How to Choose the Best Sauna Heater: A Complete Buyer’s Guide

Selecting the right sauna heater is essential for creating an authentic, enjoyable, safe and efficient sauna experience. Whether you’re seeking the rustic charm of a wood-burning heater or the convenience of a modern electric model with smart control options, this guide will help you navigate the key considerations, ensuring you choose a heater that aligns with your sauna’s specifications and your personal preferences.

Choosing the right sauna heater depends on the size of your sauna, the sauna's specifications, location and your personal preferences. Image provided by HUUM. 

Determining the Appropriate Heater Size

Calculate Your Sauna’s Volume 

Begin by calculating the volume of the sauna to determine the necessary output of your heater. Often, a rough guideline is that 1 kW of heater power is required for every 1 m³ of sauna volume. However, the power of your sauna heater must be matched to the internal computational volume of your sauna. This volume is not just the physical dimensions (length x width x height) - it also accounts for materials and design features that influence heat loss. This includes uninsulated surfaces, such as windows and glass doors. 

Volume Adjustments for: 

• Glass Surfaces: Add 1m³ for every 1m² of single glazed glass.

• Uninsulated Walls: Add 1.5m³ for each square metre of other uninsulated surfaces. 

These adjustments account for heat loss through materials that are less efficient at retaining heat.

A slightly oversized heater is preferable to one that is underpowered, as you can moderate the output of a larger unit, but an underpowered unit will struggle to heat the space effectively. Selecting a heater that is too small for your space can lead to a range of issues that impact both performance and long-term costs. An underpowered heater will struggle to reach and maintain the desired temperature, resulting in extended heat-up times and a less enjoyable sauna experience overall. 

When a heater is consistently pushed to its limits, the heating elements will struggle to operate at their capacity for prolonged periods. This continual strain can lead to premature wear and tear on critical components, particularly the heating elements, increasing the likelihood of breakdowns and costly repairs. 

Additionally, an underpowered heater may fail to properly heat the sauna. This not only affects the ambient warmth but also compromises the quality of "löyly" (the burst of steam generated when water is poured onto the stones), which is central to an authentic sauna experience. 

Choosing the correct heater capacity for your sauna is therefore critical - not only for optimal performance and energy efficiency but also to avoid unnecessary maintenance costs in the future. 

Wood-burning sauna heaters create a traditional experience accompanied with the relaxing crackling of firewood. IKI Original Wood-Burning sauna heater. Image by IKI.

Sauna Heater Installation Considerations

Safety Distances

Adhering to manufacturer-specified safety distances between the heater and combustible materials is vital to prevent fire hazards. These distances vary by model and installation type (wall-mounted vs. floor-standing). In most cases, wood-burning models require larger safety distances and additional heat shielding if installed in a smaller sauna. 

Heater Placement

Strategic placement of the heater ensures even heat distribution: 

• Wall-Mounted Heaters: Ideal for smaller saunas to save space.

• Floor-Standing Heaters: Suitable for larger saunas, offering higher outputs and options for mounting into the sauna benching. 

Note: Always follow the manufacturer’s guidelines for installation and positioning. 

Design

There’s a rich variety of design options when it comes to both electric and wood burning sauna heaters. 

Electric sauna heaters range from wall-mounted to floor standing, from pillar shapes to rounded structures, and from fully encased surfaces to visible stones covered in a stainless-steel mesh. Some heaters can be easily mounted into the sauna benching, allowing for more space for the bathers. 

When it comes to choosing the design of the sauna heater, it’s worthwhile to have a think about the overall sauna area. Where will the heater be placed, the location of the door and the layout of the benches. Some sauna users prefer the stones to be only visible at the top of the heater and others would rather choose a heater body made of a stainless-steel mesh, so you can throw water to the sides of the heater as well. This is completely up to your personal preference and the type of a sauna aesthetic you’re after. 

Additional Features to Consider

• Design Aesthetics: Choose a heater that complements your sauna’s interior, whether you prefer a traditional or contemporary style. 

• Stone Capacity & Quality: A higher stone capacity can provide a more consistent and gentle heat, enhancing the sauna experience. Choose high-quality olivine diabase or vulcanite sauna stones designed for sauna heaters. Pouring water over the stones is key to creating the iconic “löyly.” Both wood-burning and electric sauna heaters are designed to handle ladles of water throughout the sauna session.

• Heat Shielding: You may want to consider heat shielding particularly for wood-burning sauna heaters to meet minimum safety distances to combustible materials.

• Energy Efficiency: Opt for models designed to minimise energy consumption without compromising performance. 

• Warranty and Support: Consider the manufacturer’s warranty and the availability of customer support services. 

Prioritise quality and a choose a reputable brand that provides good customer support. Tulikivi XL electric sauna heater recognised for its soapstone cladding that retains heat and offers a unique design feature.

 

Finnmark’s Sauna Heater Range

We offer a carefully curated selection of premium sauna heaters - from elegant electric models to robust wood-burners - all backed with expert advice and UK-based customer service.

 

Helo: For Those Seeking Simplicity with Nordic Design

Founded over a 100 years ago, Helo is one of the first large heater manufacturers in the world. Helo factory is located in the Southern-Finnish port city of Hanko, where they produce a variety of reliable and cost-effective heaters for those who value simplicity in design. With a variety of models that have manual dials for controlling the heaters, Helo offers easy to work with options for all types of saunas. 

Helo Rocher electric sauna heater is stylish floor standing model. Image by Helo

 

Maximum recommended run times for electric Helo heaters:

Domestic electric Helo heaters designed for private use should not be on for more than 6 hours at a time. 

Commercial electric Helo heaters such as those in spas, swimming pools and gyms can be on around the clock as long as they are supervised. There should be at least one 6- hour period within 24 hours where the heater is switched off. This can be 6 hours straight or broken into 2-hour intervals. As an example: 3 x 2 hour off times within 24 hours.

HUUM: Where Style and Technology Meet

HUUM is a young Estonian sauna company, who have invested in a carefully designed selection of stylish and modern sauna heaters. The signature HUUM heaters feature a modern stainless-steel structure encasing a large amount of sauna stones. HUUM heaters have been recognised for their innovative designs and controlling options. Although the company does not have the same long-standing establishment in the sauna heater market as the majority of other heater suppliers, they are the “go-to" choice for the modern-day sauna user. The HUUM heaters will stand as a noticeable design feature in both commercial and home saunas.

HUUM Steel electric sauna heater is the perfect choice for a modern sauna. Image by HUUM

 

Narvi: An Excellent All-Rounder 

Narvi is a Finnish sauna heater manufacturer, founded in 1937. All Narvi heaters bear the Finnish Key Flag Symbol indicating that they are designed and made in Finland, with 95% or more of the production within the country. Narvi heaters are an authentic, safe and quality product with a wide range of electric and wood burning heater options. 

Narvi has a large variety of heater models to suit all budgets, functionality needs and design tastes. 

Narvi Smooth electric sauna heater can be also integrated into the benching. Image by Narvi

 

IKI: Where Durability is Paramount

IKI-Kiuas has been providing Finnish craftsmanship for sauna enthusiasts since the mid-nineties. The signature IKI heaters have a stainless-steel mesh frame alongside a substantial stone capacity, providing a uniquely effective, oxygen rich and soft steam experience. IKI has over 40 years’ experience in welding black iron and stainless- steel, and their heaters are one of the most durable in the market. 

Although there isn’t a large variety of designs to choose from, the high-quality IKI heaters will last for years on years through heavy sauna use. An IKI heater is ideal for the hard-core “löyly” lovers. 

Commercial or Domestic IKI Heater?

Any heaters from 12kW upwards do not have specific limitations when it comes to maximum run times. As such, even 12kW-15kW electric sauna heaters by IKI can be chosen for a commercial sauna. This is as long as the size of the sauna falls within the recommended capacities outlined by the supplier. 

The IKI Pro heaters are specifically designed for large, commercial saunas. 

IKI Original wood burning sauna stove is a classic choice. Image by IKI Kiuas

 

Tulikivi: Leader in Quality and Experience

Tulikivi is known for high-quality, soapstone cladded sauna heaters and fireplaces. The exclusive soapstone is over 2 billion years old and carries heat storing capacities, wrapped in a beautiful look and feel. 

Because of the natural qualities of soapstone, each Tulikivi product is unique with no heater looking exactly like the other. The heaters have minimal safety distances due to the soapstone cladding that will get hot but won’t burn you if you accidentally brush your skin on it. Tulikivi is a great heater choice in commercial saunas where safety is a concern, as well as in family saunas used by young children. 

Tulikivi Naava electric sauna heater. Image by Tulikivi

 

Additional Resources

Learn about Sauna Heater Running Costs

Check How To Select, Inspect & Change Your Sauna Stones

Explore our full range of Electric Sauna Heaters

View our Wood- Burning Sauna Heaters

Get in touch with our sauna design consultants for additional advice on choosing the perfect sauna heater for your home or business.

 Need help building your sauna? Check our step-by-step guide.