Reducing HVAC Energy Costs: Tips for Air Handler Coils

 

Reducing HVAC Energy Costs: Tips for Air Handler Coils

By Hilary Nardone, Senior Permitting Manager 
Certified ASSE 12080  Legionella Water Safety and Management Specialist 
 

As energy costs continue to be historically high, there are numerous ways in which routine air handler coil maintenance can impact a facility’s bottom line.  By cleaning air handler coils routinely, Facility Departments will not only reduce energy spending, but they will also impact the energy efficiency of their systems. 

Regular coil cleanings have a financial impact on a facility’s water and electrical bills.  A study conducted by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 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” in a year (1).  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” (2).  

The U.S. Department of Energy reports that energy efficiency is one of the easiest ways to reduce energy costs (3).  Routine coil cleanings improve the system’s overall energy efficiency, which ultimately result in additional savings.  The same ASHRAE study 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).  Figure 1 shows the difference in air flow before and after a coil cleaning.  By improving the energy efficiency of air handler coils, Facility Departments prolong the lifespan of each air handler system.

Figure 1.  Before and after average air flow readings of an air handler coil.  Prior to cleaning, the coil’s average air flow was 3,015 ft3/m.  After the cleaning, the coil’s average air flow increased to 7,628 ft3/m. 

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. Office of Energy Efficiency & Renewable Energy. Best Management Practice #10: Cooling Tower Management. U.S. Department of Energy. https://www.energy.gov/eere/femp/best-management-practice-10-cooling-tower-management. Accessed January 15, 2023.

3.     Office of Energy Efficiency & Renewable Energy. Energy Efficiency. U.S. Department of Energy. https://www.energy.gov/eere/energy-efficiency. January 15, 2023.

4. ANSI/ASHRAE.  (2019).  ANSI/ASHRAE Standard 62.1-2019: Ventilation for Acceptable Indoor Air Quality.  ANSI/ASHRAE.  ISSN 1041-2336.  https://ashrae.iwrapper.com/ASHRAE_PREVIEW_ONLY_STANDARDS/STD_62.1_2019.  Accessed January 15, 2023.

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