HUUM HIVE Flow Mini LS 8.5kW Wood-Burning Sauna Heater Package
HUUM HIVE Flow Mini LS 8.5 kW wood-burning stove, 231 lb of stones, LS Protective Bedding S and a HUUM chimney kit in one package, for 212–494 cu ft sauna rooms
In stock
Estimated delivery
7–12 days after you order
In stock
Estimated delivery
7–12 days after you order
In stock
Estimated delivery
7–12 days after you order
In stock
Estimated delivery
7–12 days after you order
- HUUM: 75% of the firewood's heat goes into the sauna, not up the chimney
- Firebox passes through the wall, so the fire is lit from the next room
- 231 lb of HUUM stones included
- Description
- What's Included
- Specifications
- Installation
- Documents
- Warranty
What is the HUUM HIVE Flow Mini LS 8.5 kW wood-burning package?
The HUUM HIVE Flow Mini LS 8.5 kW package combines four parts: the HUUM HIVE Flow Mini LS wood-burning sauna stove, 7 boxes (231 lb) of HUUM Stones 24, the HUUM LS Protective Bedding S that goes under the stove, and one HUUM chimney kit, chosen by option. It is sized for sauna rooms of 212–494 cu ft, burns firewood only and needs no electricity. The package price is the sum of the four parts; ordering them together means the stones, bedding and chimney kit are already matched to the stove.
The HUUM HIVE Flow Mini LS stove stands on the floor, holds 231 lb of 2–4" stones (7 boxes of 33 lb) in a metal grate around the stove body, and connects to the chimney at the top or the back. The LS version has a firebox 4.7" (120 mm) longer than the HIVE Flow Mini's, built to pass through a non-combustible wall, so the fire is lit and fed from the adjacent room while the stove body and its stones stay in the sauna.
HUUM says 75% of the heat from the firewood goes directly into the sauna rather than escaping up the chimney, and that the large stone mass keeps giving steam for more than 30 minutes after the fire is out. In the Engineering Test Institute's emissions report, the HIVE Flow Mini and HIVE Flow Mini LS reached 75.1% gross efficiency, with particulate emissions of 14 mg/m³. HUUM says its design reduces fire risk, allowing a snug installation. A large glass door shows the fire, and the furnace design is patent pending.
Which chimney kit should I choose?
Choose the kit by where the chimney leaves the sauna. HUUM lists all four for the HIVE Flow; only the backside kit uses the stove's rear connection.
| Connects at | Route out of the sauna | |
|---|---|---|
| Thru-Wall | Top | Rises from the top of the stove, turns 90° through the wall and runs up the outside of the building |
| Thru-Flat or Curved Ceiling | Top | Goes straight up through a flat or curved (barrel) ceiling and roof |
| Thru-Angled Ceiling | Top | Goes up through the ceiling and out through a roof pitched 0–20° |
| Thru-Wall Backside Connection | Back | Leaves the back of the stove straight through the wall, then runs up the outside of the building |
What's included in the HUUM HIVE Flow Mini LS 8.5 kW package?
HUUM HIVE Flow Mini LS stove
- The sauna stove
- Metal stone grate
- Ash grate
- Ash drawer
- Cleaning hatches (2)
- Metal fixing plates (2), used for a back chimney connection
- Splints
- Heat-resistant glove
- Installation and operation manual
HUUM Stones 24
- 7 boxes × 33 lb = 231 lb of rounded 2–4" (5–10 cm) HUUM Stones 24
HUUM LS Protective Bedding S
- HUUM LS Protective Bedding S, made for the HIVE Flow Mini LS
- 19.7" × 24.8" (500 × 630 mm) overall, including an 11.4" × 6" (290 × 150 mm) tongue under the extended firebox
- Height adjustable 2.2–3" (56–75 mm) on six feet
- Carries up to 661 lb (300 kg)
- Also sold on its own: LS Protective Bedding S
HUUM chimney kit
- One kit, by the option you choose: HUUM Thru-Wall Chimney Kit, HUUM Thru-Flat or Curved Ceiling Chimney Kit, HUUM Thru-Angled Ceiling Chimney Kit, HUUM Thru-Wall Backside Connection Chimney Kit
- Each kit's parts list is on the kit's own product page
What you still need
- A certified installation expert to connect the stove to the chimney
- On a combustible floor, a sheet-metal plate in front of the stove door: at least 4" past each side of the door opening and 15 3/4" forward (HUUM's manual)
- A non-combustible wall for the firebox; the Mounting Collar S frames the opening and is offered with this package
- Optional: the HUUM stone cage (Cage HSTV), offered with this package
HUUM HIVE Flow Mini LS stove specifications
| HUUM model and part number | HIVE Flow Mini LS, H1018012 |
|---|---|
| Heat output | 8.5 kW nominal |
| Sauna room volume | 212–494 cu ft (6–14 m³); add 3.3 cu ft per sq ft of uninsulated brick, tile or glass wall |
| Dimensions | 34.8" H × 17.7" W × 24.1" D (884 × 450 × 613 mm); the door handle adds 1.7" (44 mm) to the depth |
| Weight | 130 lb (59 kg) without stones |
| Stones | Included: 7 boxes × 33 lb = 231 lb (105 kg) of 2–4" HUUM Stones 24 |
| Floor protection under the stove | Included: the HUUM LS Protective Bedding S; HUUM requires a non-combustible base on a wood or other combustible floor |
| Floor plate in front of the door | Required on a combustible floor, at least 4" past each side of the door opening and 15 3/4" forward; not included |
| Chimney | Included: one HUUM chimney kit, by the option you choose; a certified installer connects it |
| Chimney connection on the stove | Top or back; 4.5" (114 mm) chimney leg; the chimney must be temperature class T450 with at least 16 sq in (10,400 mm²) cross-section |
| Through-wall installation | Applies to this model: the firebox, 4.7" (120 mm) longer than the HIVE Flow Mini's, passes through a non-combustible wall up to 4" thick, or 6" with a mounting collar |
| Mounting collar | Optional, not included; needed only in a wall 4–6" thick. The HUUM Mounting Collar S is offered as an add-on with this package |
| Stone cage | Optional, not included; the HUUM Cage HSTV is offered as an add-on with this package |
| Electrical connection | None needed; wood-fired, no controller |
| Fuel | Firewood only, hardwood or softwood, 10–15% moisture |
| Firewood length | 12" (recommended and maximum) |
| Flue gas temperature | 606°F average and 650°F maximum at nominal output |
| Efficiency and emissions | 75.1% gross efficiency; CO 686 mg/m³ and particulates 14 mg/m³ at 13% O₂ (emissions report, Engineering Test Institute, Brno) |
| Emission standards | Certified to EN 15821 under the EU Construction Products Regulation (certificate CPR-B-00657-24); meets Germany's 1. BImSchV Stage 2, per the emissions report of the Engineering Test Institute, Brno |
| Sauna room height | 75" (1,900 mm) minimum; 79–91" recommended |
| Made in | Estonia; furnace design patent pending |
| Warranty | 3 years private use, 1 year commercial use (HUUM); the door glass, ash grate and stones are excluded |
All four HIVE Flow stoves, and a package for each, are in the HUUM HIVE Flow collection; HUUM's HIVE Wood stoves are with them in the HUUM wood-burning sauna stove collection.
How is the HUUM HIVE Flow Mini LS 8.5 kW package installed?
The HIVE Flow Mini LS stands on a non-combustible floor strong enough to carry it and its 231 lb of stones; HUUM names a concrete floor at least 2" (50 mm) thick as suitable. On wood or another combustible floor, HUUM's manual makes a non-combustible base mandatory, such as the HUUM LS Protective Bedding S included in the package, with a ventilation gap of at least 1 3/16" (30 mm) under it, and it is also recommended over underfloor heating pipes. A sheet-metal plate must cover the combustible floor in front of the stove, reaching at least 4" (100 mm) past each side of the door opening and 15 3/4" (400 mm) forward, with the edge nearest the stove bent up so coals cannot slide under it.
Installing the HIVE Flow Mini LS through a wall
The HIVE Flow Mini LS's firebox passes through a non-combustible wall (stone or concrete, for example), so the stove body and its stones sit in the sauna while the fire door opens into the adjacent room. HUUM's manual allows a wall up to 4" (100 mm) thick, or up to 6" (150 mm) with the Mounting Collar S, keeps at least 2" (50 mm) between the stove and the wall, and requires that no combustible wall material protrudes into the opening.
| Non-combustible wall, at least (W × H) | Wall opening, at least (W × H) | |
|---|---|---|
| Stove on the floor, no collar | 26 × 41 in (650 × 1,050 mm) | 11 × 19 in (270 × 470 mm) |
| Stove on the floor, with the HUUM mounting collar | 26 × 41 in (650 × 1,050 mm) | 17 × 22 in (435 × 560 mm) |
| Stove on HUUM protective bedding, with the collar | 26 × 43 in (650 × 1,100 mm) | 17 × 24 in (435 × 615 mm) |
HUUM HIVE Flow Mini LS safety distances
Keep at least these distances from the HIVE Flow Mini LS to walls, benches and anything that can burn. The letters match HUUM's drawing.
| A: sides and back | 6" (150 mm) |
|---|---|
| B: in front of the door | 20" (500 mm) |
| C: total side-to-side span (A + stove + A) | 30" (750 mm) |
| Above the stove | 40" (1,000 mm) |
| To a non-combustible wall | 2" (50 mm) |
A non-combustible protective screen cuts the side distances by 50% (single screen) or up to 75% (double screen), and the distance to the ceiling by 25% (single screen only); the distance is still measured to the combustible surface. HUUM asks you to check local safety rules before reducing any distance. The sauna room must be at least 75" tall; HUUM recommends 79–91", with 44–51" from the top bench to the ceiling.
Connecting the HIVE Flow Mini LS to a chimney
Only a certified installation expert may connect the HIVE Flow Mini LS to the chimney. HUUM's manual calls for a chimney of temperature class T450 with a cross-section of at least 16 sq in (10,400 mm²), joined to the stove's 4.5" (114 mm) chimney leg at the top or the back. For a back connection the bolted chimney leg and its cover plate swap places, and two ribs of the stone grate are cut and fixed with the two metal fixing plates in the box. Seal the joints with heat-resistant rope or stone wool. Because the flue gas stays below 752°F (400°C), HUUM allows the stove to share an existing flue that already serves a fireplace, if your local authority and fire department agree.
| Connects at | Route out of the sauna | |
|---|---|---|
| Thru-Wall | Top | Rises from the top of the stove, turns 90° through the wall and runs up the outside of the building |
| Thru-Flat or Curved Ceiling | Top | Goes straight up through a flat or curved (barrel) ceiling and roof |
| Thru-Angled Ceiling | Top | Goes up through the ceiling and out through a roof pitched 0–20° |
| Thru-Wall Backside Connection | Back | Leaves the back of the stove straight through the wall, then runs up the outside of the building |
HUUM's manual asks for fresh supply air directed as close to the HIVE Flow Mini LS as possible, and warns that forced (mechanical) ventilation can starve the fire of combustion air, so check the ventilation design before the first sauna. It also advises checking local fire safety rules before installing a wood-burning stove.
Before the first fire: HUUM's outdoor burn-in
HUUM's manual requires the HIVE Flow Mini LS to be fired outdoors at least once before it is installed, because the protective paint on the stove body gives off unpleasant fumes while it cures. Remove the stone grate, lay no stones, fit the ash grate, ash drawer and cleaning hatches, and burn one or two loads of firewood in a sheltered, well-ventilated spot with the door slightly open, never closed, until no smoke or steam comes off the surface. Do not throw water on the stove. A length of flue pipe on the chimney leg improves the draft.
Lighting the HIVE Flow Mini LS and adding wood
Burn firewood only, hardwood or softwood at 10–15% moisture, in logs no longer than 12" (30 cm), weighing 0.8–1.5 lb each. Lay thin wood at the bottom, the thickest in the middle and kindling on top, then light it from the top. Keep the ash drawer open (its limiter allows 1/8") for no more than 15 minutes, then close it for the rest of the heating. Add wood only once the previous load has burned down to glowing coals, filling the firebox to no more than two thirds of its height. HUUM's maximum loads for the HIVE Flow Mini LS are 8 lb (3.8 kg) to start, then 4 lb (1.8 kg) and 3 lb (1.4 kg), and no more than 8 lb (3.5 kg) per hour. If the stove surface glows red it is overheating: close the air valve under the door at once.
Stones, steam and yearly care
Wash the 231 lb of stones, check that the cleaning hatches are in place, then lay the stones evenly, layer by layer, level with the top of the grate, without forcing any between the grate and the stove body. Make steam only once the stones are fully hot: about 1/3 cup (80 ml) of water at a time, never salt or chlorinated water. HUUM says the stones keep giving steam for more than 30 minutes after the fire is out. Have a chimney sweep clean the chimney, the flue connections and the stove's own flues at least once a year, check the stones yearly, and expect to renew them about every two years. Check the door seal each time you clean the glass, and never heat the stove with cracked glass.
HUUM warranty periods
HUUM's limited warranty (Limited Warranty Terms and Conditions, US, v2) covers new HUUM products bought from HUUM or its authorized dealers, such as Topture, against defects in materials and workmanship. The period starts on the date the end user buys the product.
| HUUM product | Private use | Commercial use |
|---|---|---|
| Electric sauna heaters | 3 years | 1 year |
| Wood-burning sauna stoves | 3 years | 1 year |
| Control units (UKU) | 3 years | 1 year |
| Spare parts | 1 year | 1 year |
HUUM counts as commercial use a business using the product commercially, a private owner using it commercially, or a private owner using it for more than 1,500 hours in 12 months.
What the warranty does not cover
- Heating elements of electric heaters
- HUUM accessories, such as rails, reflectors, flanges, protective bedding and chimney parts
- Door glass and ash grate of wood-burning stoves
- Sauna stones
- All controller sensors
- Damage from a heater that is the wrong size for the room, from unsuitable stones, or from installation, use or maintenance that does not follow HUUM's manuals
What keeps the warranty in effect
- Inspect the product when it arrives and report any visible damage within 7 days, with photos, before installing it.
- Install it following HUUM's manual and local building, electrical and fire codes. An electric product must be connected by a licensed electrician, with proof of the installation.
- Report a defect within 30 days of finding it. For products bought from Topture, report it to Topture, which passes the claim to HUUM and helps with troubleshooting.
