Quick answer: Choose the Sunlighten Signature I if you want a compact one-person far-infrared cabin, a dedicated 120V/20A circuit, eucalyptus construction, and a guided Sunlighten ownership experience. Choose the Clearlight Premier IS-1 if you want a slightly wider bench, a shallower electrical requirement on the current US specification, and a lighter cabin that plugs into a 120V/15A outlet. Neither is universally better: the right choice depends on room dimensions, circuit capacity, bench comfort, delivery access, warranty terms, and how much installation support you want. We did not physically test either sauna; this comparison uses official US product information reviewed October 28, 2026.
Sunlighten vs Clearlight at a glance
- Sunlighten Signature I: 37.8 inches wide, 39.8 inches deep, 77.7 inches high; 428 pounds; 32.1-by-20.2-inch bench; 120V, 1,350W, 20A, NEMA 5-20; far-infrared heaters; eucalyptus construction.
- Clearlight Premier IS-1: 40 inches wide, 44 inches deep, 76 inches high; 325 pounds; 33-by-22-inch bench; 120V, 1,370W, 11.42A, NEMA 5-15P on the current US product page; far-infrared heaters; available wood details should be confirmed on the quote.
- Choose Sunlighten for: the narrowest footprint, a taller interior, eucalyptus finish, and buyers comfortable planning a dedicated 20A circuit.
- Choose Clearlight for: a wider and deeper bench, lower published amperage, lighter panel set, and a standard 15A outlet configuration.
- Consider a custom alternative when: neither standard cabin fits your room, preferred recline, accessibility needs, or outdoor plan. Explore SaunaCloud custom infrared sauna options (paid link).
How we compared these two saunas
This is a buyer-fit comparison, not a laboratory performance ranking. We compared the exact one-person far-infrared models on measurable installation and ownership criteria: exterior and interior dimensions, bench size, total weight, electrical requirements, heater format, delivery method, assembly, published clearances, controls, warranty language, and service questions. We excluded medical promises and did not repeat unverifiable claims about detoxification, calorie burn, disease treatment, or guaranteed recovery.
Manufacturer documentation can change. Before paying a deposit or scheduling electrical work, ask for the current model-specific manual, specification sheet, plug drawing, delivery terms, and written warranty. The quote and manual for the exact unit you receive should control over any comparison article.
Cabin size and room fit
Sunlighten Signature I
The Signature I is the narrower cabin. Sunlighten lists a 37.8-inch width, 39.8-inch depth, and 77.7-inch height including two-inch feet. The company recommends four inches between the sauna and surrounding walls and another 12 inches above it. The door opening is listed at 28 inches and swings outward to the right. Those clearance details matter more than the cabin dimensions alone: confirm the finished room width, ceiling height, door swing, baseboard projection, and access to the outlet.
The interior measures 32.2 inches wide, 33.6 inches deep, and 70.3 inches high. A tall user should compare seated headroom and knee position, not just overall cabin height.
Clearlight Premier IS-1
Clearlight lists the Premier IS-1 at 40 inches wide, 44 inches deep, and 76 inches high, with four inches of clearance recommended around the cabin when installed in an enclosed space. The interior is 35 inches wide, 40 inches deep, and 71 inches high. It takes slightly more floor area than the Signature I but provides more interior width and depth.
Neither cabin should be squeezed into a space that blocks ventilation, prevents a hard reset at the receptacle, or makes panel service impossible. Measure the room after accounting for flooring transitions, trim, sloped ceilings, and furniture—not from an empty floor plan.
Bench comfort: the deciding measurement many buyers miss
Sunlighten lists the Signature I bench at 32.1 inches wide, 20.2 inches deep, and 19.5 inches above the floor. Clearlight lists the Premier IS-1 bench at 33 inches wide, 22 inches deep, and 17.5 inches high. The numerical difference looks small, but seat depth and height affect thigh support, knee angle, and the ability to shift position during a session.
The Clearlight bench is approximately 1.8 inches deeper and two inches lower based on the current published figures. The Sunlighten bench is slightly narrower and higher. Neither is a reclining bench. If you want to stretch out, elevate your legs, or share the cabin occasionally, a one-person model may be the wrong format even when its exterior fits.
Use our infrared sauna bench-dimensions checklist before ordering. Mark the bench dimensions on a chair or cardboard template and sit for ten minutes. That simple test is more useful than relying on a “one person” label.
Electrical requirements
Signature I: dedicated 120V/20A
Sunlighten’s current US store page lists 120V, 1,350W, 20A, a NEMA 5-20R receptacle, and NEMA 5-20P plug. It specifically calls for a dedicated 20A circuit and outlet. A NEMA 5-20 receptacle has a different slot pattern from a typical 15A outlet, so do not assume that an existing bedroom or bathroom receptacle is ready.
Premier IS-1: 120V/15A configuration
Clearlight’s current US product page lists 120V, 1,370W, 11.42A and a NEMA 5-15P plug, while its electrical-requirements page assigns the Premier 1 to a 120V/15A circuit. Optional full-spectrum or red-light upgrades can increase circuit requirements on some Clearlight models, so the base-cabin specification must not be reused for an upgraded quote.
For either sauna, have a qualified electrician confirm circuit capacity, receptacle condition, GFCI requirements where applicable, cord routing, and local code. Do not use an extension cord or adapter unless the manufacturer’s current manual explicitly permits it.
Heat system and controls
The Signature I is a far-infrared model using Sunlighten’s SoloCarbon heater system. It is positioned as the simpler Sunlighten cabin rather than the company’s multi-wavelength mPulse line. Clearlight’s Premier IS-1 is also a far-infrared model, with True Wave carbon-and-ceramic heaters listed on the front, back, side, calf, and floor zones.
Heater brand names alone do not tell you how a sauna will feel. Ask each seller for heater placement diagrams, maximum controller setting, warm-up guidance for your climate, independent electrical documentation, replacement-part coverage, and whether controls can be serviced without dismantling the cabin. If integrated red light is a priority rather than an accessory, compare SaunaCloud’s current integrated sauna configurations (paid link) against the exact distance and layout you want.
Delivery and assembly
Sunlighten states that the Signature I arrives in two to three large panel boxes, each weighing about 130 pounds, with pallet delivery to a flat paved area such as a garage or driveway. The brand advises having at least two people available to unpack and assemble the panels in the final room. Delivery does not mean upstairs placement.
Clearlight states that smaller cabins can be assembled by two people in roughly one to three hours and that professional installation may be available in some markets. Confirm whether your quote includes curbside freight, threshold service, room-of-choice delivery, assembly, debris removal, and damage inspection. Photograph the crate before opening and note freight damage on the carrier record.
Our infrared sauna delivery checklist covers doorways, stairs, ceiling height, floor protection, crate inspection, and electrician timing.
Wood, weight, and floor planning
Sunlighten lists eucalyptus construction and a total Signature I weight of 428 pounds. Clearlight lists the Premier IS-1 at 325 pounds. Add the user’s weight and any accessories when considering the finished load. Ground-level concrete or properly supported residential floors may be straightforward, but upper floors, older structures, and concentrated loads deserve professional review when uncertain.
Wood preference is personal. Ask about solid wood versus veneers or engineered panels, interior finishes, adhesives, cleaning restrictions, aroma sensitivity, replacement slats, and how the warranty treats checking, discoloration, or natural grain variation. Do not choose on the word “premium” alone.
Warranty and service questions
Both brands promote residential warranty coverage, but the useful comparison is the current written document: which components are covered, for how long, whether labor is included, who pays shipping, what happens outside a service area, and which maintenance failures or modifications are excluded. A lifetime label can still contain component-specific limits and owner costs.
- Ask whether heaters, controls, wiring, glass, cabinetry, lighting, audio, and labor have different terms.
- Confirm whether using a non-dedicated circuit, extension cord, aftermarket accessory, or unapproved cleaner affects coverage.
- Ask who diagnoses a problem and whether remote troubleshooting is required before parts are shipped.
- Verify freight responsibility for large replacement panels or glass.
- Keep the invoice, serial number, electrical receipt, delivery photos, and maintenance records.
Use our infrared sauna warranty checklist to compare the two written offers line by line.
Who should buy the Sunlighten Signature I?
Choose the Signature I if the 37.8-inch width solves a real space constraint, you like the eucalyptus cabin, the 20.2-inch bench depth works for your body, and installing a dedicated 20A receptacle is practical. It also suits a buyer who prefers a guided Sunlighten quote and service path and does not need the feature set of the more expensive mPulse line.
Potential drawbacks: the dedicated 20A circuit can add electrical cost; the cabin is heavier; the bench is slightly narrower and shallower than the Clearlight bench; pricing and delivery scope should be confirmed in writing.
Who should buy the Clearlight Premier IS-1?
Choose the Premier IS-1 if you value the wider, deeper bench, prefer the published 15A base electrical configuration, and want a lighter panel set. It is a sensible fit for buyers focused on a straightforward far-infrared cabin without paying for full-spectrum features they may not use.
Potential drawbacks: the exterior is wider and deeper; optional upgrades may change the electrical requirement; warranty and installation promises should be verified on the actual quote rather than inferred from general marketing.
Buying checklist
- Measure the final room, door swing, ceiling, route, stairs, and largest access point.
- Confirm the exact bench dimensions against your seated posture.
- Get the current electrical sheet before scheduling an electrician.
- Compare delivered-and-installed totals, not cabin price alone.
- Read the complete warranty and return policy before opening packaging.
- Confirm cleaning products, ventilation, service access, and replacement-part process.
- Do not pay for optional light, audio, or app features unless they support a routine you will use.
Frequently asked questions
Which sauna uses less floor space?
The Sunlighten Signature I has the smaller published footprint at 37.8 by 39.8 inches versus 40 by 44 inches for the Clearlight Premier IS-1. Required clearances still need to be added.
Which sauna has the larger bench?
The Clearlight bench is listed at 33 by 22 inches versus 32.1 by 20.2 inches for the Sunlighten bench.
Can both use a regular household outlet?
Both are 120V, but the requirements differ. The Signature I calls for a dedicated 20A NEMA 5-20 circuit. The Premier IS-1 base model is listed for 120V/15A with a NEMA 5-15P plug. Verify the exact current model and options.
Is full spectrum automatically better than far infrared?
No. It is a different feature set, not automatic proof of a better purchase. Choose by your intended use, published output, installation needs, controls, warranty, and budget.
What if neither standard cabin fits?
A custom sauna may be more appropriate for unusual rooms, outdoor placement, specific bench geometry, or design integration. Compare drawings, power, materials, delivery, and installed cost before committing.
Verdict
The Sunlighten Signature I is the better match for the narrowest one-person footprint and buyers comfortable with a dedicated 20A circuit. The Clearlight Premier IS-1 is the better match for a wider bench, lighter cabin, and base 15A configuration. If your decision is constrained by a nonstandard room or you want an integrated custom layout instead of choosing between two prefab boxes, request current SaunaCloud design and installation information (paid link).
Affiliate disclosure: BeautyTech Hub may earn a commission from qualifying purchases made through sponsored links, at no extra cost to you. Sunlighten and Clearlight source links are informational; SaunaCloud links are sponsored. We did not physically test these saunas.
