Sauna Heaters

Electric vs. Wood-Burning: Which Should You Buy?

This is the first real decision in any sauna build, and it's mostly a lifestyle question — not a performance one. Both types get a sauna to 180°F. Both let you throw water on stones for steam. What differs is the experience around the heat.

Electric heaters plug into a dedicated circuit, heat to temperature in 30–45 minutes, and turn off with a button press. You set a temperature, it holds that temperature, and you walk back to your house. The vast majority of our customers choose electric because it fits modern routines — short sessions, no fuel to store, no ash to clean.

Wood-burning stoves deliver a different experience: a softer, more radiant heat, the crackle of a fire, the smell of burning wood. You can't hit a button and walk away. You have to split wood, load the firebox, and tend the fire for about 15–20 minutes before you climb in. For off-grid cabins, rural properties, or owners who see the fire itself as part of the ritual, it's the right choice. For everyone else, the answer is almost always electric.

How to Size a Sauna Heater

The rule that holds across every brand and model: roughly 1kW of heater power per 50 cubic feet of sauna interior. Multiply your sauna's interior length × width × height to get cubic feet, then divide by 50. Add 10–15% if you have uninsulated glass walls, an exterior door, or are in a cold climate.

To translate that into real examples from this collection:

• 4.5kW: Covers 100–247 cu ft — a 1-person indoor sauna or compact cube.
• 6kW: Covers 170–353 cu ft — the most common size for 2–3 person indoor saunas.
• 8kW: Covers 250–425 cu ft — mid-size saunas, most 4-person outdoor cabins.
• 9kW: Covers 282–530 cu ft — the workhorse size for outdoor saunas in the 5–6 person range. See every option on our 9kW heater page.
• 10.5kW: Covers 330–635 cu ft — the largest single-phase residential heater before you need commercial three-phase wiring. Compare 10.5kW models here.
• 12kW and above: Commercial spaces, large barrel saunas, or rooms with significant glass exposure.

Undersizing is the more common mistake. A 6kW in a 400 cu ft room will technically get hot, but it'll take an hour and struggle to recover after you throw water on the stones. When in doubt, go one size up.

Brands We Carry

HUUM is the Estonian brand that redefined what a sauna heater could look like. Their DROP and CLIFF series wrap the heating elements in clean steel shells with massive stone baskets — the HUUM Drop holds 121 lbs of stones, the HUUM CLIFF holds 200+ lbs, and the flagship HIVE takes up to 595 lbs. More stones = more thermal mass = softer, steamier heat. HUUM also makes the UKU controller system, which pairs over WiFi to any HUUM heater. See the full HUUM lineup for every model and stone capacity.

Harvia is the Finnish reliability workhorse. Founded in 1950, still the most widely installed heater brand in home saunas worldwide. The KIP, Cilindro, Virta, and Spirit series cover every size from 4.5kW to 15kW. Controllers range from a simple built-in dial (KIP-B) to the full Xenio WiFi system. If you want proven performance without worrying about firmware updates, Harvia is the default answer. Their bundled heater packages come with stones, controller, and all the parts you actually need.

Saunum is the newer entrant that solved a problem most Finnish brands ignored: uneven heat. Traditional heaters stack all the hot air at the ceiling, leaving your feet cold on the lower bench. The Saunum Air series uses a patented climate equalizer to circulate air so the temperature between your head and feet differs by a few degrees instead of 40°F. Worth considering if you've ever sat in a sauna and thought "why are my legs freezing."

Amerec is a US-built brand making some of the smallest electric heaters on the market — the Amerec Junior 2.2kW and 3kW units fit one-person closet-sized saunas most other brands won't even sell for.

Stones, Controllers, and What You Actually Need

A sauna heater is rarely a single-box purchase. Most setups need four things: the heater itself, stones, a controller, and proper wiring. Here's what's usually included versus what you have to buy separately.

Stones are always sold separately unless you're buying a bundled package. Budget 50–100 lbs for a mid-size heater, up to 200+ lbs for a HUUM HIVE. Stones are not interchangeable — use olivine diabase sauna rocks from HUUM or Harvia, not decorative rocks from a landscaping store. The wrong stone cracks, crumbles, or pops under thermal stress.

Controllers come in three flavors: built-in (basic dial, on the heater itself — simplest), external wall-mounted (digital display with timer), and WiFi-enabled (phone app control, remote start). HUUM heaters require a separate UKU controller. Most Harvia heaters have a built-in option (KIP-B, Cilindro-HB) or external (Xenio series). If remote start from your phone is the priority, skip straight to our WiFi-controlled heaters.

Accessories like safety rails, embedding flanges (for bench-embedded install), and water buckets don't ship with most heaters. Check the accessories page once you've picked your heater.

Electrical Requirements (Read This Before You Buy)

This is where most first-time buyers run into trouble. Home saunas do not plug into standard outlets. A 6kW heater on 240V single-phase pulls roughly 25 amps — meaning a dedicated 30A circuit. A 9kW heater pulls ~38 amps on a 40A circuit. 10.5kW heaters sit right at the edge of single-phase residential (50A circuit on 240V) and often require a sub-panel upgrade for older homes.

Before you click "buy" on any heater above 6kW, run the math on your panel's free capacity, the distance from your panel to the sauna, and the wire gauge required. Our full electrical requirements walkthrough breaks this down with amperage tables and wire sizing — read it before an electrician quote, not after.

Every heater we sell must be installed by a licensed electrician. If a retailer tells you "you can DIY this" for anything above a 2.2kW plug-in unit, they're wrong.