The Envelope Just Got Bigger
As a lightweight, technically minded backpacker, if you were looking to rate the overall performance of a sleeping pad, you might define a "performance envelope" consisting of parameters like warmth, weight, comfort, and packed size. A traditional backpacker might also include durability and ease-of-use, but I’d argue these are less important to lightweight hikers. Tradeoffs among these parameters are unavoidable in any pad technology. For example, closed-cell foam pads are generally lighter, but less comfortable and bulkier than self-inflators.
Ryan Gardner tries out the full-length version of the NeoAir
The new Therm-a-Rest NeoAir pad expands the envelope by offering a 2.5 inch thickness for comfort, an extremely compact stored size, and a claimed R-value of R-2.5 for warmth. The NeoAir achieves the comfort and compact size by virtue of its non-self-inflating construction. This itself is not new in pad designs, as companies such as Big Agnes, Exped, and Pacific Outdoor Equipment have had this type of pad for some time. By eliminating or reducing the thickness of the internal insulation, a non-self-inflator can be blown up to a plush, comfortable thickness, and still be deflated to a compact size for packing. The drawback of this kind of construction is that it is difficult to achieve much thermal insulation. If the pad is constructed with large, empty air chambers like the Big Agnes Clearview Pad, convective air currents in the pad will decrease its insulation dramatically. One way around this is to add some down or synthetic high-loft insulation to the inside of the pad chambers, as is done in the Exped Downmats, Pacific Outdoor Equipment Ether Thermo pads, and Big Agnes Insulated Air Core series. By impeding convective currents, this construction adds substantial warmth. But, it adds weight and increases packed bulk. Plus, if down is used, a pump must be used for inflation to avoid trapping moisture from your breath inside the pad.
The NeoAir can be inflated up to 2.5 inches thick. As with other inflatable pads, maximum comfort is achieved at some point slightly less than maximum inflation.
The NeoAir promises to deliver the light weight, simplicity, and compactibility of an insulation-less non-self-inflator like the Clearview Air, with the warmth of an insulated pad. It achieves this with a five-layer honeycomb construction that disrupts convective currents and reflects radiant heat.
Cross section of the NeoAir pad. The honeycomb structure reduces air currents, while the reflective layer in the center reduces radiant heat loss.
Producing this honeycomb structure, dubbed "Core Matrix," required new manufacturing technology. A proprietary machine made in Tacoma, Washington welds the five fabric layers simultaneously. The process is time consuming, requiring up to ten minutes for the machine to complete the discrete welds. Current prototype pads are being made with a prototype welder, but the company has a larger capacity machine in development. Somewhat surprisingly in this day of Asian-produced goods, the production pads will be made in Seattle.
The technology has taken over five years of development. They were initially looking to build a lightweight pad using conventional high loft insulation. This evolved into attempts to achieve semi-self inflation by orienting the matrix vertically. Eventually a horizontal matrix was decided upon to reduce the number of welds needed and improve warmth by reducing the vertical size of the "chimneys" inside each cell.
Materials consist of a 30 denier high tenacity ripstop nylon shell, nylon non-woven inner layers, and a central aluminized, urethane-coated, reflective layer. The layer sandwich is claimed to offer an R-value of R-2.5 at 1.85 inches of inflation. (As with all inflatable pads, the R-value depends on the inflation thickness – more air equals more insulation.)
The technology and design of the pad appear impressive, but as with any potentially revolutionary product, we’ll have to wait and see if production versions live up to the initial promise. A full review of the NeoAir is in the works at BackpackingLight.com. The pad will be available April 2009 in four sizes.
Features of the Small Version:
- Dimensions: 20 x 47 in (51 x 119 cm)
- Claimed Weight: 9 oz (260 g)
- MSRP: US$119.95
What About Conventional Therm-a-Rests?
If the price or new technology of the NeoAir frightens you off, Cascade Designs has completely revamped the rest of the Therm-a-Rest pad line. The existing Prolite 4 series of pads has been updated to increase warmth by a claimed 20% with no additional weight penalty by utilizing a "cross die-cut" foam configuration. Most self-inflating pads punch vertical holes through the foam to reduce weight and stuff size. These holes can create miniature chimneys for convective air currents.
The slanted die-cut foam technology in the new "Prolite Plus" pad is claimed to act as a barrier, slowing down the convective transfer of heat within the cell to the sleeping surface. The claimed weight remains unchanged at one and a half pounds for a regular seventy-two-inch mattress. Prolite Plus pads will be available in three unisex sizes with a claimed R-value of R-3.8, as well as one women’s version rated at R-4.5. MSRP’s range from US$79.95 to US$199.95 for the various sizes. Lengths range from forty-seven to seventy-seven inches. Available March 2009. If the field performance matches the claimed R-values, these pads should all be amply warm as sole pads for winter use.
The three-season small size Prolite Pad with a claimed weight of eleven ounces. Note the aggressively rounded edges and tapered shape. An even lighter extra-small size will also be available.
For thee-season use, Therm-a-Rest has streamlined the shape of their existing Prolite 3 pads and renamed them, simply, "Prolite." The new pads are tapered slightly more aggressively and feature rounder tops and bottoms. These changes reduce the amount of material used for a given sized pad and result in weight reduction – always a plus for lightweight hikers. The new Prolite pads will be offered in three unisex sizes, plus a women’s size. The smallest and lightest pad in this series is the torso-sized extra-small version, measuring twenty by thirty-six inches, and claiming an eight ounce weight. This makes it one of the lightest self-inflating pads commercially available. MSRP’s range from US$59.95 to US$119.95, depending on size. Available January 2009.
No Oyl Shortage Here
Pacific Outdoor Equipment is going green(er?) this year with the introduction of their Peak Oyl family of pads. The new pads incorporate foam made from palm oil and shells made from recycled PET fabric. The new foam is a polyurethane blend made from 40% palm oil rather than petroleum-based oil. The shell is at least partially made from recycled beverage containers. The first pads in this series are the Peak Oyl Lite and Peak Oyl Aero Mountain, replacing their current AO Lite and AO Aero Mountain pads. Their strategy is to introduce the Peak Oyl materials into these higher end products this year and have it trickle into the rest of their product line in the future. According to company vice president Greg Garrigues, migrating to the new, allegedly more eco-friendly materials required no compromise in weight or performance. The Peak Oyl Lite will be available in five standard and women’s sizes ranging from forty-eight to seventy-eight inches long and thirteen to twenty-one ounces (claimed). MSRP’s from US$70 to US$95. The Peak Oyl Aero Mountain will come in similar sizes with claimed weights from 18 to 29.5 ounces. MSRPs from US$114 to US$139.
Want To Design Your Own Sleeping Pad?
Pacific Outdoor Equipment is starting a new program next year called Über Concepts. They plan to release up to ten design iterations of a new pad throughout the year based on customer feedback. The idea is to produce small batches of pads each month and repeatedly revise the design with a very fast development cycle. Customers will make suggestions for improvements with each version, and the product will evolve throughout the year. Want a four-ounce twenty-four by twelve inch "shoulder blade" pad or extra cushioning for the small of your back? Join the program and become a pad designer.