Published figures first. The calculator below is an estimate only. It does not guarantee savings.
The U.S. Department of Energy: a dirty condenser coil can increase compressor energy consumption by 30 percent.
Source: U.S. DOE, quoted in Buildings magazine, “Clean HVAC System Coils Save Energy.”
Direct Supply’s published PTAC maintenance guide: dirty filters can decrease operating efficiency by as much as 20 percent. The same guide frames routine maintenance around 7 percent less energy use, or about $40–$50 per unit per year at their assumed rate.
Source: Direct Supply, “PTAC Maintenance Guide.”
A published analysis of four guestroom PTACs at Extended Stay America, Cypress Creek, Fort Lauderdale, measured cooling energy before and after professional coil cleaning. Combined cooling cost on those four rooms fell from $1,751 to $592 at $0.0678/kWh — about 68 percent on that test. Average supply airflow rose about 22 percent. One property in Florida, four rooms, one cooling-season snapshot.
Source: RPM Energy Consulting, September 2020. PDF hosted by Fibercare. We did not perform that test.
Illustration only — not a guaranteed rebate or payback. Efficiency falls as units run and collect dust; manufacturers recommend a deep clean twice a year. Change the inputs to match your property.