Static Pressure

Whether performing an installation in a new construction home or a system change-out on a 50 year old home, knowing the static pressure on your duct system may give early detection of problems that may not present themselves for several years.

Measuring static pressure gives a solid indication of the volume of air being moved throughout the system. Most residential systems are designed to operate within .5 inches of water column.

To measure the static pressure in your duct, you must have either a digital or magnahelic manometer.

  1. Drill a small hole in the return ductwork on the blower side of the filter (after the filter)
  2. Drill a small hole in the supply ductwork close to the unit
  3. Insert tubing from the manometer (+ on the supply side, – on the return side) and turn the thermostat to “fan on”
  4. If the return measures -.25 and the supply measures +. 25, the static on the system would be .5 inches of water column.

If the numbers show anything higher than the manufacturers recommended ratings, check the sizing of the ductwork (both return and supply), and the filter to verify that the system can handle the rated pressure drop.

Jeff Rosenblum
Technical Support
16 Years Industry Experience
Cell (330) 962-2491
jrosenblum@famous-supply.com

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