Minimally. The fan runs continuously and uses about 50-90 watts, roughly $5-$10 per month in electricity. Heated/cooled air loss through the system is offset by sealing work done during install.
More detail
The math: a Radonaway RP145 fan at 80 watts running 24/7 consumes about 700 kWh/year, costing roughly $95-$110/year on AEP Ohio residential rates. The conditioned-air loss through the radon stack is typically a wash because the install includes sealing slab cracks, sump pits, and rim-joist penetrations that were leaking conditioned air into the soil before mitigation. In practice, blower-door tests pre and post often show a slight reduction in air-change rate after mitigation due to the sealing work. For homes with combustion appliances (gas furnace, water heater, gas dryer on Columbia Gas of Ohio service), proper mitigation design includes makeup-air consideration; back-drafting is preventable but worth confirming with a combustion-safety test if the home uses natural-draft appliances. Columbus AEP Ohio residential rate context: at roughly $0.14/kWh average and 700 kWh/year fan consumption, the annual electric cost runs $95-$110. Time-of-use plans (off-peak overnight charging) do not affect this materially because the fan runs continuously. Solar-equipped Columbus homes effectively offset the full radon-fan electric cost; battery-backed solar covers it during outages too. For homeowners tracking energy use closely, the radon fan is a fixed continuous load that shows up cleanly on smart-meter usage breakdowns and can be verified at install time using a Kill A Watt meter or equivalent.