Carbon Smart™ Indoor Sauna Kit — 5’ × 8’ × 8’
This is a DIY indoor sauna room kit from Finnish Sauna Builders' Carbon Smart™ line. The kit arrives with all interior components precisely cut to your room dimensions — walls, ceiling, benches, door, flooring, vents, and accessories — ready for installation into your framed and wired space. Wood is Thermo Poplar throughout, a thermally modified wood processed without added chemicals. Choose your bench configuration, accessory package, and Harvia heater at checkout.
What’s Included
- Foil vapor barrier
- Ergonomic backrests (shipped flat; on-site spacers can be added for angled pitch)
- 1×4 tongue & groove boards — walls and ceiling, Thermo Poplar
- Clear 1×4 bench boards with supports — 20″ deep, Thermo Poplar, custom-built to your chosen configuration
- Corner moldings — walls, ceiling, and baseboards, Thermo Poplar
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All-glass sauna door with wood handles and trim
- Frame: 27.2″ × 78.7″ (690 × 2000 mm)
- Glass: 24.4″ × 77.3″ (620 × 1963 mm)
- Frame thickness: 1.65″ × 3.6″ (42 × 92 mm)
- Rough opening required: 28″ × 80″
- Duckboard flooring — walk area, Thermo Poplar
- Upper and lower vent grills
- Traditional sauna bucket with liner and ladle
- Sauna thermometer
- Headrest
- Marine-grade, wall-mount, vapor-proof sauna light
- Detailed installation instructions
Note: Shipment includes an all-glass door; some product photos may show a glass wall for reference. Backrests are shipped flat; if you’d like an angled backrest, additional spacers can be easily created on-site to achieve your desired pitch. Wall boards run horizontal by default unless room width exceeds 8’, in which case an interior seam is added where boards meet.
Wood — Thermo Poplar
All Carbon Smart™ interior components are Thermo Poplar — a sustainably sourced wood thermally modified at approximately 374°F using steam under atmospheric pressure, with no added chemicals. The process improves dimensional stability, reduces equilibrium moisture content, and enhances resistance to humidity and temperature fluctuations. Suitable for indoor sauna environments.
Customization Options
- Bench configuration — select from layouts shown in product images
- Accessory package — No Accessories, Bench Skirting, LED Under Bench Lighting, or Luxury Package (Skirting + LED Under Bench Lighting)
- Heater — No Heater, or choose from six Harvia 8kW models (see comparison chart below)
Installation Requirements
- Customer-supplied: framing, insulation, electrical wiring, and exterior wall covering
- Ceiling height: 8 feet recommended per manufacturer safety and clearance guidelines; contact support for custom ceiling heights
- Electrical: requirements depend on the Harvia heater selected; refer to each heater model’s individual specifications for voltage, wattage, and circuit requirements before installation
- Weight: 800 lbs; verify floor load capacity before installation
Specifications
| Brand | Carbon Smart™ by Finnish Sauna Builders |
| Kit size | 5’ × 8’ × 8’ |
| Wood | Thermo Poplar (thermally modified, no added chemicals) |
| Door rough opening | 28″ × 80″ |
| Bench depth | 20″ |
| Kit weight | 800 lbs |
| Heater options | No Heater, or six Harvia 8kW models (see chart below) |
| Certifications | See individual Harvia heater model specifications |
Shipping and Returns
- Shipping: see our Shipping Policy for delivery windows, method, and full details.
- Returns: 30-day return window; item must be unused and in original packaging. Damage must be reported within 48 hours of delivery. A 25% restocking fee applies to approved returns. See our Return Policy for full details.
Common Questions
What does the kit include?
The Carbon Smart™ kit includes all interior components: T&G wall and ceiling boards, bench boards with supports, corner moldings, all-glass door with hardware, duckboard flooring, vent grills, foil vapor barrier, backrests, headrest, sauna bucket with liner and ladle, thermometer, vapor-proof light, and installation instructions. Framing, insulation, electrical wiring, and exterior wall covering are customer-supplied.
Does the kit include a heater?
A heater is optional. You can select No Heater or choose from six Harvia 8kW models at checkout. Each Harvia heater includes stones; the Virta model also includes a protective railing. Electrical requirements vary by model — refer to each model’s individual specifications.
What electrical work is required?
Electrical requirements depend on the Harvia heater model selected. Refer to the individual Harvia model specifications for voltage, wattage, and dedicated circuit requirements. A licensed electrician should verify your installation meets local electrical codes before use.
What is the return policy?
Serene Lifestyle Co accepts returns within 30 days of delivery. The item must be unused and in its original packaging. Damage must be reported within 48 hours of delivery. A 25% restocking fee applies to approved returns. See our Return Policy for full details.
Sauna Heater Comparison Chart
| Feature | Harvia KIP80B 8KW | Harvia Cilindro PC80 8KW | Harvia KIP80W 8KW | Harvia Cilindro PC80E 8KW | Harvia Spirit 8KW | Harvia Virta 8KW |
|---|---|---|---|---|---|---|
| Product Image |  |
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 |
 |
 |
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| Power Output | 8 KW | 8 KW | 8 KW | 8 KW | 8 KW | 8 KW |
| Control Type | Built-in Control | Built-in Control | WiFi Control | WiFi Control | WiFi Control | WiFi Control |
| WiFi Connectivity | ❌ No | ❌ No | ✅ Yes | ✅ Yes | ✅ Yes | ✅ Yes |
| Heater Stones Included | ✅ Yes | ✅ Yes | ✅ Yes | ✅ Yes | ✅ Yes | ✅ Yes |
| Railing Included | ❌ No | ❌ No | ❌ No | ❌ No | ❌ No | ✅ Yes |
| Brand | Harvia | Harvia | Harvia | Harvia | Harvia | Harvia |
| Model Series | KIP Series | Cilindro Series | KIP Series | Cilindro Series | Spirit Series | Virta Series |
| Model | KIP80B | PC80 | KIP80W | PC80E | Spirit | Virta |
| Remote Control | Manual only | Manual only | App-based via WiFi | App-based via WiFi | App-based via WiFi | App-based via WiFi |
Harvia KIP80B 8KW Built-in Control
Harvia Cilindro PC80 8KW Built-in Control
Harvia KIP80W 8KW WiFi
Harvia Cilindro PC80E 8KW WiFi
Harvia Spirit 8KW WiFi
Harvia Virta 8KW WiFi with Railing
Key Differences Between Heater Models
- All models: 8 KW output, heater stones included
- KIP80B & Cilindro PC80: built-in manual control only, no WiFi
- KIP80W, Cilindro PC80E, Spirit & Virta: WiFi-enabled, app-based control and scheduling
- KIP Series: compact wall-mounted design
- Cilindro Series: cylindrical design with higher stone capacity
- Spirit Series: modern aesthetic with WiFi
- Virta Series: WiFi control plus included protective railing
Safety and Installation Notice
Installation must comply with local building and electrical codes. Electrical requirements vary by heater model; consult a licensed electrician before installation. Verify floor load capacity before placing the assembled kit. Specifications are provided by the manufacturer; verify site requirements before purchase.
The information presented on this page is for general wellness and educational purposes only. Statements regarding products sold by Serene Lifestyle Co have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure, or prevent any disease. Consult a qualified healthcare provider before beginning any new wellness routine, especially if you are pregnant, nursing, or have a pre-existing medical condition.
