associate with installing bypass dampers. He wanted to figure out an easy to use solution to zoning applications.  As happens with many great inventors, Ron was awakened at 3AM. He said aloud, “Man, have I got an idea for a product that could change the zoning industry.” And the BZD was born.

 

The BZD damper works like any standard damper with one exception – it has a built-in barometric relief mechanism that eliminates the need for a bypass damper. Tests indicate that most systems can handle up to double the rated cfm through the registers before noise becomes a problem. Unlike a standard zone damper, the BZD has been designed with both a fixed and a hinged blade and is controlled by an actuator. The lower half of the blade then functions as a barometric pressure relief for the system. The Barometric Zone Damper will allow the barometric half of the closed zone damper to open if the static pressure reaches the preset setting and bleed a small amount of air into the zones that are not calling, keeping the system static pressure at an acceptable level. Tests also indicate that bleeding a small amount of conditioned air to the zone(s) that are not calling has little impact on the temperature in the zone(s) because in most cases they are above or below setpoint, so the zone(s) can absorb the additional conditioned air. The BZD damper is factory-set and should not need any adjustments.

 

The BZD is a contractor-friendly solution to the typical zoning installation problems. It works as well as a standard bypass damper, but cuts down on the labor and time, not to mention headaches. While bypass dampers are reliable options when there is room available for installing one, a BZD is a great solution when you run into problems installing a standard bypass damper. The next time this happens, you may find that the BZD is the perfect solution to ease your zoning installations. For more information on how the BZD works, click here.

 

Updated: October 16, 2012 — 9:38 am

1 Comment

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  1. Excellent explanation of a fairly complicated subject.

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