A comfortable and secure sauna session depends on selecting the proper size sauna heater. The sauna room's size and the preferred temperature will determine the heater's size needed. Here are some important considerations to think about while choosing a sauna heater.
First, measure the volume of the sauna room in cubic feet. The general rule of thumb is to use 1 KW of power for every 50 cubic feet of space. So, for example, if your sauna room is 500 cubic feet, you would need a 10 KW heater. It is also essential to consider the desired temperature for your sauna. The higher the temperature, the more power the heater will need. For example, if you want a sauna temperature of 190°F, you will need a higher-powered heater than if you want a temperature of 150°F.
The type of sauna you have is another thing to think about. A different size heater is needed for an infrared sauna than a standard sauna. Infrared saunas heat the things in the room, such as the walls and benches, as opposed to conventional saunas, which heat the air. A smaller heater might be adequate because infrared saunas often use less energy to heat. Most of the health advantages of a sauna — including detox, muscle recovery, and improved blood circulation — have been proven in research using traditional dry heat saunas without infrared.
In summary, when choosing a sauna heater, consider the size of the room in cubic feet, the desired temperature, the type of sauna, and consult with a professional to ensure safe installation. Use 1 KW of power for every 50 cubic feet of space as a general rule of thumb.
Below is a general table that gives examples of correct heater sizing for different sized outdoor saunas.
| Sauna Room Size (Cubic Feet) | Recommended Heater Size (KW) |
|---|---|
| 50-250 | 2-5 |
| 251-500 | 6-10 |
| 501-750 | 11-15 |
| 751-1000 | 16-20 |
| 1001-1250 | 21-25 |
| 1251-1500 | 26-30 |
| 1501-2000 | 31-40 |
| 2001+ | 41+ |
Please note that this table is based on the general rule of thumb that 1 KW of power is needed for every 50 cubic feet of space. The desired temperature and type of sauna should also be considered when selecting a heater. It is always recommended to consult with a professional before making a final decision.
Outdoor & Uninsulated Sauna Considerations
If the sauna room is uninsulated and located outdoors, you will likely need a larger heater in order to maintain the desired temperature. The lack of insulation means that more heat will be lost through the walls, floor, and roof, requiring a stronger heater to compensate. The outdoor location also means that the sauna will be exposed to wind and other elements that can cool the room down faster.
As a general rule of thumb, you will likely need to increase the heater size by at least 25-30% to compensate for the lack of insulation. For example, if you would normally need a 10 KW heater for a 500 cubic feet indoor sauna room, you would likely need a 13-13.5 KW heater for the same size outdoor uninsulated sauna room.
Below is a table that shows the recommended sauna heater size in relation to the size of the sauna room, with 25% increase in KW for an uninsulated outdoor sauna room:
| Sauna Room Size (Cubic Feet) | Recommended Heater Size (KW) |
|---|---|
| 50-250 | 2.5-6.25 |
| 251-500 | 7.5-12.5 |
| 501-750 | 13.75-18.75 |
| 751-1000 | 20-25 |
| 1001-1250 | 26.25-31.25 |
| 1251-1500 | 32.5-37.5 |
| 1501-2000 | 38.75-50 |
| 2001+ | 51.25+ |
Please note that these numbers are based on the general rule of thumb that 1 KW of power is needed for every 50 cubic feet of space and an additional 25% increase to compensate for the lack of insulation of the sauna room. The desired temperature and type of sauna should also be considered when selecting a heater. It is always recommended to consult with a professional before making a final decision.
When choosing the right size sauna heater for an outdoor uninsulated sauna, it's important to also consider the amount of glass in the sauna. Glass can have a significant impact on the heating requirements of the sauna.
Saunas With Lots Of Glass
In summary, when choosing the right size sauna heater for an outdoor uninsulated sauna with a lot of glass, it's important to consider the added heat loss through the glass and to compensate for it by using a more powerful heater, adding insulation or using a sauna controller. Consult with a professional to determine the specific requirements for your sauna and to ensure that the heater you choose is appropriate for your sauna and your needs.
Take advantage of the efficiency of a barrel sauna!
Barrel saunas are known for their unique design, which typically involves a cylindrical shape made of wood. The efficiency of a barrel sauna in terms of heat-up time is significant when comparing to traditional "cabin" style saunas. If you're new to the world of outdoor saunas, check out our guide on Barrel Sauna Basics to get started, or explore 10 Things You May Not Know About Barrel Saunas for a deeper look at what makes them special.
Overall, the heat-up time of a barrel sauna can vary greatly depending on these and other factors. It is important to consult with a professional or check with the manufacturer's recommendations to get an estimate of the heat-up time for a specific barrel sauna model. You can also learn more about the benefits of owning one in our post on 5 Reasons You Should Consider a Outdoor Barrel Sauna.
To speak with one of our sauna experts you can email us at info@backcountryrecreation.com or give us a call at 877-446-3565 and speak to a sauna expert about your specific needs and get a solid recommendation on the correct sauna heater for your needs.