The THRML Spa Cover Hub
Foam-free covers, honestly reviewed — by Colorado's top-ranked AIRCAP 1 dealer. Expert guides, real comparisons, and answers from 50 years of spa service.
THRML is the engineering company behind the AIRCAP 1™ — the foam-free spa cover that solves the problem that kills every traditional cover: water absorption. Instead of foam, the AIRCAP 1 uses sealed air-core chambers that can't soak up water, so the cover weighs the same and insulates the same on the day it's retired as the day it was installed.
Carefree Spas is one of THRML's top-ranked dealers nationally — our Littleton showroom stocks the AIRCAP 1 in the six standard spa sizes, backed by a 3-year warranty, and we ship to all 50 states. We've spent years answering Colorado owners' cover questions — snow loads, wind, waterlogging, energy bills — and this hub collects everything we've learned in one place.
Zero Water Absorption
Traditional foam covers gain weight and lose R-value as steam saturates the core. The AIRCAP 1's air-core chambers cannot absorb water — ever. No waterlogging, no ice shell, no sag.
Built for Colorado Winters
Full insulating value through sub-zero nights and heavy spring snow. Brush it off after a storm and it's back to work — no saturated foam, no tear-prone ice sheet.
In Stock, Locally Backed
$995 at our Littleton showroom in six standard sizes, with a 3-year warranty. Ships to all 50 states. Questions? Real people answer at (303) 321-9600.
Expert Guides in This Series
THRML AIRCAP 1™ Spa Cover Review
Our honest, hands-on review of the foam-free cover Colorado owners keep asking about — weight, R-value, warranty, and who it's right for.
Read the guide
Spa Cover Care: Extending the Life of Your Cover
The care routine that adds years to any cover — and how to know when replacement becomes the smarter buy.
Read the guide
5 Ways to Cut Your Hot Tub's Energy Bill
Your cover is the biggest lever on your heating bill. Here's the math — and the five fixes that matter most.
Read the guideFrequently Asked Questions
What is the THRML AIRCAP 1™ spa cover?
It's a foam-free spa cover that replaces the traditional foam core with sealed air-core chambers. Because air chambers can't absorb water, the cover never waterlogs, never gains weight, and never loses its insulating R-value — the three failures that end a traditional foam cover's life in 3–5 years.
How much does the AIRCAP 1™ cost?
$995 at Carefree Spas in Littleton, Colorado — in stock in the six standard spa cover sizes, with a 3-year warranty. Shipping is available to all 50 states. Compare that to replacing a foam cover every few years and it's usually the last cover a spa owner buys.
Is the AIRCAP 1™ cover made in the USA?
The AIRCAP 1™ is engineered by THRML and sold through authorized dealers like Carefree Spas. (Our Aspen Spas hot tubs are the 100% USA-made products in our lineup.) Ask us in the showroom about the cover's construction details — we're happy to walk you through exactly what you're buying.
Where can I buy an AIRCAP 1™ cover near Denver?
At Carefree Spas — 3736 Norwood Drive Unit 1, Littleton, CO 80125, open 7 days a week 10am–5pm. We're one of THRML's top-ranked dealers nationally, we stock the six standard sizes locally, and we ship nationwide. Call (303) 321-9600 to confirm your size.
Ready for the Last Cover You'll Ever Buy?
The THRML AIRCAP 1™ foam-free spa cover — $995, in stock in six standard sizes at our Littleton showroom, with a 3-year warranty and nationwide shipping.