Outdoor Vitals Down UnderQuilt Review
Outdoor Vitals StormLoft Down UnderQuilt Review
In this Outdoor Vitals StormLoft Down UnderQuilt review, we share our experience using the 15°F version on hammock camping trips in the USA, including several weeks of backcountry testing in Colorado. It kept our tester impressively warm in temperatures from the low 30s into the mid-40s, although the suspension system took a little practice to dial in properly.
Outdoor Vitals built the StormLoft as a lightweight hammock underquilt using 800-fill-power down and a contoured shape that hangs beneath the hammock rather than being compressed underneath you. That basic concept works extremely well, and after using this quilt I understood why so many hammock campers eventually move away from sleeping pads.
This review is based on hands-on testing of the 15°F StormLoft rather than simply reading the specification sheet. It was used on various hammock camping trips and compared directly with the sleeping-pad system I had previously used.
Update: Outdoor Vitals still has the StormLoft underquilt listed, but the company now states that it will not be restocked. That makes this review especially useful if you already own one or find one remaining in stock or second-hand, but I would not treat it as a long-term current-model recommendation.
Outdoor Vitals StormLoft 15 Specifications
Temperature rating: 15°F version tested
Weight: 1 lb 7.5 oz for the 15°F Regular version
Fill: 800-fill-power StormLoft water-repellent down
Shell: Lightweight ripstop nylon with DWR treatment
Shape: Contoured hammock underquilt
Suggested use: Hammock camping and backpacking
The original specifications listed the Regular size as suitable for people around 6 feet tall, with a longer version available for taller campers. Our tester is 5’7″ and fitted well inside the quilt, although she felt the Regular version could become marginal for somebody close to the stated 6-foot limit depending on how they sleep.
Outdoor Vitals StormLoft UnderQuilt Highlights
- 800-fill-power down insulation
- Contoured shape for hammock use
- Adjustable suspension system
- Draft control at the ends
- Lightweight and highly packable
- DWR-treated outer fabric and down
Pros and Cons
- This quilt kept me toastie warm all night long — and that never happens!
- Very good warmth for the weight
- Adjustable while you’re already in the hammock
- Much more reliable underneath me than my old sleeping-pad setup
- Compresses down well for backpacking
- The suspension takes a few attempts to understand properly
- My first setup left drafts around my feet
- The Regular length felt shorter in use than I expected from the stated fit
- Outdoor Vitals says the model will not be restocked
StormLoft Suspension System
The suspension system was probably the least intuitive part of the StormLoft when I first used it. Once you understand how the shock cord and end cinches interact, though, it becomes much easier to pull the quilt snugly around the bottom of the hammock and make small adjustments without completely rebuilding the setup.
That adjustment matters because an underquilt works best when it sits close enough to the hammock to prevent cold air flowing through the gap, while still hanging freely enough that you don’t compress the down. Too loose and drafts move through underneath you; too tight and you squash the insulation you paid for.
How Does a Hammock Underquilt Work?
When you lie on top of a sleeping bag or quilt inside a hammock, your body compresses the insulation beneath you. Down and synthetic insulation work by trapping air, so once that loft is flattened, it provides far less warmth underneath your body.
An underquilt solves this by hanging outside the hammock where your body weight cannot compress it. The insulation remains lofted underneath you and creates a warm layer between the hammock fabric and the outside air.
The underquilt should sit close to the hammock, but it doesn’t need to be crushed tightly against it. A small enclosed air space is useful; what you want to avoid is a large drafty gap that allows cold outside air to continually flush through underneath you.
Why Use an Underquilt Instead of a Sleeping Pad?
I hammock-camped throughout my hike of the Appalachian Trail, but rather than using an underquilt, I used my sleeping pad to create a barrier between myself and the bottom of the hammock. For my purposes, that system worked fairly well as long as the sleeping pad stayed underneath me.
That was always the annoying part. Pads can slide, curl and move inside a hammock, especially when you turn over during the night. After testing the StormLoft 15, I started to understand why dedicated hammock campers are so enthusiastic about underquilts.
The underquilt simply stays underneath the hammock doing its job. I wasn’t waking up trying to wrestle a sleeping pad back underneath my hips, and the warmth felt much more evenly distributed.
Backcountry Testing
One of the questions I used to ask myself when packing for a hammock trip was whether I really wanted to risk hammock camping if temperatures were going to drop. Some previous hammock experiences had left me feeling more confident in the insulation of a tent, until I started using the StormLoft 15.
I tested this underquilt in Colorado’s backcountry over the course of a few weeks, with temperatures ranging from the low 30s into the mid-40s Fahrenheit. Paired with my Enlightened Equipment 0°F overquilt, I found myself sweating on more than one occasion.
That does not mean my test proves that every sleeper will be comfortable in the StormLoft at 15°F. Temperature ratings depend on your top insulation, clothing, shelter, wind, metabolism and how well the underquilt is adjusted, so I can only report what happened during my own testing conditions.
Adjusting the StormLoft in the Hammock
One feature I really liked was being able to move and adjust the quilt without completely undoing the suspension. That meant I could make small changes from inside the hammock if I noticed a cold area rather than getting out and starting again.
During my first night with the StormLoft, I struggled to cinch the ends tightly enough to stop drafts around my feet. After some additional rigging and experimenting, I finally got everything sitting properly and my toes stopped complaining.
Hammock camping is a little like skiing: you can learn the basics fairly quickly, but it takes much longer to get genuinely good at the setup. Every additional night with the StormLoft cut down my pitching time and made it easier to spot exactly where an adjustment was needed.
How Warm Is the Outdoor Vitals StormLoft 15?
In my own testing, it was extremely warm in temperatures from the low 30s to the mid-40s when paired with a 0°F Enlightened Equipment top quilt. On some nights, I was actually too warm rather than cold.
That’s encouraging for a product carrying a 15°F rating, but I would not translate that directly into a promise that everybody will be comfortable at 15°F. Underquilt temperature ratings are heavily affected by setup, wind exposure, the rest of your sleep system and how warm you personally sleep.
The biggest difference I noticed wasn’t just absolute warmth; it was consistency. Once the underquilt was adjusted correctly, there was no sleeping pad moving away from me halfway through the night and leaving one side of my body exposed to the cold hammock fabric.
Outdoor Vitals StormLoft UnderQuilt Weight
The 15°F Regular version was listed at 1 lb 7.5 oz, or 23.5 oz. For the level of insulation it provides, that remains a respectable weight for a full-length down hammock underquilt.
The StormLoft was also available in different temperature ratings and Regular or Long sizes, so weights varied across the range. The official current product page still lists 0°F, 15°F and 30°F versions with Regular and Long options.
How Does the Outdoor Vitals StormLoft Compare?
The original version of this review compared the StormLoft against the Hyke & Byke Antero and Warbonnet Yeti using exact prices. Those figures have aged badly, so I wouldn’t pretend a price comparison written years ago is still useful today.
The more useful comparison is in design. The StormLoft is a full-length, down-filled underquilt with a contoured shape and integrated adjustable suspension, while products such as the Warbonnet Yeti Underquilt take a different approach and remain in current production.
The StormLoft’s original appeal was that it combined premium down, relatively low weight and a price below many cottage-industry hammock quilts. That value proposition was one of the things I liked about it when I tested it, although current shoppers now need to consider availability because Outdoor Vitals says the underquilt will not be restocked.
What I Liked Most About the StormLoft
Warmth was the obvious highlight. I am not somebody who automatically sleeps warm, so having an underquilt that left me sweating on more than one cold Colorado night made an impression.
I also liked the packability and the fact that once I had learned the suspension system, I could make fine adjustments while already lying in the hammock. That is a much nicer experience than climbing out every time you notice a draft.
Most importantly, it changed my opinion of sleeping pads in hammocks. Pads still work and they can be useful if you also sleep on the ground, but for dedicated hammock camping I found the underquilt far more comfortable and dependable.
What I Didn’t Like
The learning curve was real. The suspension didn’t feel completely intuitive on the first night, and poor adjustment left enough of a gap around the foot end for cold air to get in.
I also questioned the stated fit of the Regular length. At 5’7″ I was comfortable, but based on my experience I would have wanted to test the fit carefully before recommending that exact size to somebody around six feet tall.
Neither of those issues ruined the product, but they are worth knowing about because a badly adjusted underquilt can feel dramatically colder than the same quilt when everything is set correctly.
Is the Outdoor Vitals StormLoft Still Available?
As of the latest update to this review, Outdoor Vitals still has the StormLoft underquilt on its website in 0°F, 15°F and 30°F versions. However, the official product page states that it will not be restocked.
That means remaining inventory may disappear and individual temperature or size combinations may already be unavailable. If you’re reading this review after stock has gone, the article is still useful for understanding the product second-hand, but I would compare current underquilts rather than hunting one down at any price.
Outdoor Vitals StormLoft UnderQuilt Review: Final Thoughts
I was genuinely impressed by the Outdoor Vitals StormLoft 15 during testing. It packed down small, provided far more dependable insulation beneath my hammock than my old sleeping-pad setup, and kept me extremely warm during several weeks of Colorado backcountry use.
The suspension system needed a little attention before I had it working perfectly, but every additional setup became quicker and easier. Once properly adjusted, the combination of warmth, low weight and comfort made it very difficult to imagine going back to fighting with a sliding sleeping pad.
Ultimately, I’d much rather sweat in my hammock than spend the night shivering, and the StormLoft certainly managed that. The only major issue for somebody reading this review today is availability: Outdoor Vitals has effectively reached the end of the road with this particular underquilt.
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