If  it’s a little hard to grab the concept of static pressure think of measuring that pressure in your -HVAC system in terms of the doctor measuring your blood pressure. A blood pressure reading gives the doctor a good indication of your overall health. The same is true of a static pressure reading. lt will give the HVAC technician an idea of our system's general health.

 

As a matter of fact there is a quick way to determine if the static pressure reading the HVAC technician takes is good or not lets say the fan in the heating and cooling system is rated at "0.5" of water column" This figure can be easily obtained by the technician. The 0.5'reading would correspond to a 120/80 or perfect, blood pressure reading.

 

If the reading on the HVAC system comes in at "10" of water column" that means there is too much air flow restriction pressure in the unit by a factor of 2. Multiplying both blood pressure figures by 2 gives a corresponding reading of 240/160. This is much too high for a blood pressure reading and also for any HVAC system. Anyone can easily understand this number!

 

If the reading is "0.75' of water column" that's 1.5 times normal pressure. This would give a corresponding blood pressure reading of 180/120.This figure is still too high.

 

The figures shown using these examples can give the facility manager an easy way to compare and understand what the static pressure in their HVAC system is.If the static pressure in the HVAC system is too high then the system is not going to operate as well as it should. Just like a person’s body.