The Therm-a-Rest Haven is part of a 2010 expansion of the Cascade Designs Sleep System, that was itself unveiled a couple of years ago. With designs that featured comfort ahead of low bulk and weight, the initial system targeted traditional campers. Presently the lone bag in the system’s new Fast & Light segment, the Haven is the first Therm-a-Rest bag for backpackers. Based on the specs, it seems to offer a light, compact, and affordable substitute for a typical 20 F (-7 C) down mummy bag. So, does it?
Design & Materials
Viewed from most angles, the Haven is a typical mummy bag, sans zipper. Flip the Haven over, however, and you’re greeted by an elastic-edged opening that to me looks like a plant’s stoma as viewed through a botany class microscope. This partial underside puts the Haven in the top-bag category, but the design seems unique (because it has a hood and doesn’t open flat, the Haven is not a quilt). The opening extends from about the shoulders to mid-thigh and, as noted, is stretchy. Rather than use a fabric sleeve to attach a pad or mattress, the Haven has two straps that attach to strap loops at each end of the opening. Each 1-inch strap has an adjustable snap buckle closure and can be removed in seconds if not needed.
The full hood has a simple drawstring perimeter closure with thin cord and a tiny cord lock. A small snap-closure pocket, just below the hood opening to the right, is big enough for a watch, small flashlight, etc., but not glasses. With no zipper, there’s no draft tube, nor is there a draft collar.
In sum, the Haven is a simple mummy bag with a big hole underneath.
Haven specs list 11.6 oz (332 g) of 700 cubic inch goose down fill for the size long, 20 denier nylon ripstop shell with DWR finish and 30 denier calendared nylon taffeta lining. Heavier than some makers’ 10 denier and 15 denier shells, the Haven shell is also less delicate. Therm-a-Rest calls the fabric’s gray color “pewter” but in reality it’s a lot darker than, well, pewter. Call it “ouzel” and know that with this bag you’ll be able to blend invisibly with basalt should you so choose. While perhaps lacking a positive colorful impact on campsite cheer, it’s hard to imagine a more dirt-concealing color.
The down chambers are fully baffled including side baffles, so there’s no shifting the down between top and bottom to respond to the temperature (not too relevant in a top bag). The elastic around the bottom opening stretches wide, affording considerable mid-bag expandability.
The Haven’s materials and design place it in the mid-grade down bag category, which the price basically reflects.
Fitting a Pad
Therm-a-Rest suggests using either a small tapered pad inside the Haven or a longer and/or rectangular pad outside, strapped underneath using the supplied straps. (They provided a size small ProLite to pair with the Haven for this test.)
The size large Haven tested weighs 25.2 ounces (714 g), including the 1.2-oz removable pad straps. Subtracting the manufacturer’s fill weight of 11.6 oz, the Haven shell sans straps is 12.4 ounces (352 g), or a bit more than half the bag’s weight. Some credit for the overall low weight can be chalked up to the lack of a zipper or draft tube, and the simple single-closure hood.
My length measurement essentially confirmed the 76-inch (193 cm) spec. It's not meaningful to measure the top two girth dimensions because with the Haven’s design, one simply stretches the opening until the dimensions match. But how much stretch is too much? Empty and unstretched, the bag closes up and the hip and shoulder girth dimensions are well under the 60-inch (152-cm) spec. Because of this property it’s not very revealing to compare the Haven’s width specs to those of a standard mummy bag - the stretchy opening makes it perhaps more comparable to expandable bags such as those from MontBell and Sierra Designs. The non-stretchy footbox measures about 38 inches (97 cm) compared to the 40-inch spec (but it’s difficult to guess where to take this measurement in the tapered foot area).
The Haven ships with a coated nylon stuff sack and a ventilated storage sack. The 10x8-inch, 0.8 oz (25x20 cm, 23 g) stuff sack is, to my liking, small for this bag, requiring dense packing to fit. While I’ve substituted a larger one, it is still possible to fit the Haven in the supplied sack for those who don’t mind cramming it in, and I’d guess the regular fits much more easily. I hasten to add that no matter the stuff sack, the Haven packs small and takes minimal backpack space. The very nice storage sack is well suited to the task.
Room and Comfort
Per the specs, the regular Haven fits those up to 5’10” and the large up to 6’4”. Girth is said to be the same for the two sizes. At 6’ and 175 pounds I find the large Haven roomy in all dimensions, including my feet, leaving ample space to wear insulated clothing from head to toe without excessive compression of the loft. By comparison, a slender mummy bag like my 20 F Western Mountaineering UltraLite (size long, 60/52/38) constricts insulated clothing, especially at the hips and legs. The UltraLite is also bulkier and larger than the Haven. My 20 F Feathered Friends Swift (64/58/40) matches the Haven for room, but is heavier and bulkier still.
The Haven’s simple hood is nicely contoured and warm. It closes from the side using the single cord and cord lock and requires two hands to adjust. The hood is reasonably comfortable and snug around my noggin on cold nights, although when I turn, it doesn’t always turn with me.
Fill and Temperature Rating
Therm-a-Rest has adopted the EN 13537 European rating system and for the Haven claims a “comfort” rating of 30 F (-1 C), a “comfort limit” rating of 20 F (-7 C) and an “extreme” rating of -10 F (-23 C). The standard roughly translates as follows: a standard woman (sleeping in a “relaxed” position) should be comfortable to 30, a standard man (sleeping eight hours in a curled position) should be comfortable to 20 and at 10 below, the “standard woman can remain for six hours without risk of death from hypothermia.” Frankly, if I ever find myself at -10 in this bag, I need to hire a trip planner or a life coach.
Ah yes, per EN 13537, “standard man” is 25 years old, 173 cm (~5'8”) tall and weighs 73 kg (161 lbs); “standard woman” is likewise 25, 160 cm (5'3”) tall weighing 60 kg (132 lbs).
Measuring the Haven’s loft is tricky. I found a rough average of four inches (10 cm) total loft where there are both a top and bottom layer and about two inches (5 cm) of loft atop the bottom opening, where there is but a single (top) layer. The handy BPL estimated temperature rating chart indicates the Haven falls between a 30 F and 20 F bag, which is consistent with my experience.
Down chambers are evenly filled, but not stuffed “fat” in the fashion of the best bags. I don’t note any insulation gaps examining the bag with strong back-lighting.
Therm-a-Rest recommends the pad be inside for best cold weather performance (presuming it’s a pad that fits) and outside the rest of the time.
At home I paired several pads with the Haven, including a full-length Big Agnes Insulated Air Core, a small NeoAir and the small ProLite self-inflator. I didn’t find any problems with these combinations. I typically use a short pad and pillow, and that’s what I field-tested. After trying the short ProLite and NeoAir, I settled on the NeoAir as my top choice-comfort is excellent, warmth is sufficient, and it’s my smallest, lightest pad. While the NeoAir inside the bag blocks drafts more effectively than strapped outside, the somewhat rubbery fabric isn’t terribly comfortable against my skin, so I prefer it outside. (By contrast the ProLite fabric is more comfortable against the skin and lends itself more to use inside the bag.) The Haven straps encircle the pad and do a decent job keeping it in place and centered, thereby reducing drafts through the bag opening.
Snug hood. No entry here!
The Haven design merits extra attention to entry and exit. In theory there are two ways-through the bottom and through the hood-but in practice the hood opening is so tight the bottom opening is much more practical (endomorphs and contortionists can perhaps ignore my observations). Naturally, bottom access is quick and easy when no pad is attached but trickier with the pad strapped on. My routine is to slide my legs in first, scoot down to the end, then pull the top over my head. Once inside I adjust the pad and ensure the bag opening is pulled snug. After some practice this has become second nature. Ease of entry is also affected by the shelter used - low, tight quarters like a tunnel-style tent make it more of a challenge.
Sleeping in the Haven
Especially because I’m a top-bag newbie, the Haven forced some habit adjustments. The biggest challenge is turning inside the bag to sleep on my side, rather than turning the bag with me as usual. If I turn the Haven sideways, the pad turns on its side too, and then I’m sleeping right on the ground. Turning sideways while leaving the bag in place sometimes has my face planted inside the hood.
The other challenge is ensuring the bottom opening remains covered by the pad, fending off drafts. This is mostly a finesse issue, because the Haven’s stretchy opening tends to stay somewhat closed - not completely - but normally enough to overlap the pad edges.
I slept in the Haven more than a dozen nights this season at altitudes between 7,000 and 10,000 feet (2,130-3,050 m). My shelters were one- and two-person Shires Tarptents and observed overnight temperatures ranged from the mid-50s down to the mid-20s, with the weather spanning mid-summer mild to cold and stormy with wind-driven snow and sleet. On the warmest nights I had to wriggle partway out of the hood to keep from overheating, and at these times would love some extra circumference in that opening. However, once my shoulders and arms are clear, there’s enough clearance around my chest.
On the coldest nights I wore long underwear top and bottoms and a knit cap and was sufficiently comfortable to conclude the Haven is a legitimate 25 F bag for my metabolism. The challenge is scrupulously keeping the bottom opening blocked by the pad, and here’s where having the pad inside might be better, as per Cascade Designs instructions, as opposed to my preference for strapping it outside. Whenever the opening is exposed, it’s announced by a blast of cold air, and as experience grew I got better at minimizing those moments. The key seems to be some combination of pad placement, pad strap tension and turning slowly rather than abruptly.
Fabrics & Wear Performance
Soak test and results.
The liner fabric is pleasingly soft and the ripstop shell is reasonably water-repellant. In a one-hour leak-through test using a cup of water, none made it through to the tray beneath. Although the shell fabric did become wet, it dried quickly once the water was poured off. In the field, the bag fended off dripping tent condensation, but my test didn’t include any hard rain or spindrift. While the liner proved downproof, the shell regularly leaks small feathers, represented by a flurry appearing in the tent each morning. Since calendaring is skipped in the shell-perhaps to enhance breathability-minor down loss appears to be a tradeoff here. It’s no goosey blizzard, so I’m not concerned about actual loss of loft, but I’m also not accustomed to seeing so much, so routinely.
The bag closet to the Haven we could find is the Rab Neutrino SL top bag (20.5 oz, $225-250). It’s significantly more slender at 55/41/32 (140/104/82 cm) and Rab does not provide a temperature rating. It does, however, spec desirable 800 ci down and uses bits of Primaloft in strategic spots. It also has a short zipper. Two quilts roughly within the Haven’s specs and price range are the GoLite UltraLite 3-Season Quilt (27 oz, $295) and the Jacks 'R' Better Sierra Sniveller (23 oz, $270). Neither has a hood and both spec better down. The Sierra Sniveller adds versatility, being wearable as a sort of parka.
Many more-expensive options exist in the 20 F down bag/quilt category. (Comparison against quilts may be a bit off-target, since the Haven is basically a hooded mummy bag with a hole in the bottom.)
Some 20 F high-end mummy bags:
- Western Mountaineering UltraLite. Long. 60/52/38. 31 oz/17 oz fill, 850 ci. $400
- Western Mountaineering Alpinlite. Long. 64/56/39. 33 oz/21 oz fill, 850 ci. $440
- Feathered Friends Swift. Long. 64/58/40. 36 oz/18 oz fill, 850 ci. $389
Some 20 F top bags/quilts:
- Nunatak Arc Alpinist hoodless quilt. Long. 55/45/38. 22-25 oz, depending on fabric/11 oz fill, 850 ci. $464
- Big Agnes Horse Thief hoodless top bag. Long. 72.5/69/44. 25 oz/12 oz fill, 800 ci. $320
- Big Agnes Tumble Mountain top bag. Long. 72.5/69/44. 51 oz/17 oz fill, 720 ci. $310
- Big Agnes Zirkel SL. Long top bag. 72.5/69/44. 34 oz/14 oz fill, 800 ci. $360
The Haven is attractively priced at $240 (regular) and $250 (large). The scant few top-bag/quilt competitors are spec’d with higher-loft down and generally thinner fabrics and most are much more expensive. Haven “penalties” for its lower price are greater weight and packed bulk - it weighs more than it would with higher loft down and a thinner shell, but then it wouldn’t hit this price point. Detangling the EN 13537 ratings is tricky, as it’s murky as to whether I’m reviewing a 30 F bag or a 20 F bag. Whatever the claims, a 20 F rating seems optimistic for my metabolism in the testing conditions encountered. At the least, the Haven is not as warm as my 20 F standard mummy bags, which routinely take me past that temperature milestone wearing only boxers and a T-shirt to bed. Such is the challenge of comparing similarly spec’d bags among different makers. The Haven is easily a 30 F bag and for me, is comfortable at 25 F, as noted above.
With its relatively tough shell and liner fabrics and lacking a zipper, there’s nothing dainty about the Haven - it demands no special care and presuming the shell and stitching hold up, it should provide the long life typical of down bags (decades, in my experience). I can find no wear or damage to the test bag despite treating it sans kid gloves (other than ditching the too-tight stuff sack). Being zipperless, the Haven is simpler and lighter but perhaps at the cost of less flexibility in warmer conditions and added difficulty entering and exiting.
So the Haven is roomy, warm, inexpensive, and lighter than competing full mummy bags. Therm-a-Rest’s take on the top bag is a conservative one with respect to how much of a traditional sleeping bag they’ve retained, but for those who find quilts and the competing top-bags expensive, fussy, or drafty, this design may work for you.
|Manufacturer||Cascade Designs, Therm-a-Rest|
|Style||Hooded zipperless top bag|
|What’s Included||Sleeping bag, stuff sack, storage bag|
|Fill||700 fill-power goose down, 10.6 oz (300 g) regular, 11.6 oz (330 g) long|
|Construction||5-inch (13-cm) baffles|
|Measured Loft||4 inches (10 cm) total, 2 inches (5 cm) top loft.|
|Manufacturer Claimed Temperature Rating EN 13537||“Comfort”: 30 F (-1 C)
“Comfort limit”: 20 F (-7 C)
“Extreme”: -10 F (-23 C)
|Stuffed Size||10 x 8 inches (25 x 20 cm)|
|Weight||Size large tested, measured weight: 25.2 oz (714 g)
Manufacturer specification: 24 oz (698 g) with 1.2 oz pad straps
|Sizes||Regular fits to 70 inches (178 cm) Long fits to 76 inches (193 cm)|
|Fabrics||Shell is 100% nylon ripstop, 20d, DWR finish
Liner is 100% nylon taffeta, 30d, calendared for down-proofing
|Features||Full single-drawstring hood, bottom opening, fully baffled, two removable pad straps with anchor loops|
|MSRP||Regular: US$240 Long: US$250|
Disclosure: The manufacturer provided this product to the author and/or Backpacking Light at no charge, and it is owned by the author/BPL. The author/Backpacking Light has no obligation to review this product to the manufacturer under the terms of this agreement.