The main environmental cost of a sauna is energy use, with traditional electric models consuming far more per session than infrared ones. You can reduce the impact by choosing an efficient sauna type, insulating it well, heating only to the temperature you need, and powering it with renewable energy where possible.
You're the kind of guy who thinks about the bigger picture. You want the health benefits—better circulation, stress reduction, maybe some heat shock protein activation—but you don't want to feel guilty about the energy bill or the carbon footprint every time you step into the heat. Fair question. Let's break it down.
The Real Environmental Cost of a Sauna Session
Most sauna environmental impact comes down to one thing: energy use. A traditional Finnish sauna with a wood-burning stove uses about 15 to 25 kilowatt-hours of electricity per session if it's electric, or roughly 6 to 10 pounds of wood if it's wood-fired. An infrared sauna typically uses 1.5 to 3 kilowatt-hours per session, depending on size and how long you stay in.
To put that in perspective: a 20-minute electric sauna session at 185°F uses roughly the same electricity as running a clothes dryer for an hour. Do that four times a week, and you're looking at about 50 to 100 kilowatt-hours per month just for sauna use.
The second environmental factor is materials. Traditional saunas are built from cedar, hemlock, or spruce. If those woods come from sustainably managed forests, the impact is manageable. If they're clear-cut from old-growth forests, that's a different story. Infrared saunas often use manufactured wood products, adhesives, and electrical components that have their own manufacturing footprint.
Then there's water. If you're pouring water on hot rocks (löyly in Finnish), you're using maybe a quart per session. That's negligible. But if you're showering before and after—which you should—that water use adds up.
How to Make Your Sauna Routine More Eco-Friendly
1. Choose the Right Type of Sauna
If you're buying or building, the most eco-friendly option is a wood-fired sauna using locally sourced, sustainably harvested wood. The heat source is renewable, the carbon footprint of production is low, and when the sauna eventually needs replacement, the materials biodegrade.
If wood isn't practical—apartment living, no outdoor space—an infrared sauna is your next best bet. It uses roughly one-tenth the energy of a traditional electric sauna because it heats your body directly rather than heating the air. A 2021 study in the journal Energy and Buildings found that infrared saunas consumed 80% less energy than conventional electric saunas for equivalent physiological effects.
Traditional electric saunas are the least efficient. They heat the entire room to high temperatures and lose significant heat through walls, ceiling, and the door.
2. Insulate Like You Mean It
Most sauna heat loss happens through the ceiling and walls. If you're building or retrofitting, use proper insulation behind the sauna walls. Mineral wool or fiberglass batts with an R-value of at least R-13 for walls and R-19 for ceilings will keep the heat inside where it belongs. A well-insulated sauna heats up faster and holds heat longer, meaning less energy per session.
Also check the door seal. If you can feel a draft, you're losing heat. A magnetic seal or a tight-fitting wooden door with a drop-down threshold can cut heat loss by 15 to 20%.
3. Timer and Preheating Strategy
Most people overheat their sauna. You don't need the room at 200°F to get the benefits. Research on heat shock protein activation and cardiovascular effects shows benefits starting at around 150°F to 175°F. Each degree above that costs more energy.
Set a timer. Don't let the sauna run for an hour before you step in. Most electric saunas reach temperature in 20 to 30 minutes. Preheating for 45 minutes wastes energy.
If you're using a wood-fired sauna, you can't exactly "set a timer," but you can be strategic. Build a smaller fire. The goal is hot rocks, not a roaring inferno. Finnish sauna tradition actually favors a longer, slower heat-up with smaller wood splits. It's more efficient and produces a gentler, more pleasant heat.
4. Use Renewable Energy
If your sauna is electric, check your energy provider for renewable options. Many utilities now offer green power plans where your electricity is matched by wind or solar credits. If you own your home, solar panels on the roof can offset sauna energy use entirely. A typical sauna session uses about the same energy as running a refrigerator for six hours. One or two solar panels can cover that.
5. Reduce Water Waste
The post-sauna cold shower is part of the ritual, but you can make it smarter. Install a low-flow showerhead. Keep the shower short—two to three minutes is enough to cool down and rinse off. If you're at a gym or public sauna, skip the long hot shower afterward. A quick rinse is all you need.
6. Maintain Your Sauna
A sauna with a broken thermostat runs hotter than necessary. A stove with a clogged flue burns less efficiently. Cracked rocks can't hold heat properly. Basic maintenance—cleaning the stove, replacing worn-out rocks, checking thermostat accuracy—keeps your sauna running at peak efficiency.
For wood-fired saunas, burn only seasoned, dry wood. Wet wood produces less heat per pound and more smoke. Seasoned wood (dried for at least six months) has about 20% more usable heat energy per pound than fresh-cut wood.
The Carbon Footprint Math
Let's run some rough numbers so you can see where you land.
- Electric traditional sauna, 4 sessions per week: About 400 to 600 pounds of CO2 per year, depending on your local grid mix.
- Infrared sauna, 4 sessions per week: About 60 to 100 pounds of CO2 per year.
- Wood-fired sauna, 4 sessions per week: Carbon neutral if the wood is sustainably harvested (the carbon released was absorbed during the tree's growth). Not neutral if the wood is trucked long distances or harvested unsustainably.
For comparison: a typical American household's annual carbon footprint is about 48,000 pounds. A sauna session represents a fraction of a percent of that total. But if you're already optimizing your home energy use, every bit counts.
The Bigger Picture
Here's the thing nobody talks about: a sauna might actually reduce your overall environmental impact in indirect ways. Regular sauna use is associated with better cardiovascular health, lower stress, and improved sleep. Healthier people use fewer medical resources. They miss fewer work days. They live longer, more active lives. There's an argument that the health benefits of sauna—reduced inflammation, better circulation, lower blood pressure—more than offset the energy cost.
I'm not saying you should sauna for the planet. I'm saying don't beat yourself up about the energy use. A 20-minute sauna session twice a week is not the problem. The 30-minute commute in a gas car, the plastic packaging on your groceries, the air conditioning you run all summer—those are the numbers worth worrying about.
If you want to be thoughtful about it, choose an efficient sauna, insulate well, heat it only as hot as you need, and use renewable energy if you can. That's good enough.
Practical takeaway: If you currently use an electric traditional sauna four times a week, switching to an infrared model would save you roughly 300 to 500 pounds of CO2 per year. That's the equivalent of not driving about 500 miles. Not nothing. Not everything. But a real, measurable improvement.
Frequently asked questions
How much energy does a sauna use per session?
A traditional electric sauna uses about 15 to 25 kilowatt-hours per session, while an infrared sauna typically uses 1.5 to 3 kilowatt-hours depending on size and session length. A wood-fired sauna burns roughly 6 to 10 pounds of wood per session. Infrared models use considerably less energy because they heat your body directly rather than heating the entire room.
Is an infrared sauna more eco-friendly than a traditional sauna?
Yes, infrared saunas are significantly more energy-efficient than traditional electric models. A 2021 study in the journal Energy and Buildings found that infrared saunas consumed 80% less energy than conventional electric saunas for equivalent physiological effects. If you use an electric traditional sauna four times a week, switching to infrared could save roughly 300 to 500 pounds of CO2 per year.
What's the most eco-friendly type of sauna?
A wood-fired sauna using locally sourced, sustainably harvested wood is considered the most eco-friendly option. When the wood comes from sustainably managed forests, the carbon released during burning was already absorbed during the tree's growth, making it effectively carbon neutral. Traditional electric saunas are the least efficient because they heat the entire room and lose significant heat through walls, ceiling, and the door.
How can I reduce my sauna's energy use without buying a new one?
Proper insulation behind the sauna walls and a tight door seal are among the most effective steps, since most heat loss happens through the ceiling and walls. You should also avoid overheating the room, as research cited in the article shows heat benefits starting at around 150°F to 175°F. Setting a timer and not preheating for longer than necessary also helps, since most electric saunas reach temperature in 20 to 30 minutes.