The world's most in-depth and scientific reviews of outdoor gear

REI Co-op Joule 21 Review

The Joule is a great lightweight and quality choice for any backpacking adventures.
  • 1
  • 2
  • 3
  • 4
  • 5
Price:  $299 List | $299.00 at REI
Pros:  Warm, high-quality materials, good price
Cons:  Uncomfortable fit, zipper fabric bulky and uncomfortable
Manufacturer:   REI
By Jessica Haist ⋅ Review Editor  ⋅  Oct 9, 2018
  • Share this article:
78
OVERALL
SCORE


RANKED
#7 of 15
  • Warmth - 25% 8
  • Weight - 25% 7
  • Comfort - 20% 8
  • Packed Size - 15% 8
  • Features - 15% 8

Our Verdict

The REI Co-op Joule 21 is a high scorer, providing ample warmth wrapped in a lightweight design. It is heavier than the Neutrino but also warmer and much less expensive. It kept us warm and cozy on cold, wet, and windy nights in the High Sierra, and its 700 fill-power down insulation provides a good night's sleep in the backcountry. We also appreciated its low weight-to-warmth ratio, and think the Joule is an excellent choice for any backpacking need at a great price.


Compare to Similar Products

 
This Product
REI Co-op Joule 21
Awards  Editors' Choice Award  Best Buy Award  
Price $299.00 at REI$414.00 at Feathered Friends$528.95 at Amazon
Compare at 3 sellers
$329.95 at Amazon$299.96 at Backcountry
Compare at 2 sellers
Overall Score Sort Icon
100
0
78
100
0
92
100
0
89
100
0
86
100
0
83
Star Rating
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
  • 1
  • 2
  • 3
  • 4
  • 5
Pros Warm, high-quality materials, good priceHigh-quality down, warm, lightweightHigh-quality down, warm and lofty, light, a top tier productComfortable, lightweight, excellent materials, not constrictingLightweight, compressible, comfortable
Cons Uncomfortable fit, zipper fabric bulky and uncomfortableSizing not for everyone, fabric is a bit noisyVery expensiveComforter sometimes does not stay tucked inExpensive, not particularly warm
Bottom Line The Joule is a great lightweight and quality choice for any backpacking adventures.This high-end bag will keep you warm and comfortable from Spring to Fall in all conditions.The Flame is a new, high-quality backpacking sleeping bag at a high price.A great, high-quality choice at a relatively low price for those looking for a lightweight bag that doesn't sacrifice comfort.This lightweight sleeping bag is a great choice for alpine climbing or fast and light adventures.
Rating Categories REI Co-op Joule 21 Egret UL 20 Sea to Summit Flame 15 Cloud 800 Rab Neutrino 400 - Women's
Warmth (25%)
10
0
8
10
0
10
10
0
9
10
0
7
10
0
7
Weight (25%)
10
0
7
10
0
10
10
0
9
10
0
10
10
0
10
Comfort (20%)
10
0
8
10
0
9
10
0
9
10
0
9
10
0
8
Packed Size (15%)
10
0
8
10
0
8
10
0
9
10
0
9
10
0
9
Features (15%)
10
0
8
10
0
8
10
0
8
10
0
8
10
0
7
Specs REI Co-op Joule 21 Egret UL 20 Sea to Summit... Cloud 800 Rab Neutrino 400 -...
EN Comfort Rating (F) 21 20 (not EN rated) 15 26 21
Fill Type Water Repellent Duck Down Goose down Duck Down PFC-Free DriDown Ethically sourced European Goose down
Total Weight (lb.) 2.19 lb 1.72 lb 1.95 lb 1.7 lb 1.7 lb
Total Weight (oz) 35 oz 27.5 oz 31.2 oz 27.4 oz 27.2 oz
Women specific features Increased room at hips, decreased room at shoulders, extra insulation in heat loss areas Extra fill in footbox and chest Women's specific fit - more insulation in key areas More insulation per square inch than men's version Women's specific fit
Fill Power 700 950+ 850+ 800 800
Fill Weight (oz) 18 oz 17.3 oz (medium) 22.9 oz 14.8 oz 14.1oz
Material Ripstop Nylon (20D) Pertex Endurance UL Ultralight 10D Nylon Shell 15d nylon risptop Pertex Quantum
Neck Baffle Yes Yes Yes No Yes
Pocket No No No No Yes
Sleeping Pad Sleeve No No No Yes No
Zipper Length 62" 62" 56" N/A 62"
Shoulder Girth 58 in 54 in 60 in 59 in 60 in
Hip Girth 58 in 56 in 58 in 58 in 56 in
Foot Girth 38 in 38 in 40 in 39 in 38 in
Stuff Sack included? Stuff sack and storage bag included Stuff sack and storage bag included Stuff sack and storage bag included Stuff sack and storage bag included Stuff sack and storage bag included

Our Analysis and Test Results

A high-quality bag that's warm and relatively light, the Joule is a pleasant surprise to our testers.

Performance Comparison


The Joule provides an excellent balance of all the metrics at a reasonable price  making it a great all-around for backpacking or car camping.
The Joule provides an excellent balance of all the metrics at a reasonable price, making it a great all-around for backpacking or car camping.

Warmth


The Joule is one of the warmest sleeping bags, beating out competitors rated at 15 degrees. We feel that its EN rating of 21°F is dead on, and indeed, it kept us warm down to that temperature. The bag feels cozy, and the 700 fill down is very lofty. The Joule's shell material protected our testers from the wind when they slept out under the stars on windy nights.

This bag is super warm keeping us cozy in freezing temperatures.
This bag is super warm keeping us cozy in freezing temperatures.

The bag's shell material has a waterproof coating. This detail was added peace of mind when we were in a torrential downpour in a floorless shelter. It kept us dry throughout the night despite a constant misting from water bouncing off of the ground and tarp. This bag could be a good option for someone who wants a down bag in a wet climate like the North Cascades.

Weight


The Joule 21 weighs in at 2.19 pounds, which is not super lightweight for a down sleeping bag but still suffices for any backpacking trip. As the years go by, more and more competitors are surpassing this product in this category, and it is easy to get a sub-two pound product for about the same price.

Comfortable and cozy for any outdoor camping trip.
Comfortable and cozy for any outdoor camping trip.

Comfort


Thankfully, REI has abandoned the woman's hour-glass shape and made the leg area larger. This change is an upgrade. The proportions were previously about as exaggerated as Barbie's. Now the bag is much more comfortable, and the dimensions are much more comfortable for sleep.

Great dimensions and a midweight design.
Great dimensions and a midweight design.

Packed Size


The stuff sack included with the Joule is not a compression sack but is made from lightweight materials. When we took it out in the backcountry, we used one of our own compression sacks instead, and it packs down quite small. This arrangement makes it a great choice for backpacking.

Features


REI has trimmed the fat in this department, and we are in favor of the work they have done. They have gotten rid of the stash pocket entirely and added a light colored liner fabric so you can find your missing sock without difficulty. The color hides dirt. The zipper works well, contrary to reports we read about this bag and so we are wondering what's with the super burly zipper lining fabric? We think it may be a reaction to complaints of zippers catching on this bag, but unfortunately, it adds weight and bulk, and our testers can feel it when they're sleeping; it bunches and creates a hard, uncomfortable lump.

A look at its burly zipper.
A look at its burly zipper.

Although the waterproof coating on this bag works well, it also adds extra weight. We appreciate the degree of mental comfort it gave us when using it in an exceptionally wet summer season in the Sierra. We watched water bead off the coating with relief more than once in our floorless shelter, but we wonder how long this coating will last without being re-treated.

A look at the collar that adds a little extra warmth and features.
A look at the collar that adds a little extra warmth and features.

Best Application


Overnight to week-long backpacking trips are what this bag does best. For truly long-distance thru-hiking, we would opt for an even more lightweight model. But for the majority of folks heading on backpacking trips, the Joule 21 is ideal.

Value


The Joule is a decent value for your money and we agree that it is worth it to invest in a quality down bag like this model. It retails at just around $300. If you're looking for something that is not quite as warm, but will save a pound of weighing we'd recommend spending an extra $30 and picking up the Sierra Designs Women's Cloud 800

Balancing all elements of what makes a great backpacking bag  the Joule provides great overall performance.
Balancing all elements of what makes a great backpacking bag, the Joule provides great overall performance.

Conclusion


The REI Co-op Joule 21 is warm and relatively lightweight. It is a great choice for your backpacking adventures.


Jessica Haist