Saunum heaters solve one specific problem: the large temperature difference between your feet and your head in a conventional sauna. The Estonian manufacturer builds an air-circulation system into its heaters that draws cooler air from floor level, mixes it with hot air from above the stones, and redistributes it — deliberately flattening a gradient that in a normal sauna can be 30–40°F across three feet of vertical space.
That is a real problem and Saunum addresses it directly, which neither Harvia nor HUUM attempts. Whether it is your problem is the whole buying decision, and this guide is built around answering that.
The problem Saunum is solving
In any conventional sauna, heat stratifies. Hot air rises; cooler air sits at floor level. The result, in a room reading 190°F at the ceiling sensor:
| Position | Typical temperature |
|---|---|
| Ceiling / sensor | 185–195°F |
| Upper bench, head height | 180–190°F |
| Upper bench, foot level | 160–175°F |
| Lower bench | 145–165°F |
| Floor | 100–120°F |
What that feels like in practice: your ears and scalp are uncomfortably hot while your feet are merely warm. Experienced bathers manage it by putting their feet up on the bench — which works, and is why every Finnish sauna guide tells you to do it — but it does not eliminate the gradient, it just moves you into a narrower band of it.
Who this affects most:
- Anyone using the lower bench — children, older family members, anyone with lower heat tolerance
- Rooms where the bench height cannot be optimal because of ceiling constraints
- Households where one person wants 190°F and another finds it unbearable
- Anyone who finds the heat "harsh on the head" rather than enveloping
Who it barely affects: a single experienced bather on the upper bench with their feet up, in a well-ventilated room with a properly positioned heater. If that is you, the gradient is not costing you much and Saunum's advantage is smaller.
How the technology works
Saunum's heaters incorporate an air-mixing system — the specifics vary by model family — that takes cool air from the lower part of the room, combines it with heated air from the stone zone, and distributes the mixed air back into the room.
The intended result:
- A much smaller difference between floor and ceiling temperature
- Heat that feels more evenly enveloping rather than concentrated overhead
- The lower bench becoming genuinely usable rather than a consolation seat
- Steam distributed through the room after a water throw rather than pooling at the ceiling
- A room that can be run at a slightly lower thermostat setting while feeling equivalent, because more of the room is actually at the useful temperature
What it does not change: it is still a traditional stone-topped sauna heater. You still pour water on stones, you still get löyly, you still need the same electrical circuit, ventilation and room construction. The circulation is an addition to a conventional heater, not a replacement for one.
Circulation reduces the gradient; it does not abolish physics. Hot air still rises. What changes is the magnitude — a room that had a 40°F spread might have a 15–20°F one. That is a meaningful difference in how the room feels, particularly on the lower bench, rather than a transformation into a uniformly heated box.
The model families
Air-circulation electric heaters. The core range, in wall-mounted and floor-standing formats, at residential outputs. This is what Saunum is known for.
Components and accessories. Sensors, control units, guards, stones and replacement parts specific to the range.
Controls. App and panel control is available across the range; confirm which control unit a given model requires and whether it is included.
Range breadth. Narrower than Harvia's by a long way, and focused on conventional residential room sizes. If your room needs an unusual mounting or an unusual output, check availability early.
Sizing a Saunum heater
The base method is the same as for any stone heater.
Volume (ft³) ÷ 45–50 = baseline kW
Then add:
| Feature | Add |
|---|---|
| Glass door | +0.5 kW |
| Glass panel or wall | +1.5–2 kW per m² |
| Tile, stone or concrete surface | +1.5 kW per m² |
| Uninsulated log wall | +1.5 kW per m² |
| Uninsulated exterior wall | +0.5–1 kW |
| Outdoor, cold climate | +1–2 kW |
Round up, and confirm the result sits inside the model's published minimum and maximum room volume.
A Saunum-specific consideration. Because the circulation system distributes heat more evenly, more of the room's volume is actually at working temperature — which means the heater is doing genuine work on the whole space rather than concentrating it near the ceiling. Follow the manufacturer's published room volume range rather than trying to adjust the standard formula yourself; the published figures already account for how the system behaves.
Do not undersize on the assumption that even heat means you can run cooler. The room still has to reach and hold temperature against the same losses.
Full method in what size sauna heater you need.
Installation considerations
Ventilation still matters. A common misunderstanding is that a circulating heater replaces the need for proper sauna ventilation. It does not. Ventilation supplies fresh air and removes stale air; circulation moves the air that is already in the room. You still need an inlet low near the heater and an adjustable outlet on the opposite wall. See sauna ventilation.
Sensor position is specified by the manual and matters as much as on any heater — out of the ventilation path, at the stated distance below the ceiling. A circulating room has different airflow patterns than a conventional one, so following the manufacturer's position rather than general advice is particularly important here.
Clearances as published for the model, checked against the bench plan before benches are built.
Electrical is the same as any heater at that output — a dedicated 240V circuit, roughly 30–40A for 6 kW and 40–50A for 8 kW. See sauna electrical requirements.
Guard rail as required by the listing, often sold separately.
In a conventional sauna you design benches around the gradient — upper bench high, close to the heater's stone level. With circulation, the lower bench is genuinely usable, which means a two-tier layout serves a wider range of people and a three-tier arrangement may be unnecessary. See how to design a custom sauna.
Saunum against the alternatives
| Saunum | Harvia | HUUM | |
|---|---|---|---|
| Distinguishing feature | Air circulation, even heat | Range breadth and support | Design and stone capacity |
| Range size | Focused | Very wide | Focused |
| Commercial options | Limited | Extensive | Limited |
| Löyly intensity | Good | Varies by model | Excellent |
| Heat evenness | Best in class | Conventional | Conventional |
| Design presence | Contemporary, restrained | Varies | Sculptural |
| Best for | Mixed-tolerance households, lower-bench users | Any build, unusual requirements | Design-led rooms, löyly enthusiasts |
The honest framing: Saunum is not competing on the same axis as the other two. If the thing that bothers you about saunas is that your head roasts while your feet stay cool, Saunum is the brand that took that problem seriously.
If you want maximum löyly, compare HUUM. If you want the widest choice and the deepest support network, compare Harvia. See also Harvia vs HUUM.
Other ways to reduce the gradient
Worth knowing, because some of them are free and you may not need a specialised heater at all.
Put your feet up on the bench. The single most effective free intervention. Your feet are otherwise sitting in the coolest air in the room, 20–40°F below your head. Every Finnish sauna guide says this and most people ignore it.
Get the ventilation right. An inlet low near or under the heater and an adjustable outlet on the opposite wall sets up a convection loop that moves heat around the room rather than letting it stack at the ceiling. A sauna with no working ventilation has a much worse gradient than one with it, and fixing this costs almost nothing during a build. See sauna ventilation.
Raise the benches. Your head on the upper bench should be at or below the top of the stone basket. Benches too low relative to the heater put you in the cool half of the room. This is a design decision made once.
Use a heater with stones exposed on multiple sides. Open-cage and tower formats radiate in all directions rather than forward only, which distributes heat more evenly than a recessed basket.
Throw water. Löyly briefly mixes the air and carries heat downward. It does not permanently flatten the gradient, but it evens things out during a round.
Lower the thermostat and sit higher. A room at 175°F with your head near the ceiling can feel more comfortable than one at 195°F where you are trying to sit low to escape the heat.
When none of that is enough: if you have done all of the above and the lower bench is still unusable — which is common in rooms with ceiling constraints, or in households where one person simply cannot tolerate the upper bench — that is precisely the case Saunum exists for.
Who should buy a Saunum
Strong fit
- Your household has genuinely mixed heat tolerance and you are tired of compromising on a thermostat setting
- Children or older family members will use the sauna and will sit on the lower bench
- Ceiling height constraints mean the benches cannot be at the ideal level
- You find conventional saunas harsh on the head
- You want a room where everyone is comfortable at one setting rather than negotiating bench height
- The sauna is a family room rather than an enthusiast's solo space
Probably not the priority
- You bathe alone on the upper bench with your feet up and the gradient has never bothered you
- Maximum löyly intensity is the goal — high stone mass is a more direct route
- The room is very small, where the vertical gradient is compressed anyway
- You need an unusual mounting or output, or a commercial-duty heater
- Long-term parts availability across fifteen years is your primary concern
Sit on the lower bench of a conventional sauna for a full round. If it felt mild and you spent the whole time wishing you could move up, Saunum is addressing your problem. If you were perfectly comfortable, it is solving something you do not have.
What to check before ordering a Saunum
- Calculated kW with adders, inside the model's published room volume range
- Clearances against your bench plan, before the benches are built
- Which control unit the model requires, and whether it is included
- Whether the app module is separate
- Guard rail included or extra
- Stone capacity and specified stone type — see sauna stones
- North American listing for your market
- Breaker and conductor size against panel capacity
- Sensor position per the manual, given the room's circulation pattern
- Parts availability and warranty terms in your market
- Whether your planned ventilation scheme is compatible with the manufacturer's guidance
Running cost and long-term ownership
Energy use. A circulating heater draws the same power as a conventional one at the same kW rating, plus a small amount for the circulation fan — a negligible addition next to a 6–9 kW element load. At temperature, both draw only what the room loses.
One possible saving. Because more of the room's volume is at a usable temperature, some owners find they can run a lower thermostat setting for an equivalent experience. A room held at 175°F instead of 190°F loses less heat and therefore costs less. Whether this materialises for you depends on how you bathe, but it is a plausible offsetting effect rather than a marketing claim. See how much it costs to run a sauna.
The extra component. The circulation system is a moving part that a conventional heater does not have. That is worth knowing rather than worrying about — but it is one more thing that can eventually need service, and it makes parts availability and warranty terms a slightly more important question here than on a purely resistive heater. Ask about both before ordering.
Stones and elements behave as they do on any heater: stones replaced every one to three years, elements likely once over a fifteen-year life, and both prolonged by loose stone stacking and by drying the room out after each session.
Documentation to keep: the model and serial number, the installation manual, the electrician's invoice and the warranty terms. On a heater with a distinctive system, having the manual to hand matters more than usual if anything ever needs diagnosing.
Frequently Asked Questions
What makes Saunum sauna heaters different?
Saunum builds an air-circulation system into its heaters that draws cooler air from floor level, mixes it with hot air from above the stones and redistributes it, substantially reducing the temperature difference between floor and ceiling. In a conventional sauna that gradient can be 30–40°F across three feet; Saunum's aim is to compress it so the whole room, including the lower bench, is at a usable temperature.
Is a Saunum heater worth it?
If your household has mixed heat tolerance, if children or older family members will use the lower bench, or if you find conventional saunas harsh on the head while your feet stay cool, yes — it addresses that problem directly and no other mainstream brand does. If you bathe alone on the upper bench and the gradient has never bothered you, a conventional heater with high stone mass is a better use of the money.
Does a Saunum heater still produce löyly?
Yes. It is a conventional stone-topped sauna heater with a circulation system added, so you pour water on hot stones exactly as you would on any other heater. The circulation additionally distributes the steam through the room rather than letting it pool at the ceiling. For maximum steam intensity, heaters built specifically around very high stone mass have the edge.
Do you still need ventilation with a Saunum heater?
Yes. Circulation moves the air already in the room; ventilation supplies fresh air and removes stale air. You still need an inlet low near the heater and an adjustable outlet on the opposite wall. Because the airflow pattern in a circulating room differs from a conventional one, follow the manufacturer's ventilation and sensor-position guidance specifically.
Saunum vs Harvia — which should I choose?
They compete on different axes. Harvia offers by far the widest range, unusual mountings, commercial-duty models and the deepest parts network, which makes it the safe default for almost any build. Saunum offers even floor-to-ceiling heat, which is a specific advantage for households with mixed heat tolerance or lower-bench users. Choose Saunum if the gradient is your complaint; choose Harvia if range or support is.
Even heat, top to bottom
Saunum air-circulation heaters in wall-mounted and floor-standing formats, with the controls and components to match.
Shop Saunum Heaters All Sauna HeatersRelated guides
- Harvia vs HUUM
- Harvia Sauna Heater Buying Guide
- HUUM Sauna Heater Buying Guide
- How Hot Should a Sauna Be?
- Sauna Ventilation: Complete Guide
Published by Finest Saunas