A typical home oxygen concentrator draws between 300 and 600 watts while running, roughly comparable to a mid-sized refrigerator. The exact number depends on the unit’s capacity and what flow rate you’re using, but most people can expect their monthly electric bill to increase by $12 to $28 if the machine runs around the clock.
Power Draw by Concentrator Size
Oxygen concentrators come in two main sizes for home use, and the difference in power consumption between them is significant.
A 5-liter concentrator, the most commonly prescribed size, draws around 350 to 730 watts depending on the model and flow setting. These units deliver up to 5 liters per minute of oxygen and cover the needs of most people on supplemental oxygen therapy.
A 10-liter concentrator, used for higher-flow prescriptions, generally pulls over 1,000 watts. That’s closer to running a space heater full time. These larger units are less common but worth factoring into your budget if your prescription calls for one.
A good rule of thumb across all concentrators: power consumption should fall below 70 watts per liter per minute of oxygen delivered. So a machine set to 3 LPM should ideally draw under 210 watts, while one running at 5 LPM might pull up to 350 watts.
What Uses the Most Power Inside the Machine
An oxygen concentrator works by pulling in room air and filtering out the nitrogen, leaving concentrated oxygen. This process relies on a pressurized air compressor that accounts for 60 to 70 percent of the machine’s total electricity use. It’s the heart of the system and the reason these devices draw more power than most home medical equipment.
The remaining energy goes to cooling fans that run constantly to prevent overheating, electronic controls that manage the timing of pressurization cycles, and valves that direct airflow through the filtration beds. None of these components individually draw much power, but together they add a meaningful load on top of the compressor.
How Flow Rate Affects Your Electric Bill
Your prescribed flow rate, measured in liters per minute, directly controls how hard the compressor works. At a low setting like 1 or 2 LPM, the machine cycles less aggressively and draws noticeably less power. At the maximum rated flow, it runs near peak wattage continuously.
This means two people with the same model of concentrator can see very different electricity costs depending on their prescription. Someone using 2 LPM only at night will use a fraction of the electricity compared to someone running 5 LPM around the clock.
Estimated Monthly and Annual Costs
For a mid-range concentrator running 24 hours a day, expect your electricity bill to rise by roughly 29 percent over your current household average. In dollar terms, a study published in Scientific Reports calculated the annual electricity cost of running a concentrator continuously at about $144 to $333, depending on the unit’s wattage. That works out to roughly $12 to $28 per month.
These estimates are based on the national average electricity price from 2021, which was about $0.14 per kWh. If you live in a state with higher rates (California, Connecticut, Hawaii), your costs will run higher. If you’re in a low-rate state like Louisiana or Idaho, you’ll pay less.
To calculate your own cost, find the wattage listed on your concentrator’s label or manual, divide it by 1,000 to convert to kilowatts, then multiply by 24 (hours per day), then by 30 (days per month), then by your local electricity rate per kWh. For example, a 400-watt unit at $0.15 per kWh costs about $43 per month.
Portable Concentrators Use Far Less
Portable oxygen concentrators, the battery-powered units designed for travel, typically draw between 50 and 150 watts. They deliver oxygen in pulses rather than continuously, which is how they keep power consumption low enough to run on a rechargeable battery for several hours. Charging one from a wall outlet adds very little to your electricity bill, usually just a few dollars per month even with daily use.
The tradeoff is that portable units generally max out at 3 LPM and deliver pulse-dose oxygen, which isn’t suitable for everyone. Your prescription will specify whether continuous flow or pulse dose is appropriate.
Reducing Electricity Costs
You can’t lower the flow rate below what your doctor prescribed, but a few practical steps can keep costs manageable. First, check whether your utility company offers a medical baseline allowance or medical rate discount. Many states require utilities to provide reduced rates for households with life-sustaining medical equipment, and oxygen concentrators almost always qualify.
Keeping your concentrator’s intake filter clean also matters. A clogged filter forces the compressor to work harder, increasing power draw. Most manufacturers recommend cleaning or replacing the filter every two weeks. Placing the unit in a well-ventilated area away from walls helps the cooling fans work efficiently, which prevents the motor from overheating and cycling harder than necessary.
If you’re shopping for a new concentrator, compare the rated wattage across models with the same liter capacity. The difference between a 350-watt and a 600-watt 5-liter unit adds up to over $200 per year in electricity when running continuously.