All saunas take resources to build and all use energy to produce heat. Some of them also use water. How much of each will determine which sauna has the greatest environmental impact.
In this article, we’ll help you find the particular type of sauna that’s the most energy-efficient and least impactful on the environment for your particular circumstance.
Assessment Criteria
In this assessment of saunas’ environmental impact we’re going to look at four of the typical sauna options (traditional, infrared, steam and electric) and consider the following factors:
- Type of energy source – Saunas are typically heated by electricity, gas, or firewood. Each of those options have varying impacts on the environment. In terms of carbon emissions, electricity generation can either be on one end of the scale from dirty (generated by coal-powered power plants) or clean (solar panels mounted on roof of house). If heating with wood, there too there’s a wide spectrum from wood cut down from a clear-cut forest that was transported a long distance to dead wood gathered from one’s own land.
- Amount of energy – Then there’s the amount of energy required: a smaller sauna requires less energy to heat up than a large one. How is the heat used (e.g. infrared is more efficient since it heats the body directly whereas a traditional sauna heats the air).
- Type of construction materials – Lastly, is the materials used to make the sauna. What you’re looking for is something smaller so it requires the least amount of materials as possible. And it should be made from the most sustainable materials possible (in this case, it would typically be wood).
- Amount of construction materials – The smaller the sauna, the less of the Earth’s resources it uses to be built.
- How well constructed – A sauna built with sufficient insulation will keep the heat in a lot better than a sauna without insulation, thus requiring less energy to heat.
- Construction method vs transportation – The distance the materials travel to build the sauna have an impact on whether it’s an eco-friendly option or not. There’s a spectrum here from the most locally sourced option (DIY construction of wood sauna using wood locally sourced) to having a fabricated unit shipped from Asia that contains multiple parts, each of which was shipped from other parts of the world to make it.
- Deconstruction – How will the unit be disposed of at the end of its useful life? Concrete is not biodegradable whereas wood is. Metal can be recycled easily and more economically than concrete.
- Water usage – Another important resource to consider is water. Does the sauna use water or not? If so, how much does it use?
1. Traditional Outdoor Sauna
A traditional outdoor sauna is like a little cabin in the woods. There’s a serenity that comes from the combination of being in nature, enclosed in a wood cabin that’s powered by a wood fire. You can enjoy the calming effect of looking at some greenery while you relax and take in fresh air walking to and from the sauna. And because there’s no need for electricity, an outdoor sauna can be powered off-grid from your own wood source.
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However, there are also some drawbacks to consider when opting for a traditional sauna. One is that you’ll need to build a fire to heat the sauna, which can be time-consuming and produce smoke, and you’ll need a source of firewood. Wood burning can also be worse for the environment than by generating heat via electricity.
How They Are Made
Traditional outdoor saunas are made from wood, such as cedar, spruce or redwood. They use a wood-burning stove for heat and commonly have a water barrel for moisture. There are often rocks placed on top of the stove for heat storage as well as to create steam from pouring water on top.
What’s the Environmental Impact?
Wood burning comes with quite some serious environmental impact.
There’s debate surrounding this topic because trees decompose over time, which releases CO2. So on the one hand it’s believed that burning them is ultimately no different, it just speeds up the process. But that speeding up of the process is an issue since it can take 50 years for a tree to reach maturity, whereas we’re in a climate crisis now so we’d be better off to keep those trees in the ground as carbon sinks rather than burning them.
There’s a line of thought that burning wood is a better option than gas or electricity if you live rurally and have a local source of sustainably harvested wood. Finding local and sustainable are no doubt better than burning old growth or clear-cut forests as less energy is spent transporting the logs and the forests are planted to be cut down and regrown.
So if you’ve got those down you’re going to achieve much more sustainable combustion – particularly if you’re sourcing wood directly from your land. And bonus points if you’re gathering fallen branches and dead trees from your own land since they are already decomposing.
If you’re living rurally, it makes more sense to burn wood than in a city because many of the pollutants wood burning releases (e.g. nitrogen oxide, methane, and VOCs) cause air pollution, which is much more of a problem in the city.
In terms of carbon emissions, there’s room for debate here. Studies have shown that wood burning can release more CO2 than natural gas and even more than coal. However, the actual numbers would depend on where those fuels are transported from, the refining process and how efficient the heaters are that burn the fuel. Just about no one has a source of natural gas and coal on their property, though many people have a source of firewood. And that firewood does not need to be refined. There is, however, quite a range in efficiency among different models of wood-burning stoves.
Aside from emissions water usage is another factor. Since it’s common to use water to add steam to a sauna, there’s some additional impact on the environment from the water you use. That usage can be mitigated if you make an attempt to conserve water or if you have a sustainable source of water such as a rainwater catchment system.
2. Infrared Sauna
An infrared sauna uses infrared light to heat the body directly, rather than heating the air around you. Though they use a significant amount of electricity, their design makes them relatively efficient and much quicker to heat up than traditional saunas, taking only 10-20 minutes to heat up.
There are a few things to consider before investing in an infrared sauna. One is that they can be quite small, so if you’re tall or large, you may find them uncomfortable. Another thing to keep in mind is that because they heat the body directly, they can also be quite intense and may not be suitable for everyone.
There are two types of infrared: near infrared and far infrared. Near infrared emits shorter wavelengths, which causes them to penetrate the skin more deeply, reaching tissues and muscles, whereas far-infrared light goes less deep, mostly just affecting the surface of the skin, primarily affecting the surface of the skin. This results in near infrared feeling hotter because it penetrates deeper.
How They Are Made
Infrared saunas come in different types of enclosures from a small room akin to that of a traditional sauna to portable models that have collapsible frames to the most portable option, which is like a sleeping bag with heaters.
They generally use carbon fibre or ceramic heaters (or a combination of both) that produce infrared waves. The heaters are placed in strategic positions around the sauna so that the user’s body is evenly heated. Also, the saunas have a control panel that allows the user to adjust the temperature and time.
Environmental Impact
Infrared saunas use less energy than traditional saunas because they heat the body directly instead of heating the air around the body, making them rather efficient.
They run on electricity, so their impact is ultimately dependent on your energy source. If you power your home with renewable energy, this could be a green choice, particularly if you were to use your sauna on a sunny day while your solar panels are generating electricity. If your home is powered from the grid, the sauna’s carbon footprint will be greater as it would depend on the source of electricity generation that your provider uses.
Of the two types of infrared saunas, a far infrared sauna is more energy-efficient since it operates at lower temperatures than near infrared.
Once you know the particular type of sauna you want, you can then search the individual models you’re considering to see how much energy they actually use and what they’re made of as there’s quite some variation among each model.
3. Steam Sauna
A steam sauna or steam room is a type of sauna that uses steam to heat the air. They do not heat up as much as traditional saunas (40° to 50° C instead of 70° to 100° C) but they still feel hot because of the moisture.
One issue is that they require a considerable amount of water. Another consideration is that because they use steam, they are extremely humid (100% humidity), which some people could be sensitive to.
How They Are Made
Steam saunas are framed with wood, concrete or metal but instead of having wood lining the inside, they use a moisture-resistant material such as tile or stone. A steam generator is used to produce steam. Steam generators use electricity, gas or solar energy to heat up a water storage tank and then release that hot water as steam. A system of ventilation is needed to evacuate excess moisture and maintain air quality.
Environmental Impact
Steam saunas use electricity, gas, or solar thermal to heat the water that is then converted to steam. For electricity their emissions depend on the fuel source used by the utility to generate the electricity (unless you are powering it via solar panels in your home). For natural gas a lot of the emissions has to do with the refining process. In both those cases, the transmission and distribution process plays a big part as well because the distance they have to travel, the mode of transmission, etc. is quite impactful.
Generating heat from solar thermal reduces the emissions impact of a sauna considerably since it’s a renewable resource that is generated right at home. However, solar thermal still requires electricity to power the system.
In terms of water consumption, the amount of water that steam saunas take make this option more water-intensive than other types of saunas.
4. Electric Sauna
Similar to a traditional outdoor sauna, an electric sauna is a type of sauna that uses electricity to heat the air. They require a lot of electricity, which can be costly to operate and produce significant emissions and pollutants, dependent on your energy source as previously mentioned.
How They Are Made
Electric saunas use electric heaters that are controlled by a thermostat. The heater warms up the rocks or metal grating that is placed over it, and the heat radiates out from there.
Environmental Impact
The main environmental concern with electric saunas is the amount of energy they use. If you’re using an electric sauna that’s not very well insulated, a lot of heat will escape and get wasted, causing you to use more energy to heat up the sauna.
Also, electric saunas pose a high fire risk due to their combination of the electric heater and wood walls. So if you’re not careful to avoid doing things like putting flammable objects on the coals or drying your towel on the stove guards, you could start a fire.
The Verdict
Given how many factors go into choosing a sauna with the lowest environmental footprint, it’s not as simple to say one type of sauna is better than another and leave it at that.
Nonetheless, if you use solar panels to power a far infrared sauna and that sauna is built efficiently you’ll have the lowest environmental impact due to the combination of their smaller size (and in some cases very minimal construction – e.g. collapsible frames or sleeping bag type of portable saunas) paired with the clean energy generation from your rooftop.
Feature image: HUUM; Image 1: Max Vakhtbovych
