static pressure and airflow

It’s important to keep HVAC equipment clean and free of built-up dirt and debris. Hygienic duct cleaning and the disinfection of system components are also key to achieving proper indoor air quality. While this step assists facilities managers in their efforts to maintain healthy IAQ for occupants, static pressure is another consideration.

Static pressure is used in the area of fluid mechanics. Put simply, it’s the resistance to airflow that occurs in HVAC ductwork and within the system itself. When static pressure is too high or low, this reveals a problem within the system. Identifying a problem allows managers to schedule repairs before a more serious problem occurs. It keeps the system running at peak performance which lowers operating costs. It also lengthens the lifespans of equipment.

Static Pressure and How It Affects HVAC Systems

From heating and cooling systems in the home to large HVAC units in commercial buildings, these systems all transport air. The ductwork also is the path for airflow in the system. The correct installation of these systems ensures proper operation. However, resistance to airflow degrades system efficiency. When static pressure builds, this restricts and even stops airflow. 

Issues of static pressure occur with the use of the wrong filter as well as the failure to replace dirty filters. Improper design is another factor. For example, if a return intake is too small, high static pressure results. Likewise, if the return intake is too big, low-pressure results. Either way, a correction must be made for optimal performance.

Recognizing a Problem

Static pressure is measured in inches of water column. For example, a fan rating of 0.5” of water column is considered the right amount of static pressure. If, however, that reading is 1.0″ of water column, that’s too much airflow restriction. Likewise, a reading of 0.75″ of water column is still above an acceptable level.

A sign of too much static pressure is loud operation. If the system too loud during normal operation this means the pressure is too high. Hot or cold air spots in the building indicate a problem as well. Too much pressure makes the system work longer to achieve the desired set point. As a consequence, parts wear out quicker which may lead to equipment failure. Poorly sealed ductwork also creates potential static pressure issues.

Maintaining the system through routine inspections and cleaning improves IAQ which in turn leads to happier, more productive workers for a better bottom line.

Maintaining HVAC Systems

Achieving optimal IAQ and system performance requires a multi-faced approach. Pure Air Control Services provides several methods designed to keep systems in top condition. This translates to minimizing static pressure and other issues that affect the delivery of clean, fresh air to building occupants.

Assessing Static Pressure on the HVAC System

Maintaining the correct static pressure in an HVAC system is critical. For example, an HVAC Hygiene Assessment gives facilities managers a precise indication of the impact of the system on IAQ. This includes a visual inspection for the cleanliness of coils, drain pan, blower, and ductwork. Samples from the AHU undergo testing at an environmental lab. Performance testing also helps gauge the impact of static pressure across the fan and coils. The resulting report gives managers the information needed to make corrective action. 

Additional testing and analysis can include assessments for the following:

  • Airflow
  • Air filtration
  • Energy usage
  • Building pressure
  • Building envelope tightness

Remediation Sciences to Improve System Efficiency

The suite of remediation methods provided by Pure Air Control Services includes the cleaning, disinfection and restoration of the HVAC system.


This cleaning method restores the system to near-factory specifications. The result is better performance, increased energy efficiency, and lower energy costs.


This method uses high-pressure air turbulence to get deep inside the system knocking out dirt and debris. Afterward, a vacuum system with HEPA filtration removes this material which improves airflow and creates ideal static pressure and healthier IAQ.


This method uses specialized equipment with EPA-registered disinfectants and to primarily disinfect occupied spaces. However, a modified version is employed for ductwork and HVAC components as well. It gets to areas that topical disinfectants can’t reach and is effective in neutralizing mold, bacteria, viruses, and other pathogens with no residue left behind.

HVAC New Life

The goal of our New Life method is the restoration of the HVAC system through the following methods:

  • PURE-Cell  — The insulation of zero-porosity, fiberglass-free material.
  • PURE-Coil — An application of corrosion-resistant siloxane coating.
  • PURE-Liner — The application of a low VOC coating to protect the drain pan.
  • PURE-Coat — Applies an anti-viral, anti-microbial coating to protect the AHU inside and out.

How Is the Static Pressure in Your System?

If you manage a healthcare facility, school, or commercial building and suspect a problem with static pressure, find out for sure. Contact Pure Air Control Services today and provide clean indoor air to staff, customers, students, patients, and visitors. Call 1-800-422-7873 today or email us here.