Improve Energy Efficiency: Coil Cleaning

Improve Energy Efficiency: Coil Cleaning

By Hilary Nardone, Environmental Group Training Manager
Certified ASSE 12080 Legionella Water Safety and Management Specialist

Air handler coils become fouled with dust, dirt, pollen, and other contaminants, which can all have an adverse effect on indoor air quality.  Moisture may build up around the coils and drain pans, becoming a breeding ground for bacteria and mold.   Along with potential public health concerns from bacteria and mold amplification, the debris and microbial growth buildup can hinder the coils’ ability to function effectively.  Cleaning air handler coils is therefore critical for proper HVAC operations and maintenance.

Cleaning coils routinely improves their efficiency.  A study conducted by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) found significant increases in efficiency after coils were cleaned.  After cleaning half of the coils onsite, there was already a 25 percent increase in thermal efficiency with respect to its ability to transfer its energy to sensible loads (changes in temperature).  There was also a 10 percent increase in thermal efficiency with respect to its ability to transfer its energy to latent loads (changes in humidity), which helped solve elevated humidity levels that had been reported in certain interior locations prior to the cleaning [1]. Efficiently running air handler coils provide the proper air flow.  The U.S. Department of Energy reports that correct air flow achieves the desired balance between sensible and latent heat transfers [2].

Regular coil cleanings can have a financial impact, as well.  The same ASHRAE study found that cleaning one air handler (of four that were onsite) “resulted in improvements that will lead to energy savings of up to $40,000” 1 in a year.  Not only do dirty coils decrease efficiency, but they can also increase how much money a facility may spend on utilities.  For example, the Office of Energy Efficiency & Renewable Energy has stated that “as coils become dirty or fouled, there is increased load on the chilled water system to maintain conditioned air set point temperatures.  Increased load on the chilled water system not only has an associated increase in electrical consumption, but it also increases the load on the evaporative cooling process, which uses more water” [3].

Having a regular air handler coil maintenance schedule is recommended in ASHRAE Standard 61.2-2019.  Coils, along with associated drain pans and drain lines, should be visually inspected for biological growth at least annually as part of a comprehensive maintenance schedule for indoor ventilation equipment [4].

Barclay’s Environmental Group performs coil cleanings in accordance with the equipment manufacturer’s recommendations.  Our technicians are trained to wear the appropriate personal protective equipment and follow all safety precautions.  For all coil cleaning jobs, we provide a written report and before and after photographs and air flow readings to validate effectiveness.  Schedule your coil cleaning with us today!


[1] Montgomery RD, Baker R.  (2006).  Study verifies coil cleaning saves energy.  ASHRAE Journal (Vol. 48, 34-36).    ASHRAE.

[2] Springer D. and Dakin B.  (2013).  Measure Guideline: Air Conditioner Diagnostics, Maintenance, and Replacement.  U.S. Department of Energy: Energy, Efficiency & Renewable Energy.  Accessed February 21, 2022

[3] Office of Energy Efficiency & Renewable Energy.  Best Management Practice #10: Cooling Tower Management.  U.S. Department of Energy.  Accessed February 21, 2022.

[4] ANSI/ASHRAE.  (2019).  ANSI/ASHRAE Standard 62.1-2019: Ventilation for Acceptable Indoor Air Quality.  ANSI/ASHRAE.  ISSN 1041-2336.  Accessed February 22, 2022.

Contact Barclay Water Management, Inc.

Copyright © 2021, Barclay Water Management. All Rights Reserved.