What are infrared saunas?
Saunas are small enclosures in which people can enjoy dry heat that opens their pores and relaxes their muscles. Because saunas typically reach temperatures above 175 degrees Fahrenheit (80 degrees Celsius), walls and furniture in saunas tend to be made of durable wood which – unlike metal or plastic – remains comfortably cool throughout use of the sauna.
Historically, saunas were heated by a wood fire underneath a pile of rocks. Now, other (safer) options are available for heating the saunas that do not pose the fire risk and suffocation risk that traditional heating methods do. Remember, heat is transferred from one place to another via three modes: convection (when hot liquids or gases rise to cooler areas), conduction (when a hot object comes in direct contact with a cooler object), and radiation (when an object releases energy as electromagnetic waves that are absorbed by other objects, increasing their energy and therefore heating them). Fire spreads heat by all three of these means. Infrared waves, on the other hand, are part of the electromagnetic spectrum of waves that people cannot see but can feel as heat by radiation.
By the way, the mention of radiation should not worry you. Infrared heating is not the ionizing radiation of gamma rays and x-rays that is powerful enough to change the makeup of atoms and molecules, but the kind of non-ionizing radiation that allows us to see (visible light waves), listen to the radio (radio waves), and heat objects by exciting their atoms and molecules into a higher energy state.
Why are infrared saunas so popular?
Saunas have historically relied on heating the air in the sauna, and then that hot air heats the people who use the sauna. Infrared heating can heat the air in the sauna like a conventional sauna, but can also directly heat the people using the sauna, potentially reducing energy requirements of an infrared sauna compared to a conventional sauna.
Infrared heating poses fewer risks than other methods of heating. Saunas that use classic wood-burning fires are both a fire risk when flames are not properly controlled and need to be vented to prevent dangerous fumes from filling the sauna and house. Saunas that use electric heating elements can also pose a fire risk if flammable materials come into contact with the heating element. Infrared heat sources
Smaller 1- and 2-person infrared saunas are often compatible with standard 120-volt/15 amp grounded outlets, making them easy to install without modification to the home’s electrical system. Larger saunas and non-infrared saunas tend to have higher wattage ratings that require modified outlets with higher voltage and/or amperage.
What will it cost to run an infrared sauna?
The cost to run a sauna depends on the wattage of the sauna, how much it is used, and how much electricity costs where it is used. To calculate monthly energy costs of any sauna (conventional or infrared), multiply the wattage of the sauna by the number of hours the sauna is on per month and the cost per kilowatt charged by the electric company. We can write this as:
Monthly cost = wattage (in kilowatts) × hours used per month × cost per kilowatt-hour used
In some cases, infrared saunas have lower wattage than similarly sized conventional saunas, especially for smaller saunas for one to two people. Whereas 1- to 2-person infrared saunas are often designed with wattages below 1.6 kW that can be used in a standard 110 volt/ 15 amp outlet, even the smallest traditional saunas tend to be 3.0-4.0 kW saunas that require modified electrical outlets similar to those used for washers and dryers. As we can see in the equation above, doubling (or tripling) the wattage of the sauna also doubles (or triples) the cost of use even when amount of time used and cost of electricity are the same.
Time to heat sauna
In some cases, a similarly-sized conventional sauna and infrared sauna might have the same wattage, but when the infrared sauna is used to directly heat bodies without first heating all of the air in the sauna, the hours used per month for an infrared sauna are likely to be lower than hours used per month for a conventional sauna. Infrared saunas tend to have heaters directing infrared waves directly at surfaces that come in contact with users (such as the floor and benches) as well as at users’ bodies rather than relying on a single source of heat as in a traditional sauna. Hence, an infrared sauna can be ready to use just 10 minutes after turning it on, whereas a traditional sauna usually needs at least 30 minutes and often an hour to heat to usable temperatures. For a user who wants to spend half an hour a day in their sauna, that means their infrared sauna would be on for 40 minutes a day, whereas their tradition sauna might be on for 90 minutes a day, more than doubling their energy costs.
Costs of electricity
The effect of doubling costs will be felt more by users where energy is expensive than where energy is relatively cheap. Electric companies charge per kilowatt hour (kWh). This price can be very low in places like Idaho that rely primarily on hydroelectric power, and very high in places like Hawaii that rely on imported crude oil. While average consumer prices across the United States range from 9 to 34 cents per kWh, the average is around $0.12 per kWh.
It is important to remember that if using an infrared sauna to directly heat the body rather than heating the air in the sauna first, the energy costs are reduced primarily by reducing the amount of time the heater is on. In a conventional sauna, users tend to leave the sauna on for 30 minutes to an hour prior to use to heat the air from ambient temperature to sauna temperature (typically 160 to 210 degrees Fahrenheit, roughly 70 to 100 degrees Celsius). Outdoor saunas used during winter months might be combating below-freezing temperatures and need to heat longer than that. Infrared saunas are more commonly used indoors and can effectively heat users in just 10 minutes. Hence, for the same price, a user of an infrared sauna can use their sauna twice as much as the user of a conventional sauna.
Example costs calculations
Let’s work out an example to estimate the cost of running an infrared sauna and a conventional sauna for one month. Let’s assume both saunas are rated as 6000-watt (W) saunas. As mentioned above, we usually talk about electricity usage in kilowatts (kW), so we should divide the wattage by 1000 to determine the sauna’s wattage in kilowatts. In our example, 6000 W divided by 1000 equals 6 kW.
The more that the sauna is used, the more that differences in cost to run one sauna versus another will add up. Using our example of the user who wants to enjoy half an hour a day in their sauna, we will calculate their energy costs for both an infrared and traditional sauna.
For the infrared sauna, the sauna will run for 40 minutes per day (10 minutes heating the sauna, 30 minutes using it). For a 30-day month, that is a total of 1200 minutes. Dividing 1200 minutes by 60 translates this to 20 hours. We multiply this time by the 6kW required by the sauna to get 120kWh used per month. At the average cost of energy, a consumer might expect to pay 0.12 dollars/kWh x 120 kWh = $14.40 per month to spend half an hour a day in the sauna.
For the traditional sauna, the sauna will run for 75 minutes per day (45 minutes heating the sauna, 30 minutes using it). For a 30-day month, that is a total of 2250 minutes. Dividing 2250 minutes by 60 translates this to 37.5 hours. We multiply this time by the 6kW required by the sauna to get 225kWh used per month. At the average cost of energy, a consumer might expect to pay 0.12 dollars/kWh x 225 kWh = $27.00 per month to spend half an hour a day in the sauna.
In a place where the energy costs are higher at $0.30 per kWh, the infrared sauna would cost $36.00 per month to use this way whereas a traditional sauna would cost $67.50. A lower wattage infrared sauna that is compatible with standard 110-volt outlets would cost less than a third of this price to use.
For many users, an infrared sauna is likely to be a good choice compared to a traditional sauna if they want to install their sauna indoors, use existing power outlets, and keep their energy use and energy costs low.