40th of 59 in Saunas

Sunlighten Amplify IV Full Spectrum Infrared Sauna

Full spectrum infrared
4 people
Up to 161-175°F
240V plug-in

SVT Score, Mid

Usability6.6/10Social3.5/10The SVT Score is placed on its category's range

Versus

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A four-person indoor full spectrum cabin in eucalyptus with a reclining bench, rated to 170°F, on a 240 V circuit.

$8,999

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SKU: SL-AMPLIFY-4 Category: Saunas Brand: Sunlighten

Usability

6.6 out of 10

Temperature9rated to 170°F in ideal conditions by the maker

Heating / Cooling Power78 far infrared and 4 full spectrum heaters, 3,900 W, four seats

Capacity7four seats

Build & Insulation6solid eucalyptus, walls 1.8 to 2.2 in thick, thick insulation stated, fabric heater covers

Size: 80.4 by 56.2 by 77.7 in outside, about 921 lb
Glass: double-pane door, not stated as tempered

Features & Water Care6app control, chromotherapy light, Bluetooth audio, timer with reservation mode

Not included: an adjustable vent and a backrest (backrests sold separately)

Verification6Intertek lists the Amplify 4 room to UL 875 and CSA 164; no second independent lab record.

Searched: Intertek CSA UL CPSC Health Canada
Record: Intertek ETL, UL 875 (Electric Dry Bath Heater; ETL Listed Mark; edition not printed), Dry Wooden Sauna Room, Model Nos. ... Amplify 4 (listing text: Trade Name(s): Sunlighten. Dry Bath Sauna Cabinet, Model No. Solo Sauna. Dry Wooden Sauna Room, Sunlighten, Model Nos. Aspire, Believe, Conquer, Discover, Empower. Dry Wooden Sauna Room, Model Nos. Signature Restore, Signature Renew, Signature Revive, Amplify 2, Amplify 3, Amplify 4. Control & Heater System For Dry Custom Sauna, Model Nos. CS-160, CS-420, CS-960, CS-1440, CS-1920), SUNLIGHTEN, INC. - Overland Park, KS USA
Record: Intertek ETL, CAN/CSA-C22.2 No. 164 (Electric Sauna Heating Equipment; cETL Listed Mark), Dry Wooden Sauna Room, Model Nos. ... Amplify 4, SUNLIGHTEN, INC. - Overland Park, KS USA

Warranty & Support5heaters seven years, controls three years, replacement parts only with no labour

Returns: 30 days, unopened only, less a $499 restocking fee and a 3% fee

Strengths

Full spectrum infrared heat with halogen heaters
Room for four with a large reclining bench
Double-pane glass and stated insulation
App control plus Bluetooth audio

Drawbacks

Less heater output for each seat than smaller sizes
Very heavy to move and assemble
Parts-only warranty with no labour cover
Store pages make wellness claims we do not assess
Needs a higher-voltage outlet wired by an electrician

Verdict

A hot, roomy cabin for four, but heavy and needs 240 V

Social score

3.5 out of 10

RedditBrand-level3 out of 10

r/infraredsauna: an owner warns against buying after support confirmed a defective unit following hours of calls (2026)
r/infraredsauna: a shopper close to buying held off over owners' reports of poor service after the sale (Jun 2026)

Google4 out of 10

Brand-level. sauna.guide confirms two BBB complaints of a cabin glass door shattering in October and November 2025 and counts 46 BBB complaints in three years; it traces no source for a 5 to 15 mG EMF rumour (Oct 2026)

YouTubeNot scored

The YouTube pool is blank: a web search in November 2026 turned up Sunlighten videos only from testers with affiliate links or a brand tie, and one comparison whose independence is unclear (November 2026).

AmazonNot scored

The Amazon pool is blank: No Sunlighten store or listing was found on Amazon US in November 2026; Amazon search pages send shoppers to the brand's own store (November 2026).

User reviewsNot scored

No listing of these saunas was found at Walmart, Home Depot, Lowe's, Best Buy or REI in November 2026, so the retailer pool is blank.

Trustpilot

Trustpilot shows 4.6 from 4,092 reviews in October 2026, with 86% five-star and 6% one-star.
Sunlighten has claimed its Trustpilot page and invites customers to review.

Track record

BBB rates Sunlighten A+ and has accredited it since 2004.
BBB lists 48 grievances filed in the three years to October 2026.
A search of CPSC and Health Canada recall notices in November 2026 showed no Sunlighten sauna recall.

Not countedExcluded

Not counted in any pool: Sunlighten's own store and Trustpilot product reviews, its own channels and social pages, and testers it supplied or who carry its discount codes.
The retailer pool is blank: a web search of Walmart, Home Depot, Lowe's, Best Buy and REI turned up no listing of this sauna (November 2026).

Specs

TypeInfrared
HeaterFull spectrum infrared
FormCabin
PlacementIndoor
Seats4 people
Max Temperature161-175°F
Min TemperatureNot applicable
Capacity (Gallons)Not applicable
ChillerNot applicable
HeatsNot applicable
Water CareNot applicable
Power Supply240V plug-in
EMF ClaimedUnder 1 mG
EMF MeasuredNot measured
CertificationsCSA C22.2 No. 164 listed, UL 875 listed
Warranty3 Years

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At a glance

Two benches inside
No floor heater
Magnetic-lock panels

Company

The company is based in Leawood, Kansas, and was founded in 1999.
Sunlighten bought the assets of a cold-plunge maker in May 2025 and runs them as its subsidiary Ice Barrel, LLC.
That subsidiary's own store also sells the Amplify line.

Where it sells

Sunlighten, Inc. sells saunas from a one-person dome to four-person full spectrum cabins on its own US store, shop-us.sunlighten.com.
Its mPulse cabins are sold through sauna consultants without a priced cart.
No Sunlighten store or listing was found on Amazon US in November 2026.

Description

The Sunlighten Amplify IV is a four-person indoor full spectrum infrared cabin in eucalyptus with eight SoloCarbon far infrared panels and four full spectrum halogen heaters. The spec sheet gives 3,900 W in total, and it needs a dedicated 240 V 20 A circuit with a NEMA 6-20 outlet.

The brand rates it to 170°F "in ideal conditions", and the manual says the preset is the maximum setting. It measures 80.4 by 56.2 by 77.7 inches outside and 74.8 by 50 by 70.3 inches inside, and weighs about 921 lb.

A double-pane glass door, fabric heater covers, chromotherapy lights, a Bluetooth receiver, app control, a timer and a reservation mode come with it. Backrests, cushions and comfort packages are sold separately.