1. How Much Power Does a Radon Fan Use?
Most residential radon fans draw between 30 and 150 watts of power. The exact wattage depends on the fan model, size, and the resistance it faces from the sub-slab material. The most commonly installed fans in Georgia homes typically draw between 50 and 90 watts.
To put this in perspective, a 70-watt radon fan uses about the same power as a standard incandescent light bulb. The difference is that the radon fan runs 24 hours a day, 365 days a year, while you hopefully turn your lights off at night.
The wattage a fan draws depends partly on the sub-slab conditions beneath your home. If the material under your slab is loose gravel that allows air to flow easily, the fan does not have to work very hard and draws less power. If the material is tight clay or compacted fill, the fan has to work harder to create adequate suction, drawing more power.
Your radon professional selects the appropriate fan based on the conditions in your home. A properly sized fan provides adequate depressurization without being oversized and wasting energy. Learn more about professional radon mitigation and system design.
2. What Does It Cost Per Month?
The monthly electricity cost of running a radon fan is straightforward to calculate. Multiply the fan's wattage by 24 hours, then by 30 days, divide by 1,000 to get kilowatt-hours, and multiply by your electricity rate.
Low-Power Fan (30 watts)
30W x 24hrs x 30 days = 21.6 kWh per month. At $0.13/kWh (Georgia average), that is about $2.80 per month or $34 per year.
Typical Fan (70 watts)
70W x 24hrs x 30 days = 50.4 kWh per month. At $0.13/kWh, that is about $6.55 per month or $79 per year. This is the most common range for Georgia homes.
High-Power Fan (150 watts)
150W x 24hrs x 30 days = 108 kWh per month. At $0.13/kWh, that is about $14.04 per month or $168 per year. These larger fans are used in homes with tight sub-slab conditions or large foundation areas.
3. Different Fan Types and Their Wattage
Radon fans come in several sizes designed for different applications. The fan your system uses depends on the sub-slab conditions, foundation size, and how much suction is needed to achieve effective depressurization.
Low-Suction Fans (20 to 50 watts)
Used in homes with very permeable sub-slab material (clean gravel). These fans do not need to work hard because air flows easily beneath the slab. Lowest operating cost and quietest operation.
Medium-Suction Fans (50 to 90 watts)
The most commonly installed type. Suitable for the majority of Georgia homes with mixed sub-slab conditions. Provides good depressurization at reasonable energy cost.
High-Suction Fans (90 to 150 watts)
Used when sub-slab material is tight (clay, compacted fill) or when the foundation area is large. These fans create more vacuum to pull through resistant material.
Multi-Suction Point Systems
Some homes need multiple suction points with separate fans. The total power consumption is the sum of all fans. However, a well-designed multi-point system may use smaller fans at each point, keeping total consumption reasonable.
4. Compared to Other Appliances
To put radon fan energy use in perspective, here is how it compares to other things running in your home.
A typical radon fan at 70 watts uses about 50 kWh per month. Your refrigerator uses about 30 to 50 kWh per month. A dehumidifier uses about 30 to 50 kWh per month. A ceiling fan running 12 hours a day uses about 20 to 30 kWh per month. Your dryer uses about 30 to 50 kWh per month (depending on how often you run it).
In the context of a typical Georgia home's total electricity consumption of 1,000 to 1,500 kWh per month, a radon fan adds about 3 to 5 percent to your total usage. During summer months when AC is running heavily and your total bill is higher, the percentage is even smaller.
Bottom Line
Running a radon fan costs about the same as leaving a porch light on all the time. It is one of the most affordable continuous-protection systems you can have in your home, especially compared to the health risk it eliminates. See our radon mitigation cost guide for a full breakdown of system costs.
5. Can You Reduce the Energy Cost?
While the energy cost of a radon fan is already quite low, there are a few things worth knowing.
First, never turn your fan off or put it on a timer. The savings would be minimal (a few dollars per month at most) and the health risk is real. Radon can accumulate to dangerous levels within hours of the fan being turned off.
Second, if your fan is old and you are replacing it, newer fan models tend to be more energy-efficient. A replacement fan may draw less power while providing the same or better suction. Our radon fan repair services can help you choose an efficient replacement when your fan reaches the end of its life.
Third, sealing major cracks and gaps in your slab can improve your system's efficiency. When the fan has fewer air leaks to compete with, it can maintain the same depressurization with less effort. This does not reduce the fan's wattage, but it does improve the overall efficiency of the system.
6. Is the Energy Cost Worth It?
This is an easy question to answer. A radon mitigation system that costs $6 to $8 per month to operate is protecting your family from radon, the leading cause of lung cancer among non-smokers. The EPA estimates that radon causes about 21,000 lung cancer deaths per year in the United States.
For less than the cost of a monthly streaming subscription, your radon fan runs quietly 24/7, continuously drawing radon from beneath your home and venting it safely above the roofline. You do not have to think about it, maintain it frequently, or do anything other than check the manometer occasionally and pay a barely noticeable addition to your electric bill. For a complete care checklist, see our radon system maintenance guide.
When homeowners ask about the ongoing cost of their radon system, the energy bill is really the only recurring cost. There are no filters to replace, no chemicals to buy, and no regular service visits required. Fans typically last 10 years or more before needing replacement.
