HVAC Static Pressure Guide

HVAC static pressure is airflow resistance in the ductwork, something that heating and cooling systems need to circulate air throughout a home. Let’s take a look at signs and causes of high static pressure.

What Is Static Pressure In HVAC?

Why does static pressure mean so much to homeowners? For starters, high static pressure can wreak havoc on the HVAC system. It can cause fans and blowers to work harder than they should. Once high static pressure is noticed, it’s crucial to correct this as soon as possible.

Signs Of High Static Pressure

High static pressure will result in persistent noise coming from your system. It may be just a bit louder than most homeowners are used to, but in some cases it can be quite noisy. This happens when airflow is met with resistance within the system. It will worsen as the system heats up. The noise you can hear may be coming from any part of the system.

Warm air carries contaminants more easily, which can cause air quality to ultimately decrease. This air carries more contaminants to the next room if it has to pass through a restricted pathway. The heat may then only blow out of one area of the room if there is high static pressure. This can create many cold spots throughout the home.

High static pressure can also result in higher energy costs. Your system will have to work much harder when dealing with high static pressure. Your energy bills will likely skyrocket at this time.

High Static Pressure Causes

Here are the three main causes of high static pressure.

Clogged Air Filter

A clogged filter will undoubtedly slow airflow. Static pressure will rise when the airflow begins to slow down. “Too restrictive” means your filters are too small within your system. It’s very important to use a properly sized filter to prevent this issue.

Dirty Indoor Coil

Air is either heated or cooled as it passes through the indoor coil. The coil is where static pressure begins to build. This happens mainly due to a dirty coil that has difficulty moving air.

This situation can get worse if the coil is either dirty or too restricted on top of producing a higher output than its return can accommodate.

Undersized Air Returns

Air returns in a room should be appropriately sized to match the system’s air output. This is generally measured in cubic feet per minute. If an undersized return is related to an oversized output, high static pressure will result.

This is a common problem, unfortunately. It can be resolved, though, by simply installing a return that better matches the system.

Conclusion

High static pressure can decrease the lifespan of your system. Higher workloads ultimately wear out the unit. For example, when blowers and fans work harder to push air, they may overheat and burn out. The compressor may also take on too much pressure at this time.

Always be wary of the static pressure in your system. High static pressure can lead to a lot of damage. Keep your return vent properly sized and clean your filter and coil regularly.