AIRCAP 1™ Large (Fits 89"-91" Spas) Deep Grey™

Name: AIRCAP 1™ Large (Fits 89"-91" Spas) Deep Grey™
Brand: thrml.
SKU: AC6003
Price: 1195.00 USD
Availability: InStock

$1,195.00 USD

Includes the pump, three Ziptech™ skirt depths and four keyed locking tie-down straps.

Free U.S. shipping — shipping policy.

All sizes

XX-Small · 77″–79″ X-Small · 80″–82″ Small · 83″–85″ Medium · 86″–88″ Large · 89″–91″ X-Large · 92″–94″

Not sure which size? Measure with SureFit™ · Warranty

Still weighing foam against foam-free? Every hot tub cover alternative, compared.

✓ Free shipping: ships in 1–2 business days, usually arrives 3–5 business days after that
✓ 3-year warranty · Secure checkout

Available in over 100 authorized hot tub showrooms across 32 states. Want to feel the weight and check the fit first? Find a dealer near you.

The AIRCAP 1™ Large is a foam-free replacement hot tub cover for square spas that measure 89" to 91" on the longer side (such as a 90" x 90" spa); sides differing by up to 1" still count as square. It uses welded drop-stitch air panels with AirLoc™ insulation and no foam, so it weighs 35 to 40 lb, never absorbs water and holds that weight for life; one person can handle it. Color Deep Grey™. Engineered to comply with ASTM F1346-23. Not for rectangular, round or oversize spas.

This is the third largest group on the Spa Fitter, after the Small and the X-Large: 193 models across 36 brands. Jacuzzi's larger square models land here: the J-375, J-385, J-475, J-485, J-575 and J-585 at 91", the J-275 and J-280 at 90", and the J-285 at 89". The current J-LX (2020 on) is also 89", but 2019-and-earlier J-LX shells are 84" and take the Small. Artesian Spas' Elite Dove Canyon and Piper Glen and Premium Leisure's LE 850, GO 850 and PR 881 are 91". Beachcomber's Model 380 and 750 and Sundance Spas' Optima 880 and Cameo 880 measure 89", and Passion Spas' Devotion and Admire sit at 90.6".

Size from the longer side. A 91" x 90" shell is square for fit purposes and is a Large. A longer side that falls between two sizes rounds up, so 91.5" takes the X-Large. The cover is made to overhang its band slightly, at 91" as much as at 89", which is how a cover is meant to sit, so a 91" spa stays in the Large rather than moving up. Shipped with the cover: three Ziptech™ modular skirt sizes (zip on the one that fits the cabinet), the pump and four keyed locking tie-down straps. One person can carry this lightweight hot tub cover, inflate it and set it on the spa.

The big US foam-cover sellers' own pages publish dry weights of 35 to 55 lb for custom foam covers, price them at $409 to $570, and say the first sign of failure is the cover getting heavy. The AIRCAP 1 costs more. It is a hot tub cover that doesn't absorb water: the insulation is air held inside welded drop-stitch panels, there is no foam core to saturate, and it does not gain weight of its own. At 35 to 40 lb in year one, it is 35 to 40 lb in year three.

Priced at $1,195, this foam-free hot tub cover has free shipping to all 50 US states and goes out in 1 to 2 business days. 30-day returns, no restocking fee, buyer pays return shipping; 3-year limited warranty. Find your model on the Spa Fitter, the brand-by-brand fit index on thrmltech.com (1073 models across 60 brands), or measure with the SureFit™ guide on the same site. Available in over 100 authorized hot tub showrooms across 32 states.

Product features

Welded drop-stitch construction — the same engineering as a premium inflatable paddleboard
Never absorbs water: no waterlogging, no gradual weight gain, no mid-life sag
Ziptech™ modular skirt system — three skirt sizes included for a custom fit
Engineered to comply with ASTM F1346-23 as a manual safety cover
Patented

Materials and care

Rinse with a garden hose and mild soap; pressure washing is not recommended. Avoid solvents and abrasive cleaners
The cover never absorbs water, so there is no seasonal dry-out — clean and go
Full care and inflation instructions: download the AIRCAP 1™ manual

What's in the box

AIRCAP 1™ cover
Three Ziptech™ skirt sizes
Pump
Four keyed locking tie-down straps

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AIRCAP 1™ Large FAQ

What size hot tub does the AIRCAP 1™ Large fit?

The AIRCAP 1™ Large fits square hot tubs measuring 89"-91" across the top. Measure your spa side to side across the top of the cabinet. If your measurement falls between two sizes, round up — an oversized cover overhangs slightly, which is how a spa cover is meant to sit, while an undersized one will not seal along the edges.

Does the AIRCAP 1 absorb water like a foam cover?

No. The AIRCAP 1 uses an AirLoc air-cell core rather than foam, so it does not absorb water. It will not gain weight or lose insulating value over time the way a waterlogged foam cover does, which is the usual reason a spa cover has to be replaced.

How much does the AIRCAP 1 weigh?

35–40 lb depending on the size, and it stays at that weight: the AirLoc air core cannot absorb water, so there is nothing inside to get heavier. Foam-cover sellers list new covers at 35–55 lb dry, and a waterlogged one is commonly reported at 100 lb or more.

How much does the AIRCAP 1 cost?

The AIRCAP 1 costs $1,195 in every size, including the pump, three Ziptech skirt depths, and tie-down straps. A foam cover typically runs $400–700 and needs replacing every 3–5 years; the AIRCAP 1 has no foam to waterlog.

Does the AIRCAP 1 ship free?

Yes. Shipping is free to all 50 U.S. states, including Alaska and Hawaii. Orders ship in 1–2 business days and typically arrive 3–5 business days after that; Alaska and Hawaii can take a little longer.

Do I need to measure the corner radius of my hot tub?

No. Rigid foam covers need a corner radius; the AIRCAP 1 does not. Two straight measurements across the top of the spa are all that is required.

What warranty comes with the AIRCAP 1?

Three years, or 36 months, from the date of delivery to the original purchaser, against defects in material and workmanship under normal use.

Can I return the cover if it does not fit?

Yes. Returns are accepted within 30 days of purchase, in like-new condition with all original parts included. There is no restocking fee. You are responsible for return shipping; if you request a prepaid label the cost is deducted from your refund. Refunds are normally processed within seven business days of the return arriving. Bought from an authorized retailer? That retailer's return policy applies.

How do I know which AIRCAP 1 size fits my brand of hot tub?

Look your spa up in the Spa Fitter, which lists the current models of every major manufacturer with the AIRCAP 1 size each one takes. If your model is not listed, the SureFit guide walks through the two measurements needed for any hot tub.

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Some of the reviews shown are from related products the merchant grouped with this one.

Awesome product, my kids don't complain about the cover anymore it fits and looks great, set up was super easy and took about 15 min total. Packaging was also great did not need a sharp object to release the AIRCAP and there was no Styrofoam.

My old foam cover had become completely waterlogged and I was tired of buying a new cover every couple years. I purchased the thrml. AIRCAP and the difference is night and day. Super lightweight, will never get waterlogged, and it looks great!

Great customer service still matters, and frankly, not enough companies deliver it anymore\. This company does, and that deserves recognition\.

Nice and lightweight

When I saw this online, I was so excited. For a reasonable price, I can cover my spa with a top that won't get musty. It stays light and easy to move, instead of getting waterlogged and heavy. It looks clean and it fits well. Installation was a breeze and we love it already!

It is incredibly rare these days to experience customer service that actually cares, that responds immediately and goes the extra mile to care for the customer. What this company has created in terms of an original and revolutionary product is nothing short of amazing. Do not wait to buy one. And if you need help, they'll be there every step of the way.

Great fabric. Loved the quick delivery