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Mountain Hardwear AC 2 Review

While not versatile, this weight-focused tent is strong and perfect for lightweight alpine missions
mountain hardwear ac 2 4 season tent review
Credit: Mountain Hardwear
Price:  $750 List
Manufacturer:   Mountain Hardwear
By Ian Nicholson ⋅ Review Editor  ⋅  Nov 11, 2022
71
OVERALL
SCORE


RANKED
#10 of 17
  • Weight - 27% 9.0
  • Weather/Storm Resistance - 25% 7.0
  • Livability - 18% 5.0
  • Ease of Set-up - 10% 9.0
  • Durability - 10% 6.0
  • Versatility - 10% 5.0

Our Verdict

The updated Mountain Hardwear AC 2 is a bivy tent aimed to provide a maximum level of storm protection with a minimal amount of weight. Among the lighter and more compact 4-season models we tested, it holds its own in the wind and driving snow. However, its low weight does come with tight internal dimensions. Its 25 square feet are nearly the smallest in our review. Its fabric offers superb weather protection but isn't the best for handling condensation. It's perfect for weight-focused trips in the mountains but not nearly as versatile as some of the other models in our review.
REASONS TO BUY
Lightweight
Durable
Easy to pitch
Small foot print
Stormworthy
Small packed volume
REASONS TO AVOID
Little internal space
Poor breathability
Poor ventilation

Compare to Similar Products

 
Awards  Editors' Choice Award Editors' Choice Award Top Pick Award Best Buy Award 
Price $750 List$900 List
$799.95 at Backcountry
$660 List$800 List
Check Price at REI
$449 List
$449.00 at REI
Overall Score Sort Icon
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Pros Lightweight, durable, easy to pitch, small foot print, stormworthy, small packed volumeBomber, great durability, compact footprint, lighter than average weight, fantastic balance of strength, weight, and livability, ample guy pointsVersatile, lightweight, double wall design works far better in rain than single wall models, handles condensation well, big vestibules, easy to pitchIncluded removable hooped vestibule, above average breathability among single wall tents, excellent ventilation, good headroom, compressible, robustLightweight for a double wall tent, inexpensive, versatile, easy set-up, interior fabric handles condensation well, and longer-than-average dimensions make this a better option for taller people
Cons Little internal space, poor breathability, poor ventilationPoor ventilation, slightly tricky setup, insufficient guy lines includedIsn't as strong as other 4-season models, offers a good but not excellent packed sizeGuylines are light duty, not quite as storm worthy as other models, fabric is less resistant to tearing and long term exposure to UVTiny vestibule, one of the weakest 3(.5)-pole designs in our review, only one door
Bottom Line While not versatile, this weight-focused tent is strong and perfect for lightweight alpine missionsAll-around uses are this model's forte, but it's still robust enough for when the weather turns gnarThe ski and summer mountaineering focused design perfect for almost any trip you can dream upA versatile single wall tent that works well for a greater range of conditions than most other 2-pole bivy-tent modelsA solid 4-season shelter at an excellent price. Great for summertime mountaineering or winter camping near treeline
Rating Categories Mountain Hardwear AC 2 Black Diamond Eldorado MSR Access 2 The North Face Assa... REI Arete ASL 2
Weight (27%)
9.0
7.0
8.0
9.0
6.0
Weather/Storm Resistance (25%)
7.0
9.0
7.0
6.0
7.0
Livability (18%)
5.0
7.0
7.0
7.0
7.0
Ease of Set-up (10%)
9.0
7.0
9.0
7.0
9.0
Durability (10%)
6.0
10.0
7.0
7.0
7.0
Versatility (10%)
5.0
7.0
9.0
6.0
8.0
Specs Mountain Hardwear AC 2 Black Diamond Eldorado MSR Access 2 The North Face Assa... REI Arete ASL 2
Minimum Weight (only tent, fly & poles) 3.5 lbs 4.5 lbs 3.80 lbs 3.5 lbs (no vestibule) 5.75 lbs
Floor Dimensions 81 x 45 in 87" x 51 in 84 x 50 in 82 48 in 88 x 57/60/44 in
Peak Height 45 in 43 in 42 in 42 in 43 in
Measured Weight, with tent, stakes, guylines, pole bag 4 lbs 4.9 lbs 4.1 lbs 5.44 lbs 6.25 lbs
Type Single Wall Single Wall Double Wall Single Wall Double Wall
Packed Size 6 x 11.5 in 7" x 19 in 18 x 6 in 7 x 22 in 6 x 6 x 20 in
Floor Area 25.3 sq ft 31 sq ft 29 sq ft 27.3 sq ft 32.9 sq ft
Vestibule Area N/A 9 sq ft (optional) 17.5 sq ft 10 sq ft 8.7 sq ft
Number of Doors 1 1 2 1 1
Number of Poles 2 2 2 4 4
Pole Diameter 9 mm 8 mm 9.3 mm 9.3 mm
Number of Pockets Side: 0 Ceiling: 0 Side: 4 Ceiling: 0 Side: 2 Ceiling: 0 Side: 2 Ceiling: 0 Side: 2 Ceiling: 2
Pole Material DAC Featherlite NSL Easton Aluminum 7075-E9 Easton Syclone DAC Featherlite NSL Aluminum
Rainfly Fabric main body: 50-denier ripstop nylon, floor: 30-denier ripstop nylon 3 layer ToddTex 20D nylon ripstop FUTERLIGHT Nylon ripstop
Floor Fabric 30D ripstop nylon Unknown 30D nylon ripstop 40D ripstop nylon w/3,000mm PUR/silicone coating Nylon taffeta

Our Analysis and Test Results

The Mountain Hardwear AC 2 puts as much weather protection as possible into a lightweight and compact design. One of the lighter and more compressible models we tested, the AC 2, can hold its own in inclement weather, but its light weight does come at a cost, and that is versatile and comfortable. The AC 2 is nearly the absolute smallest model we tested when it comes to internal floor space, and it handles condensation among the poorest. We found it perfect for summertime mountaineering adventures or carry-over alpine routes where you are primarily bringing a tent for warmth and shelter and aren't doing much in the tent outside of sleeping. It isn't a great option if you think you will have to spend a fair amount of time in it or want to use it for more-three seasons of applications.

Performance Comparison



mountain hardwear ac 2 4 season tent review - a bomber bivy tent the mountain hardwear ac 2 is ultra easy to set...
A bomber bivy tent the Mountain Hardwear AC 2 is ultra easy to set up and offers a very good blend of strength and weight to make it an ideal shelter for alpine climbing on routes where weight and compressed volume are among the most important factors. .
Credit: Ian Nicholson

Weather Resistance


This tent is made to perform well in poor weather and performed slightly above average among single-wall models. It is constructed with a thicker-than-average 50D ripstop nylon fabric and features robust pole sleeves (versus clips) that help distribute the load from wind and snow along the entire pole, helping it to hold up to the elements. The ample guy points and included guylines help it to withstand a beating when camped in exposed areas. It is also designed with a slightly narrower profile than most that, when pitched with the door-end, is leeward and held up to stronger winds quite effectively. We also found this narrow profile greatly assisted in minimizing how much snow stays on the tent itself during snow storms, instead allowing most of the fallen snow to "sluff" off of the tent.

mountain hardwear ac 2 4 season tent review - the ac2 was the most "water proof" among the sub-4-pound 2-pole bivy...
The AC2 was the most "water proof" among the sub-4-pound 2-pole bivy tents and due to superior ventilation features a number of "superlight" tents was among the easier to stay dry in.
Credit: Ian Nicholson

Livability


The AC 2 has many noble qualities, but comfort is not the first among them. At a scant 81 inches long, it is one of the shortest tents in the category, and its 45-inch width is also one of the narrowest. Its 25.3 square feet of interior space is also the smallest in our review, so it almost goes without saying that this model is designed as a "bivy-tent"; enough space for two full-length pads to sit side-by-side and two people but without any extra.

mountain hardwear ac 2 4 season tent review - the ac 2 is focused on being as light and compact as possible while...
The AC 2 is focused on being as light and compact as possible while still offering respectable strength and weather protection. As such it isn't the most comfortable to hang out but it's great for trips where weight is important and you don't plan on spending a lot of time in your shelter.
Credit: Ian Nicholson

This model features a 45" peak height which is very similar to most other 2-pole models and is just enough for most people to sit up in but two people "getting ready" inside the tent feels tight. As a "bivy tent," it is comfortable enough for summer-time mountaineering objectives or carry-over alpine routes but wouldn't be a model we'd recommend if you knew you were likely to log some time with another person in. While this tent is spacious for one person, so are all the other tents in our review.

mountain hardwear ac 2 4 season tent review - with just enough room for two full-sized pads the ac 2 still...
With just enough room for two full-sized pads the AC 2 still squarely fits into the "bivy tent" category.
Credit: Ian Nicholson

Breathability

One word of caution here is that this model is heavily sealed, so it's important to stay mindful of ventilation to minimize condensation. Among single-wall tents, this model does not breathe as well as most and does not pass moisture through its fabric as effectively as the Black Diamond Eldorado.

mountain hardwear ac 2 4 season tent review - this model was easier to manage condensation than the msr advance...
This model was easier to manage condensation than the MSR Advance Pro 2, the BD Firstlight or Highlight but not as well as the North Face Assualt (due to all of its ventilation options) or the Black Diamond Eldorado (because of superior breathability in its Tod-tex fabric.
Credit: Ian Nicholson

It offered similar breathability to The North Face Assault 2 FUTURELIGHT but Assualt offered far better ventilation options, and managing moisture in that tent was far easier than with the AC 2. This model does offer two top vents, but if we were forced to zip the main door all the way we would certainly notice a build-up in condensation. Lastly, it should be noted that while there is no built-in or included vestibule, vestibule attachment can be purchased separately.

mountain hardwear ac 2 4 season tent review - showing the small vent on the back of the ac 2 that helps transfer...
Showing the small vent on the back of the AC 2 that helps transfer air and moisture and can be left open even in the rain.
Credit: Ian Nicholson

Ease of Setup


This tent is surprisingly easy to set up, particularly if it isn't too stormy out (AKA too windy). This model features two full-length pole sleeves that are only open at one end on the front side of the tent. This means to pitch the tent, you simply have to thread the pole into the start of the sleeve and just push until the pole runs into the end (and closed) side of the pole sleeve.

mountain hardwear ac 2 4 season tent review - the ac 2 was among the absolute easier tents to set up. here karen...
The AC 2 was among the absolute easier tents to set up. Here Karen Bockel pitches an AC 2 in Boston Basin.
Credit: Ian Nicholson

Like most models that feature pole sleeves, this model does take more care when pitching in windier conditions. This is because the tent can act as a "sail" when only one pole is inserted, and care should be taken not to lose the tent and to support the single pole as it is quite vulnerable at this point during pitching.

mountain hardwear ac 2 4 season tent review - to pitch the ac 2; simply push the poles into the external sleeves...
To pitch the AC 2; simply push the poles into the external sleeves. The sleeves are closed off and fixed at one end. This means you just push the pole in until you can't anymore and then clip the open end into a traditional groment-type closure.
Credit: Ian Nicholson

Even with a little more care is required when pitching during windier conditions, the fast and easy nature of pitching this tent with its continuous pole sleeves that only require fixing at one end and the incredible strength the pole sleeves provide, we felt like pole sleeves (versus clips) was a good decision on a tent of this weight and overall this model was among the easiest and fastest single wall models to pitch being equal to The North Face Assualt and far easier than the Black Diamond Eldorado.

mountain hardwear ac 2 4 season tent review - the external pole sleeves are sealed at one end making for an easy...
The external pole sleeves are sealed at one end making for an easy pitch. The open side of the pole sleeves uses a traditional grommet style attachment which was well tensioned and easy to use.
Credit: Ian Nicholson

Weight/Packed side


With a 3lbs 8 ounce minimum weight (no guylines or stakes), a 3lbs 12 ounce weight (guylines and a few stakes), and a 4 lbs for everything (All including stakes, guylines, stuff sack), this tent is quite respectable but and is similar in weight to the North Face Assualt (compared without the Assualt's included, removable vestibule) or MSRS Access 2 but lighter than the Black Diamond Eldorado(but smaller and less breathable).

The AC 2 is also similar in packed volume to most other 2-pole bivy style tents save for the MSR Advanced Pro (no mesh door), Black Diamond Highlite, and Frist light which both use a high water resistant but not waterproof fabric, which is a little lighter and more compactable. The AC 2 is notably more compact (25% smaller) than the Mountain Hardwear Outpost II, the Black Diamond Eldorado and similar in size to the MSR Access 2.

mountain hardwear ac 2 4 season tent review - looking out the lone door on the mountain hardwear ac 2.
Looking out the lone door on the Mountain Hardwear AC 2.
Credit: Ian Nicholson

Versatility


This model is not particularly versatile. It is great for summertime mountaineering routes where weight is paramount, and the goal of the tent is to keep you out of the elements for the evening, and you don't anticipate any "extra" time in the tent. That makes if perfect for many summertime mountaineering adventures in the lower 48 and Southern Canada. It is also a great option for an on-route shelter for carry-over alpine routes. While it is certainly light and strong enough for multiday ski tours, its so-so ability to handle condensation means it works but isn't our first choice unless your adventure is in a drier climate (not the Chugach, Western BC, Washington Cascades, etc.).

mountain hardwear ac 2 4 season tent review - showing the upper vent and the top of the door on the ac 2. there...
Showing the upper vent and the top of the door on the AC 2. There are two vents that can be left open on this model even in the rain. There is one vent located on each side of the tent (front and back).
Credit: Ian Nicholson

mountain hardwear ac 2 4 season tent review - this model is great for its designed to do, be as light and compact...
This model is great for its designed to do, be as light and compact as it can while providing just enough shelter to help its occupants through a good night's sleep in the alpine enviorment and survive the elements should the weather take a turn for the worst. With that said it is not very versatile and a poor option for extended or frequent three-season conditions or frequent, damp, rainy trips,
Credit: Ian Nicholson

Should You Buy The Mountain Hardwear AC 2


This tent is perfect for those who want one of the lightest and most compact 4-season shelters on the market while still offering a very weather-resistant fabric and built-in bug netting. While not the most versatile model in our review, the AC 2 is amongst the lightest, is completely waterproof, and offers a full-sized mesh door. While there are a handful of lighter models, all lighter-weight models sacrifice something when it comes to liveability or storm worthiness. Our review team found this model perfect for summertime alpine climbing or technical carry-over style routes where the AC 2 proved small enough to be pitched where other options don't have a hope of fitting. While perfect for weight-focused alpine adventures, this isn't a model we'd want to take on most three-season backpacking due to its poor performance in more humid environments and overall "cramped" interior space. If you want a versatile 4-season tent, this isn't it. If you want a weight-focused model that offers solid strength and storm worthiness, then this is certainly a good one to consider whether you are summer alpine climbing, sleeping on big routes in the greater ranges, or on a multiday ski tour. If you want a fairly light 4-season tent but want something a little more versatile (AKA can be used in 3-season conditions) we'd recommend checking out the MSR Access 2, MSR Remote 2 or Mountain Hardwear Outpost 2.

mountain hardwear ac 2 4 season tent review - one of our favorite bivy-style tents for alpine climbing. while a...
One of our favorite bivy-style tents for alpine climbing. While a 7-9 ounces heavier than the lightest of models it provides a ton more weather protection for what is a pretty minimal amount of extra weight.
Credit: Ian Nicholson

What other 4-season tent should you should consider besides the Mountain Hardwear AC 2


If you want a 4-season bivy tent as light as they come, it should be noted that both the Black Diamond Firstlight and the MSR Advance Pro 2 are both lighter weight and more compact. However, each of these models has a major disadvantage, the Firstlight is not completely waterproof, and the Advance Pro offers no bug netting and manages very poorly. If you like the AC 2 but wished it was just a little bit more versatile, we'd recommend looking at The North Face Assualt FUTURELIGHT 2, which offers more ventilation, the Black Diamond Eldorado with its Tod-Tex fabric which handles moisture far better, or the double-walled Mountain Hardwear Outpost 2 or the MSR Access 2. All of these models are heavier but offer a more "livable design" and are more versatile.

mountain hardwear ac 2 4 season tent review - while not a do-anything-go-anywhere tent this superlight-weight...
While not a do-anything-go-anywhere tent this superlight-weight shelter is perfect for mountaineers and alpine climbers who are frequently pickier about the weather for their trip and often prioritize weight and packed size more than comfort and livability.
Credit: Ian Nicholson

Ian Nicholson
 
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