A 10-minute shower, at 5 gallons per minute, will use around 22,000 btu of energy (about 6 kilowatts) for the hot water. If you’re using a low-flow showerhead you might reduce that to 2.5 gallons per minute using 11,000 btu (3 kilowatts). After the shower you’ll have cleaned up the surface of your skin, but I find even a 10 minute shower doesn’t get me that warmed up and I start to feel cold as soon as I get out of the water. You can have two or more people shower together and save on hot water, but except in sexy movie scenes, most people shower alone most of the time.
A typical sauna session for us will last about 4 hours and use 200,000 btu of propane. During and after a sweat we’ll have cold showers. Typically we can sweat up 10 or more people in an hour so in those 4 hours we can get 40 people cleaned up. That works out to about 5000 btu per person (about 1.5 kilowatts). It’s a nice deep clean from the inside out, and since the sauna builds up your internal heat, even with a post sauna cold shower you will be hot and likely still sweating for 10 minutes to an hour after you finish the sauna.
Now if you are one of those people who goes home and has a long hot shower after a long hot sauna you’re throwing off this whole calculation. Our numbers show you can get deep clean by having a sweat with 10 of your friends and feel toasty and relaxed for 1-2 hours for the low cost of 5000 btu per person, or lightly rinse your skin in 10 minute hot shower, all alone, while burning 20,000 btu. Saunas use one quarter of the energy of that personal shower while rewarding you socially, cleaning you better, relaxing you deeper and it’s way more fun.
Depending on where you shower, and what kind of sauna you have, the energy you use might come from wood, coal or gas, or maybe from hydroelectric or nuclear power. Your choice: pollute the air, destroy the ground, disrupt ecosystems, destabilize countries. Regardless of the source, more energy use is inherently more destructive and ultimately releases more pollutants into the atmosphere. Make the efficient choice and sauna with your friends. For your health. For your community. For national security. For humanity. For the planet.
This dilemma I’ve presented is admittedly reductionistic; you do have more choices. A 5-minute shower with a low-flow shower head will equalize the shower side of the equation; better yet the same 5-minute shower with a friend and you’re winning the green ribbon. But who wants to spend 5 minutes trading places under a warm sprinkle in a cold room, when you could be relaxing on a hot bench in good company? We think the choice is clear.
