HVAC Coil Testing Determines Amount of Fouling

HVAC coil testing is important to determine the amount of obstruction or level of fouling before cleaning. Measurement and verification (M&V) shows what areas of the coil need the most attention. It establishes a baseline for the amount of airflow passing through the coil. Tests taken after cleaning are then compared to the baseline. A simple calculation shows the percent of improvement. So, HVAC coil testing provides critical data to ensure a thorough cleaning. It also offers valuable insights on performance to building managers and owners. Let’s take a closer look at some HVAC coil testing methods.

Static Pressure Test

Testing the static pressure at each stage of the air handling unit (AHU) finds areas of resistance. A manometer and probe take pressure readings while the AHU is running. Simply put, airflow needs to be greater than resistance to circulate air in a building. When resistance is greater performance decreases. This leads to higher energy costs and indoor air quality issues. A static pressure test identifies components that contribute to resistance. These include defective dampers, filthy filters, clogged coils and more. It’s an effective HVAC coil testing method that is also a holistic picture of AHU performance

Coil Cleanliness Verification (CCV) Test

The CCV test specifically evaluates the resistance in the coil. This HVAC coil testing method happens when the AHU is off under lock out/tag out protocols. A handheld fan and flow gauge measure resistance in different zones on the supply side of the coil. Baseline airflow resistance gets logged by zone. Then a technician places color coded flags in each zone to mark the level of obstruction. This helps the cleaning technician concentrate on the most obstructed areas the coil. After the coil is cleaned the technician conducts another CCV test to verify improvements.

Two equations calculate the improvement in removing the obstruction. The first demonstrates the difference in pressure (resistance): Pa Before – Pa After = Delta P. For example, 18 Pa – 12 Pa = 6 Pa improvement. The second illustrates the percentage. In the case of the previous example it would look like this: 18 Pa – 12 Pa/18 Pa X 100 = 30%.

These HVAC coil testing methods supply data that show both performance issues and gains from cleaning. The data also provides visibility to building managers to act upon. For instance, performance reports help engineers calibrate control systems and energy consultants calculate credits. Most of all these tests verify the AHU’s operation is optimal after maintenance has been conducted.

PURE-Steam™ AHU/Coil Cleaning

PURE-Steam coil cleaning is a proprietary 14 step environmental cleaning process developed by the scientists at Pure Air Control Services. It uses high temperature and low pressure steam to deeply clean the coils. We include these valuable HVAC coil testing methods in every PURE-Steam project. The tests provide clear data to ensure a successful outcome each and every time.

For more information on HVAC coil testing or PURE-Steam please call 1-800-422-7873 or email us here.