AIRCAP 1™ Medium (Fits 86"-88" Spas) Deep Grey™

Name: AIRCAP 1™ Medium (Fits 86"-88" Spas) Deep Grey™
Brand: thrml.
SKU: AC6002
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™ Medium is a foam-free replacement hot tub cover for square spas that measure 86" to 88" on the longer side (an 87" x 87" spa, say); sides no more than 1" apart count as square. Welded drop-stitch air construction with AirLoc™ insulation, and no foam, puts it at 35 to 40 lb; it cannot absorb water, so it holds that weight for life, and one person can handle it. Color Deep Grey™. Engineered to comply with ASTM F1346-23. Not for rectangular, round or oversize spas.

If your longer side is 88", the Medium is the right size; the Large starts at 89". The Spa Fitter lists 97 models across 26 brands here, the smallest group of the six. QCA Spas has the most, seventeen, all at 87": today's Diamond, Diamond Deluxe, Ultra and Coral Deluxe, plus older Paradise, Jewel and Performance Series models and the Naples it built for Home Depot. Be Well Canada Spa has fourteen, all on its 87" Original and Premium cabinets (the O500, O600 and O700 models and the P584, P682 and P783). Wellis Spas has eight: its Malaga, Lima, London, Paris, Milan, Monte Bianco and Rental Escape at 86" and the Houston at 85.5". Bullfrog Spas and Superior Wellness have seven each: Bullfrog's A7, A7L, X7 and R7 at 88", and Superior Wellness' Platinum Barcelona and Tokyo at 88" with the Platinum Onyx and Roma at 87". Hot Spring's Vanguard and Aria (and the NXT versions of both) are 87". Bueno Spa's Denver and Vacation measure 86".

Measure both sides and size from the longer one. An 87" x 86" shell is square for fit purposes and is a Medium. If your longer side lands between two sizes, for example 88.5", round up to the Large; the Spa Fitter applies the same rule at the bottom of the band, filing 85.5" shells such as Hydropool's Serenity 5900 and 6800 as Mediums. Every AIRCAP 1 is built to overhang its band slightly, top of the band included, which is how a cover is meant to sit, so a top-of-band 88" spa stays a Medium. The carton holds the cover, the pump, four keyed locking tie-down straps and three Ziptech™ modular skirt sizes, so you zip on the one that fits your cabinet. One person can manage this lightweight hot tub cover from carton to cabinet.

The big US foam-cover sellers' own pages publish dry weights of 35 to 55 lb for custom foam covers, list custom covers as final sale at several of those sellers, and say the first sign of failure is the cover getting heavy. The AIRCAP 1 removes the core: the panels are welded drop-stitch fabric with air inside, so it is a hot tub cover that doesn't absorb water and does not gain weight of its own. That is what keeps it at 35 to 40 lb for the life of the cover, not just on delivery day.

The price of this foam-free hot tub cover is $1,195, with free shipping to all 50 US states and shipment in 1 to 2 business days. Returns within 30 days, no restocking fee (buyer pays return shipping), and a 3-year limited warranty. The Spa Fitter, the brand-by-brand fit index on thrmltech.com, lists 1073 models across 60 brands with the size each takes, and the SureFit™ measuring guide on the same site shows where to put the tape. 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

View full details

AIRCAP 1™ Medium FAQ

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

The AIRCAP 1™ Medium fits square hot tubs measuring 86"-88" 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