Static pressure is also known as system air resistance, and it is essentially a measure of the resistance to airflow that occurs in the HVAC system.
What is Static Pressure?
Static pressure is one of the most important factors in evaluating how your HVAC system works. It is a parameter that you should check frequently and understand at least at a basic level so that you can easily identify problems with your air conditioning.
The HVAC system’s static pressure is a measure of its airflow resistance throughout the heat pump, coil, filter, and ductwork. Just like your body, if the resistance to flow is high, the system should work harder in order to keep up. Working the unit harder could lead to premature failure. So, what’s the good news? You can avoid this with regular maintenance.
What Causes High and Low Static Pressure?
High static pressure is often caused by blockages in ducts, improper duct sizing, closed dampers, and kinked flex ducts while low static pressure is caused by leaking ductwork, separated duct connections, missing filters, or low fan speeds.
What Will An HVAC Contractor Do?
With the fan operating on the heat pump, the HVAC contractor will create a tiny hole in the return duct prior to the filter, and then another one in the supply ductwork following the evaporator coil. They will use a manometer to measure the difference in the pressure. The obtained measurement will be compared to the rating on the unit’s blower motor and ideally the static pressure should be . 82. In case the system is discovered to be operating beyond the recommended range, your HVAC contractor will discuss the options to fix the problem.