Savings Profile for Residential Ductless Heat Pump (Mini Split) Cleaning Measure

This project evaluates the energy efficiency (“EE”) and performance benefits of coil cleaning for ductless wall and floor mounted heat pumps, a routine maintenance practice that removes dust and debris from indoor and outdoor coils to maintain system performance. Unlike central heating, ventilation, and air conditioning (“HVAC”) systems, using ducted air handlers with higher-efficiency or Minimum Efficiency Reporting Value (“MERV”)-rated filters, most residential ductless heat pumps rely on low-efficiency washable mesh filters. These filters are primarily designed to protect system components rather than to achieve high particulate removal. Poor filtration, along with the configuration of ductless heat pumps (blower wheel downstream of the coil, putting the blower wheel below the dewpoint in cooling mode) makes ductless units more susceptible to blower wheel and coil fouling over time. Accumulated debris can restrict airflow, reduce heat transfer, and increase energy consumption.This project evaluates the before and after performance of ductless heat pump systems which receive professional coil cleaning, focusing on changes in system capacity, indoor air quality (“IAQ”), and overall performance. The working hypothesis is that regular coil cleaning can restore lost capacity in systems with moderate to severe fouling. Under typical operating conditions, this regained capacity may improve system performance and the coefficient of performance (“COP”). However, VEIC has not yet evaluated whether these capacity improvements translate into seasonal energy savings. Any potential reductions in kilowatt hour (“kWh”) consumption during heating and cooling seasons remain to be confirmed through additional data collection.This project addresses key market barriers, including low awareness of the benefits of coil cleaning and the lack of a dedicated EE measure for ductless systems. It also positions coil cleaning as a low-cost entry point into broader HVAC maintenance, potentially uncovering issues such as refrigerant leaks.Research will be conducted in at least 30 single-family and/or multifamily homes (the “Participant(s)”) to explore residential market dynamics and adoption barriers. This project will also consider how to ensure participation from households in disadvantaged communities (“DAC(s)”) and/or hard-to-reach populations (“HTR”). If DAC(s)/HTR participation is feasible, VEIC will examine whether there are differential benefits compared to non-DAC(s) households.Currently, limited field data are available on the frequency of coil cleaning. This project will reference presumed prevalence unless more robust data becomes available. The scope is intentionally focused on ductless systems, which differ from ducted systems in terms of filtration, airflow, and service requirements.Beyond energy savings, coil cleaning may offer important non-energy benefits, such as:Improved IAQ by reducing dust, allergens, and microbial growth on coils,Enhanced occupant health and comfort, particularly for individuals with respiratory conditions,Extended equipment life by preventing strain on system components caused by restricted airflow, orReduced maintenance costs over time by minimizing breakdowns and improving system reliability. Ultimately, this project aims to demonstrate that routine coil cleaning can reduce energy consumption, lower peak demand, and improve IAQ, especially in underserved communities. Findings will support utility programs, inform policy, and advance California’s goals around electrification, load flexibility, and equitable access to EE.