“I’d been looking for a replacement unit for some time (mostly the foam variety) as was thrilled when I came across this beauty”

“I wanted to share that we LOVE our new thrml. hot tub cover!”

“This will be revolutionary”

“I’m so excited to see how well our thrml. cover not just survive, but stand up to all that comes its way”

AIRCAP 1™ replacement hot tub cover by thrml. Unbox.
Inflate.
Zip.

No foam core to soak up water. Fits square spas 77″–94″. $1,195 with free shipping.

Find your size in seconds

Type your hot tub brand and model, or the measurement across the top.

Brand and model, or the measurement across the top of your spa

Covers the current models of every major brand. Not listed? Use the two-step measuring guide or browse by brand.

Find your fit Buy now

Prefer to shop locally? Find a retailer.

Free shipping to all 50 states · 30-day returns · 3-year limited warranty · In 100+ hot tub showrooms

AIRCAP 1 hot tub cover on a square spa in a backyard patio

AIRCAP 1™Made for a lighter lift.

What customers are saying

I’d been looking for a replacement unit for some time (mostly the foam variety) as was thrilled when I came across this beauty

thrml. customer

01 / 04

A different kind of hot tub cover

What is AIRCAP 1?

A lighter way to cover your hot tub, built to avoid the familiar problems of waterlogged foam.

Traditional hot tub covers rely on foam cores that absorb moisture, grow heavy and lose their shape over time. AIRCAP 1™ replaces the foam with rigid AirLoc™ drop-stitch construction, the same technology used in inflatable paddleboards. Thousands of internal threads hold the inflated panels flat and firm while keeping the cover easy to handle.

Weighing your options? Compare every alternative to a foam cover.

Explore AIRCAP technology

Filmed at Southern Leisure Spas & Wellness in Texas, one of our authorized showrooms: folding back onto a standard cover lifter and closing again. It works with most cover lifters. Not sure about yours? Ask us.

Thoughtfully engineered

Built to solve the
problems of foam.

Four practical reasons to rethink your next hot tub cover.

Water-resistant & lightweight

AirLoc™ panels have no foam core to soak up water, so the cover weighs the same out of the box and years later: 35–40 lb, depending on size.

Learn about water resistance

Designed for durability

Welded drop-stitch panels resist punctures, tears and UV, and hold their shape under pressure, season after season.

Explore AIRCAP durability

Consistent insulation

The sealed AirLoc™ air core has nothing in it to absorb water, so its insulation stays consistent for the life of the cover.

See how AIRCAP insulates

Replaceable skirt system

Three ZipTech™ skirt depths come in the box, and a worn or damaged skirt can be replaced on its own, without replacing the whole cover.

See how ZipTech works

Let’s get the size right

Find the right AIRCAP
for your hot tub.

Six cover sizes with interchangeable skirt lengths. Choose the path that works for you.

Spa Fitter™

Know your spa
brand and model?

Type your brand and model to see its dimensions and your AIRCAP 1™ size.

Know your spa brand and model?

Type your brand and model to see its dimensions and your AIRCAP 1™ size.

Brand and model, or the measurement across the top of your spa

Covers the current models of every major brand. Not listed? Use the two-step measuring guide or browse by brand.

Browse all brands

SureFit™

Prefer to measure
your spa?

Measure straight across the top of your spa, edge to edge, both ways, in inches.

Need the full guide? Open SureFit™

Need help? Contact thrml. to confirm your fit before you order.

Six sizes. One smarter cover.

Choose your AIRCAP 1 size.

For square spas from 77 to 94 inches. Use Spa Fitter™ or SureFit™ before ordering to confirm your size.

The AIRCAP 1 shipping box delivered to a front door

Ships free to your door

XXS 77–79 in $1,195Buy now XS 80–82 in $1,195Buy now Small 83–85 in $1,195Buy now Medium 86–88 in $1,195Buy now Large 89–91 in $1,195Buy now X-Large 92–94 in $1,195Buy now

Not sure which size you need? Find by brand and model Find by measurements Contact support

Every detail matters

Purchase with confidence.

30-day returns

Wrong size or changed your mind? Swap it or return it within 30 days, with no restocking fee. Return shipping is paid by the buyer.

How the fit guarantee works

3-year warranty

Backed by a three-year limited warranty against manufacturing defects.

Warranty details

Fit assistance

Use Spa Fitter™ or SureFit™, or contact us before you order and we will confirm your size.

Your cover. Your way.

Buy AIRCAP your way.

Shop online

From our door
to yours.

Ships free to all 50 states, usually within 1–2 business days, then 3–5 business days in transit (a few days longer to Alaska and Hawaii).

Shipping details

Buy now

Shop local

See it in
person.

Feel the weight and check the fit on a real spa at an authorized showroom.

Available in over 100 authorized hot tub showrooms across 32 states.

Find a retailer

Stay in the loop

Get more from
your hot tub.

Product updates, care advice, fit guidance and occasional offers from thrml.

Marketing emails are optional. You can unsubscribe at any time.

For retail partners

Bring AIRCAP to
your customers.

Offer hot tub owners a modern alternative to traditional foam replacement covers.

Become a retailer Already a partner? Visit the retailer portal