The standard PHD Minim 400 sleeping bag is a zipperless mummy-style bag. It’s insulated with 800 fill-power down and rated at 23 F (-5 C). I tested this bag in size Short with their lightest shell fabric available.
A good way for some women to save weight on a sleeping bag is to purchase a size Short, which usually fits a person up to 5 feet 6 inches. However, only a few manufacturers of ultralight sleeping bags offer a size Short; PHD Mountain Software, a small company in Stalybridge UK, is one of them. Being a small company that manufacturers their bags themselves, PHD (which stands for Peter Hutchinson Designs) offers customers a variety of options (at extra cost).
I don’t need a sleeping bag with a lot of features. I just want to be WARM. So the basic zipperless hooded Minim 400 suits me just fine. To further reduce weight, I opted for their MX Microfiber shell fabric, which is their lightest (comes in black rather than red). I chose and tested a size Short (I’m 5 feet 2 inches) hooded and zipperless down sleeping bag rated at 23 F (-5 C) with a measured weight of just 22 ounces. I’m very pleased with the Minim 400’s weight and performance, as I report in this review.
The Minim 400 is a member of PHD’s ultralight series of sleeping bags. The basic bag is a hooded mummy-style, and it’s zipperless to save weight. If you desire a zipper, you can add a full-length zipper on either side of the bag for £25.
The beauty of working with a small company like PHD that makes each bag to order is that you can get exactly what you want. Rather than choose a specific model on their website, you can design your own sleeping bag from scratch. This gives you the opportunity to choose the length and girth (slender, standard, wide) you want, shell and lining fabrics, down quality and quantity, zipper length and position, and other options to satisfy your needs.
I chose to test the Minim 400 sleeping bag with minimal options. It’s a mummy-style bag with no zipper and insulated with 800 fill-power down. Rather than the standard microfiber shell fabric, I chose their lightest shell fabric, which is 0.88 oz/yd2 (30 g/m2) MX Microfiber. This fabric is calendared on both sides (more on the inside) to make it stronger and downproof, and it has a DWR finish. Since this is a minimalist down bag, there is not much else to describe.
I tested the Minim 400 while summer backpacking and car camping in the southern Rockies and southern Utah canyon country. I slept under the stars and inside single-wall and double-wall tents.
I live in southwest Colorado and backpack in the summertime in our local mountains, where nighttime temperatures often drop down into the 30s F(-1s C). In the fall I camp and hike in the southern Utah canyon country, where nighttime temperatures range from 35 to 50 F (2 to 10 C). To test the bag’s lower temperature limit, I slept on our back porch on a late fall night where the nighttime temperatures dropped to 19 F (-7 C).
The Minim 400 in the Standard size contains 400 grams of down. I measured my size Short bag’s double-layer loft to be an average of 5.25 inches/13.3 centimeters (2.6 in/6.6 cm of single-layer loft). From Backpacking Light’s table of estimated temperature ratings based on measured loft (read our Backpacking Light Position Statement on Sleeping Bag Temperature Ratings), 2.6 inches of single-layer loft translates to about a 10 F (-12 C) temperature rating, so the Minim 400’s 23 F (-5 C) rating appears to be very conservative. Please take the time to read the referenced article and note that sleeping bag warmth depends on a number of factors.
The Minim 400’s hood has seven panels and is operated by a braided drawcord and cordlock. It surrounds my head and places a breathing hole right at my nose and mouth.
Although many backpackers may prefer a zippered sleeping bag for the versatility it provides, I do not have any problems with sleeping in a bag without a zipper. I’m normally a cold sleeper, so I rarely have a problem with being too warm. Quite the contrary, I often wear my camp clothes inside my sleeping bag to provide extra warmth. The warmest night I spent in the Minim 400 was at Lake Powell in southern Utah, where it only got down to 50 F (10 C), and I slept comfortably with the top of the bag open and my body partly out of the bag. I have used a zipperless sleeping bag before (GoLite FeatherLite, 40 F/4 C), so I am familiar with the experience, and it doesn’t present me with any problems.
On my coldest night of testing (19 F/-7 C), I slept warm in the Minim 400 with baselayer and light insulated clothing until 4:00 a.m., when I noted the temperature to be 24 F (-4 C). I put on heavy insulated camp clothing I had stashed next to me. It took about thirty minutes to warm up the cold clothing, but then I was warm the rest of the night. Note that the Minim 400 has continuous baffles, so some of the down can be moved from the bottom of the bag to the topside to make the bag even warmer (this assumes you have a sleeping pad under the bag that provides adequate bottomside insulation).
I tested the bag’s water-repellency by placing a puddle of water on the shell and letting it stand for one hour (left). I found the bag’s shell fabric to be very water-resistant, but the seams easily transmit water. A large amount of water accumulated on a tray that I had placed inside the bag to catch the water (right). The down was wet in the area surrounding my test.
In my field testing, the ends of the bag came into contact with condensation inside a single wall tent. The bag’s shell easily shed that small amount of water, and water did not enter the bag through the seams. I did not test the bag in rainy conditions to see if the bag absorbed moisture from moist humid air. From my tests, I conclude that the bag’s DWR treatment on the shell and lining provides adequate water-repellency to keep moisture from entering the bag and wetting the down under normal conditions, but water will penetrate the seams. This performance is comparable to most other sleeping bags with a DWR treatment on the shell, and the Minim 400 has a DWR treatment on the lining as well.
The PHD Minim 400 comes with a durable stuff sack (0.9 ounce) that is properly sized to avoid overstuffing the bag.
The two ends of the hood drawcord are wrapped with a small piece of fabric and sewn together, which creates a bit of a lump (left side of picture). The drawcord is not anchored in its channel, so the lump is free to move out of the channel, and once out is quite difficult to get back in the channel (especially in the dark in the middle of the night).
I didn’t notice the drawcord problem before using the bag. As it got colder on the first night, I cinched the hood, the knot slipped out, and I couldn’t get it back in. To tighten the cord, I needed to pull just one of two cords through the cord lock. After becoming aware of this problem, I learned to keep the knot centered inside the channel by pulling both sides of the cord evenly through the cordlock. Another aspect of this problem was that when the lump came out of the channel, it pulled the unfinished hem out of one side of the opening of the channel as seen in the lower right quadrant of the photo. In my opinion, this design is not durable enough for the long term, and a redesign could readily solve the two problems (cord coming out and unfinished hem being exposed).
Overall, from my testing, I found the Minim 400’s temperature rating of 23 F (-5 C) to be realistic. Note that since I am a cold sleeper, I always need to wear extra insulation to stay warm at a bag’s temperature rating. This Minim 400 bag is adequately roomy to wear extra clothing inside to extend its warmth. The zipperless design is not a problem if you are a person who wants to save weight and rarely experience situations where it’s warmer than about 50 to 60 F (10 to 16 C) at night. For a short person, getting a size Short sleeping bag is an excellent way to save weight and stay warmer, because there is less bag to warm up.
The hooded zipperless PHD Minim 400 is in a class of its own. The best comparison is with other 20-30 F (-7 to -1 C) rated ultralight mummy style down sleeping bags that are available in a size Short. All of the bags have baffled construction, and all data are manufacturer specifications for a size Regular bag. All bags have a zipper, except the Minim 400.
Note: all bags in this table are available in a size Short, though these specs are for a size Regular.
Layer Loft (in/cm)
|Fill Weight (oz/g)||Fill Power||Total Weight (oz/g)||Cost US$|
|PHD Mountain Software||Minim 400||23/-5||2.6/6.6||14.1/400||800||24/680||£235 (approx. US$382)|
|Sierra Designs||Spark 30||30/-1||3.0/7.6||12.0/340||800||25/709||289|
The Nunatak Alpinist at 21 ounces is the lightest bag in this comparison, and the most expensive. The Sierra Designs Spark 30 is rated at 30 F (-1 C), and has the most loft of all the bags listed and the lowest cost, as well as a half-length zipper. Because of the low current (late 2009) exchange rate between the US dollar and the British pound, the PHD Minim 400 is expensive, and the Sierra Designs Spark 30 is perhaps a better value (about US $100 less). Note that buyers outside the UK do not pay Value Added Tax (VAT), so 17.5% is deducted from the price when purchased. However, when the dollar is strong, the Minim 400 is a much better value.
I personally like the PHD Minim 400 because of its simplicity, high loft, and high warmth-to-weight ratio. I don’t mind the bag not having a zipper, because it keeps the bag simpler and lighter. I realize, however, that many people prefer having a zipper for personal convenience and to increase a bag’s versatility. The Minim is available with a full-length zipper option, which bumps up the weight and cost. For a zippered bag, the Sierra Designs Spark 30 (men’s version is the Nitro 30) is a standout. It has the most loft of all the bags listed, which suggests its 30 F (-1 C) rating is very conservative. It’s also the best value.
Specifications and Features
|PHD Mountain Software (http://phdesigns.co.uk/)|
|2009 Minim 400|
|Zipperless hooded mummy (optional zipper available)|
|Sleeping bag, stuff sack, mesh storage bag|
|800 fill-power down, 14.1 oz (400 g) size Standard|
|4 in (10 cm) boxed wall baffles, continuous|
|5.25 in (13.3 cm) average double-layer loft, manufacturer specification not available|
Manufacturer Claimed Temperature Rating
|23 F (-5 C)|
|12 x 6.5 in (30 x 17 cm)|
|Size Short tested|
Measured weight: 1 lb 6 oz (624 g)
Manufacturer specification: 1 lb 8 oz (680 g) size Standard
|Size Standard: Shoulder/hip/foot: 67/58/39 in (170/148/98 cm)|
|XShort fits to 5 ft 1 in (1.55 m)|
Short fits to 5 ft 6 in (1.68 m)
Standard fits to 6 ft (1.83 m)
Long fits to 6 ft 7 in (2.01 m)
XLong fits to 7 ft (2.13 m)
|Optional MX outer shell (tested) is 0.88 oz/yd2 (30 g/m2) mini-ripstop nylon, calendared both sides, DWR finish; standard M1 shell is 40 g/m2; lining is MX Microfiber|
|Seven-panel baffled hood with braided drawcord and cordlock|
|Short and Standard £235 (approximately US$382), Long +7.5%|
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.