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Our one-person cabin pick

Sunlighten Signature I

1-person installed far-infrared cabin, eucalyptus

$4,999US price, checked Oct 13, 2026

One-person far-infrared cabin that needs its own 120 V, 20 A circuit

Check price at Sunlighten Full review →

Installed infrared cabin

Sunlighten Amplify III

3-person installed infrared cabin, eucalyptus/obsidian

$6,999US price, checked Oct 13, 2026

Three-person cabin with ten heaters on a dedicated 120 V circuit

Check price at Sunlighten Full review →

Criterion	Sunlighten Signature I	Sunlighten Amplify III
US price	$4,999Checked Oct 13, 2026 · Price details in the review	$6,999Checked Oct 13, 2026 · Price details in the review
Three-year ownership estimate	$5,371.52 Incomplete known subtotal. Electricity assumption: $0.18/kWh. Not included: installation.	$6,999 Incomplete known subtotal. Not included: installation, energy use.
Choose if	One person with a dedicated 120 V, 20 A circuit and about 38 × 40 in of indoor floor.	Two or three people who share sessions, with a dedicated 120 V, 20 A circuit and about 63 × 46 in of indoor floor.
Main trade-off	You can't return it once the boxes are opened, and the warranty doesn't pay for labor.	Opened saunas can't be returned, and the product page skips wattage, top temperature and a safety listing number.
Key specifications	Heaters: 8 far-infrared heaters, with Sunlighten's SoloCarbon heater named as a feature. No near-infrared or full-spectrum heaters are listed, and per-heater wattage isn't stated Electrical: 120 V, 1,350 W, 20 A. Dedicated 120 V, 20 A circuit with a NEMA 5-20R outlet (5-20P plug) Inside and seating: 32.2 W × 33.6 D × 70.3 H in. One bench, 32.1 W × 20.2 D in and 19.5 in high, for one person Outside and weight: 37.8 W × 39.8 D × 77.7 H in with feet, 428 lb. Leave 4 in to the walls and 12 in above Heat: Up to 170°F. Sunlighten suggests preheating for 45 to 60 minutes and says it warms about 1°F per minute Delivery and assembly: Freight to a garage or flat, paved driveway, left on a pallet. Two people assemble it in about 2 to 3 hours Running cost: Sunlighten estimates 15 to 35 cents an hour Extras: Bluetooth sound system, chromotherapy lights, CELLIANT heater cover and a Reservation Mode that starts the preheat	Heaters: 7 SoloCarbon far-infrared heaters and 3 halogen full-spectrum heaters. Wattage of each isn't stated Electrical: 120 V on a dedicated 20 A circuit and outlet. Wattage, amperage and outlet type aren't on the product page Inside and seating: 56.8 W × 39.9 D × 70.3 H in. One bench, 56.7 W × 20.3 D in and 19.5 in high, for up to three people Weight: 642 lb Delivery and assembly: Freight to a flat, paved surface at your garage door, left on a pallet. Two people assemble it in about 2 to 3 hours Heat-up: Sunlighten suggests preheating for 45 to 60 minutes and says it warms about one degree per minute Options: Eucalyptus or Obsidian at the same price, basswood $200 less. The 2-person size costs $1,000 less. Integrated red light was marked not available Extras: Bluetooth sound system, chromotherapy lights and a CELLIANT heater cover
Exact variant	1-person installed far-infrared cabin, eucalyptus	3-person installed infrared cabin, eucalyptus/obsidian
Dimensions	Outside: 37.8 W × 39.8 D × 77.7 H in, including 2 in feet. Inside: 32.2 W × 33.6 D × 70.3 H in. The door opening is 28 in, and the door swings outward to the right. The bench is 32.1 in wide and 20.2 in deep, 19.5 in off the floor. It weighs 428 lb. Sunlighten recommends 4 in of clearance from the walls and 12 in above the cabin. It says the cabin fits under a standard 8 ft ceiling and its panels fit through a standard 30 in doorway.	Outside: 62.3 W × 45.9 D × 77.7 H in, including 2 in feet. Inside: 56.8 W × 39.9 D × 70.3 H in. The door opening is 28 in. The bench is 56.7 in wide and 20.3 in deep, 19.5 in off the floor. It weighs 642 lb. Sunlighten says it fits under a standard 8 ft ceiling and its panels fit through a standard 30 in doorway. The product page gives no clearance to leave around the cabin.
Installation	It needs a dedicated 120 V, 20 A circuit and outlet. The outlet is a NEMA 5-20R, and the plug is a NEMA 5-20P. Sunlighten's FAQ says a power strip or converter voids the warranty. The warranty page also rules out extension cords and non-dedicated circuits. The same page requires at least 5 ft between the sauna and a cold plunge, shower or bathtub. The product page doesn't say whether you need an electrician or GFCI protection. It points you to the spec sheet for electrical details. Sunlighten's support page links an owner's manual, spec sheet, assembly guide and power box installation guide. Those PDFs couldn't be opened for this review. Freight delivery goes to a garage or flat, paved driveway. The carrier leaves the sauna there on a pallet and can't carry it up steps. It comes in two to three mattress-sized boxes of 130 lb each, and you need at least two people to unpack and carry in the panels. The Magne-Seal panels lock together without screws or nails. Sunlighten says two people take about 2 to 3 hours.	It needs a dedicated 120 V, 20 A circuit and outlet. Sunlighten's FAQ says a power strip or converter voids the warranty. The warranty page also rules out extension cords and shared circuits. It asks for at least 5 ft between the sauna and a cold plunge, shower or bathtub. The product page suggests booking an electrician so the outlet is ready on build day. It doesn't list the wattage, amperage or outlet type. Freight delivery needs a flat, paved surface up to your garage door. The carrier leaves the sauna there on a pallet and can't carry it up steps. It comes in two to three mattress-sized boxes of 130 lb each. The Magne-Seal panels lock together without screws or nails. Sunlighten says two people take about 2 to 3 hours.
Materials	Eucalyptus, which Sunlighten says is sustainably sourced, with natural variation in tone and grain. Basswood was marked not available, and the Obsidian finish is sold on a separate page. It comes with a CELLIANT heater cover. Sunlighten says the glue is non-toxic, citing third-party testing by Franklin International.	It's eucalyptus in Sunlighten's black Obsidian finish. Plain eucalyptus costs the same, and basswood is $200 less. It comes with a CELLIANT heater cover. Sunlighten says its eucalyptus is sustainably sourced. It also says the glue on the tongue-and-groove boards is non-toxic and was third-party tested by Franklin International.
Warranty	Sunlighten's warranty page covers its mPulse, Signature and Amplify cabins under one set of terms. For home use, the cabinet and heaters get 7 years. The cabinet includes the bench, floor grates and heater cover frames. The controls (in-sauna tablet, control pad and power box) get 3 years. The glass door and audio get 1 year, and chromotherapy has a separate 1-year warranty. Commercial use gets 5 years on the cabinet and heaters and 1 year on everything else. It covers replacement parts only, not labor or technician costs. You pay the freight on parts shipped for service. It covers only the original buyer and ends if you sell the sauna. It's void on a power strip, extension cord, converter or non-dedicated circuit. It's also void within 5 ft of a shower, tub or cold plunge. Sunlighten's contraindications page adds that repairs attempted without consulting Sunlighten void it. Sunlighten says its saunas aren't designed for outdoor use. Outside, the separately sold sauna cover has to stay on at all times, even during sessions. The sauna must also be bought and put into use within a year of its manufacture date. The page shows no version or effective date.	Sunlighten's warranty page groups Amplify with its other cabin saunas. For home use, the cabinet and heaters get 7 years, the controls 3 years, and the glass door and audio 1 year. Commercial use gets 5 years on the cabinet and heaters and 1 year on everything else. You pay the freight on parts shipped for service. A general disclaimer says coverage is for replacement parts only, not labor or technician costs. It sits right after the red light panel's terms, so it's unclear whether it applies to cabins. The warranty covers only the original buyer and ends if you sell the sauna. It's void on a power strip, extension cord, converter or shared circuit, or within 5 ft of water. Sunlighten says its saunas aren't designed to be placed outdoors. If you put one outside anyway, its cover (sold separately) has to stay on at all times, even during sessions. The sauna must also be bought and put into use within a year of its manufacture date. The page shows no version or effective date.
Returns	You can return or exchange it within 30 days of delivery, but only in the original, unopened packaging. Opened saunas can't be returned. Charges can include a 3% administrative fee, a $499 restocking fee for Signature saunas, storage fees and return shipping. You can cancel before it ships, but the same fees can apply. You start a return by emailing your sales rep or customer care for an authorization, and Sunlighten schedules the pickup. It refunds to your original payment method after it inspects and restocks the sauna. Sunlighten reserves the right to refuse a return, exchange or cancellation.	Non-custom saunas like Amplify can be returned or exchanged within 30 days of delivery, but only in the original, unopened packaging. Opened saunas can't be returned or exchanged. Charges can include a 3% administrative fee, a $499 restocking fee, storage fees and return shipping to the warehouse. Cancelling before it ships can cost the 3% fee, plus storage fees if the sauna has to be re-routed. Sunlighten reserves the right to refuse a return, exchange or cancellation. It refunds to your original payment method after it inspects and restocks the sauna.
Unresolved questions	Whether an ETL listing covers Signature I, and its file number What the linked EMF test measured, on which models and at what distance Whether you need GFCI protection or a licensed electrician for the circuit What the owner's manual, spec sheet and power box installation guide require, since those PDFs couldn't be opened Average power draw once the cabin is up to temperature Carton weights, since two to three boxes of 130 lb each don't add up to 428 lb How many cleanings one $39 cleaning kit covers Whether the $4,999 sale price lasts past the October 14 event	The cabin's rated wattage and amperage, and so its running cost The maximum cabin temperature Which outlet type it needs and whether GFCI protection is required How much clearance to leave around the cabin Whether the warranty's no-labor line covers cabin saunas or only the red light panel What the owner's manual and power box installation guide require, since those PDFs couldn't be opened Whether an ETL listing covers this exact model, and its file number What the linked EMF test measured, on which models and at what distance Carton weights, since two to three boxes of 130 lb each don't add up to 642 lb Whether the $6,999 sale price outlasts the October 14 event

These comparisons use published specifications, not head-to-head tests. Prices and terms are dated. Unknown costs are not zero. Check the exact variant before you buy.