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The North Face Furnace 20 Review

All of the drawbacks of down with few of the benefits.
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Price:  $180 List | $178.95 at Backcountry
Compare prices at 2 resellers
Pros:  Anti-snag zipper sleeve, great minimalist stash pocket, affordable
Cons:  Heavy, bulky, no storage sack included, narrow-ish foot box
Manufacturer:   The North Face
By Jack Cramer ⋅ Review Editor  ⋅  May 19, 2019
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50
OVERALL
SCORE


RANKED
#7 of 10
  • Warmth - 20% 7
  • Weight - 20% 2
  • Comfort - 20% 6
  • Packed Size - 15% 4
  • Versatility - 15% 6
  • Features & Design - 10% 5

Our Verdict

The Furnace is an impressively affordable down sleeping bag. This down insulation, however, doesn't seem to provide the weight and packed size benefits that we're used to seeing. We were surprised to discover that it's just as heavy and bulky as several comparable synthetic models. So even though we love this bag's anti-snag zipper and minimalist stash pocket, there are several other budget sleeping bags that our testers prefer at the same price point. The Kelty Cosmic is a lighter, cheaper, and more packable down option, while the Nemo Kyan offers similar advantages with synthetic insulation.


Compare to Similar Products

 
Awards  Best Buy Award   Best Buy Award 
Price $178.95 at Backcountry
Compare at 2 sellers
$199.95 at REI
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$159.95 at Backcountry
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$169.95 at Backcountry
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$159.95 at REI
Compare at 3 sellers
Overall Score Sort Icon
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Pros Anti-snag zipper sleeve, great minimalist stash pocket, affordableAwesome warmth-to-weight ratio for the price, very compressible, tons of venting options, nice compression sack includedThick synthetic insulation, well-balanced performance, easy to use zipper, included stuff sackCheap, anti-snag zipper, sturdy materials, versatile synthetic insulationInexpensive, burly, decent warmth, roomy fit
Cons Heavy, bulky, no storage sack included, narrow-ish foot boxNot as warm as its temp rating, no draft collar, uncertain durabilityBulkier than expected, mediocre warmth-to-weight ratioModerate warmth-to-weight ratio, doesn't compress well, limited extra featuresHeavier than average, bulky, no storage sack, no compression sack
Bottom Line All of the drawbacks of down with few of the benefits.An exceptional deal for a lightweight bag that excels in wet conditions.A simple but effective synthetic mummy bag.An affordable workhorse with solid all-around performance.A legit backpacking sleeping bag that won't cost you an arm and a leg.
Rating Categories The North Face Furnace 20 NEMO Kyan 35 The North Face Cat's Meow 20 Mountain Hardwear Lamina 30 Kelty Cosmic 20
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Specs The North Face... NEMO Kyan 35 The North Face... Mountain Hardwear... Kelty Cosmic 20
Measured Weight (size long, in lbs) 2.94 1.89 2.39 2.28 2.63
Temperature rating (F) 20 35 20 30 20
EN lower limit (rating for men)/ EN Comfort Rating (rating for women) 14 / 26 35 / 46 22 / 33 27 (lower) 19 (lower)
Manufacturer claimed weight of size Regular (lbs) 2.63 1.69 2.25 2.17 2.41
Compression/Stuff Sack Weight (oz) 2.0 2.4 4.0 3.7 0.8
Compressed Volume (L) 10.3 6.6 11.4 8.6 8.7
Fill 600 ProDown Synthetic - Primaloft Silver Synthetic - Heatseeker Guide Synthetic - Thermal.Q 600FP Down (83%) / Polyester (17%)
Hydrophobic down? Yes N/A N/A N/A Yes
Fill Weight (Reg oz) 27 12 26 Unknown 18.2
Shell material Polyester Ripstop nylon (20D) 20D Nylon Ripstop Ripstop nylon (30D) 20D Nylon taffeta
Neck Baffle No No No No Yes
Small organization Pocket Yes No Yes No Yes
Zipper 3/4-Length Side Full-length / Side Full-Length Side Full-lengh / Side 3/4-Length Side
Shoulder Girth (Reg) 63 in 62 Unknown 60 64 in
Hip Girth (Reg) 59 in 57 Unknown 58 60 in
Foot Girth (Reg) 46 Unknown
Stuff or compression sack included? Stuff Compression Compression Compression Stuff
Storage sack included? No Yes Yes Yes No
Water resistant shell? No DWR No DWR No
Total Weight (Long size, in Pounds) 47.0 30.2 38.2 36.4 42.0
Manufacturer claimed weight (Long, oz) 47 30 39 Not listed 42.7

Our Analysis and Test Results

The North Face has an extensive selection of sleeping bags. After recently testing their Cat's Meow, Hyper Cat, and Furnace sleeping bags, however, we're not sure how the Furnace fits into the mix. Read on to find out why we think it's the odd one out.

Performance Comparison


The author was nervous he'd selected the down filled Furnace for this tentless overnight. Fortunately  the dark clouds passed without precipitation.
The author was nervous he'd selected the down filled Furnace for this tentless overnight. Fortunately, the dark clouds passed without precipitation.

Warmth


The Furnace is filled with 14 ounces of 600 fill power ProDown. With this insulation, it receives an impressive 14°F lower limit rating on the industry-standard EN test. Our testers acknowledge that it's one of the warmest 3-season budget sleeping bags out there. However, we don't think its quite as warm as its rating compared to some overachieving premium bags.

The Furnace is plenty warm for a 3-season budget bag  but didn't quite live up to its 14F limit rating in our tests.
The Furnace is plenty warm for a 3-season budget bag, but didn't quite live up to its 14F limit rating in our tests.

The Marmot Phase 20 and Rab Mythic 400, for example, are both filled with 14.1 ounces of much higher-quality 850+ fill power down, but receive worse EN temp ratings (19F and 21F, respectively). The Furnace is still plenty warm for most 3-season uses — but don't expect to stay toasty warm at its 14F EN rating. Its 20F manufacturer rating seems more reasonable.

Weight


Ordinarily down insulation is used to minimize weight. The down-filled Furnace, however, weighs 8 ounces more than its synthetic and comparably warm cousin, the Cat's Meow. The Furnace is also noticeably heavier than other budget down bags like the Kelty Cosmic 20 and Klymit KSB 35. It's thus not a great bag for the weight conscious shopper.

Comfort


This model is a fairly spacious mummy bag. Its 63-inch shoulder girth is among the widest in the budget sleeping bag category. The lining fabric, however, isn't as soft as the polyester taffeta in the REI Trail Pod 30 and Big Agnes Husted 20. Most sleepers will still find the Furnace to be plenty comfortable, but people that sleep on their side or stomach may prefer a bag with a roomier foot box for stretching their legs.

The Furnace comes with a single drawstring stuff sack. This sack is loose enough that it doesn't compress the bag fully  and tight enough that you wouldn't want to store the bag in it long-term.
The Furnace comes with a single drawstring stuff sack. This sack is loose enough that it doesn't compress the bag fully, and tight enough that you wouldn't want to store the bag in it long-term.

Packed Size


Another reason to use down insulation is to minimize packed size. In this area, The North Face succeeds — the down Furnace compresses 1 liter smaller than the synthetic Cat's Meow in our tests with a third-party compression sack. The Cat's Meow, however, comes with its own compression sack, while the Furnace includes only a simple drawstring stuff sack. Thus, to enjoy its superior packed size, you will need to buy an after-market compression sack.

Versatility


Although down often weighs less and packs smaller than synthetic insulation, it clumps and loses its ability to insulate if it gets wet. Like a lot of modern sleeping bags, the Furnace contains down that's chemically treated to be water resistant. If exposed to real moisture, however, this treated down will still clump. A synthetic bag like the Nemo Kyan or Cat's Meow is thus better for wet conditions.

The Furnace still provides decent versatility though. Its ¾-length zipper is effective at venting excess heat on warmer nights, while its significant insulation extends its useful temperature range lower than many other budget sleeping bags.

A standard zipper like that on The North Face Cat's Meow (top) is prone to snagging on the adjacent lining fabric. The Furnace  however  uses a groove of firmer black fabric (bottom) to keep the silky lining fabric away from the teeth.
A standard zipper like that on The North Face Cat's Meow (top) is prone to snagging on the adjacent lining fabric. The Furnace, however, uses a groove of firmer black fabric (bottom) to keep the silky lining fabric away from the teeth.

Features and Design


There are a couple of subtle features on this bag that we like. Although the zipper doesn't feature an anti-snag slide, the partial sleeve of stiff fabric that's sewn next to it is effective at preventing snags. The Furnace also has a convenient stash pocket for storing a phone or headlamp. It happens to be our favorite stash pocket because it's on the inside of the bag where your batteries will stay warm, and its zipperless design is ultralight.

The stash pocket on the Furnace is one of our favorites because its zipperless design is lightweight and it's located inside the bag where your phone batteries will stay warm.
The stash pocket on the Furnace is one of our favorites because its zipperless design is lightweight and it's located inside the bag where your phone batteries will stay warm.

Best Applications


This bag is a capable all-arounder. Its warmer temperature rating is ideal for "cold sleepers" and spring and fall overnights. The durable shell fabric should also hold up to continual abuse. Be certain, however, to keep its insulation dry, or it will lose its warmth advantage.

Value


The Furnace is one of the more affordable down bags out there. However, it's notably bulkier and heavier than the Kelty Cosmic, which lists for $10 less. Other similarly priced synthetic bags also provide similar warmth while weighing less and packing smaller. For these reasons, we don't consider the Furnace a particularly great value.

Saving money is always tempting  but in some cases  it's just not worth it. The Furnace  for example  is a low-priced down bag but doesn't perform as well as a cheaper synthetic bag from the same manufacturer.
Saving money is always tempting, but in some cases, it's just not worth it. The Furnace, for example, is a low-priced down bag but doesn't perform as well as a cheaper synthetic bag from the same manufacturer.

Conclusion


Sleeping bag makers generally use down insulation to minimize weight and packed size. The Furnace is filled with 600 fill power down, but it's not particularly light or packable. Its synthetic The North Face cousin, the Cat's Meow, offers comparable warmth while weighing 8 ounces less. The Cat's Meow's synthetic insulation also won't lose its ability to insulate if it gets wet. Still, if you can find the Furnace on sale, it could be worth considering. Otherwise, we prefer the Kelty Cosmic 20 for a budget down sleeping bag.


Jack Cramer