A New Way To Test Sleeping Bags
Yosemite National Park, CA, USA
The Ardeth Sleep System Protocol (ASSP) is a way to test the
effectiveness of sleeping bags and similar equipment as insulators or
shelters. ASSP uses tiny sensors and real
people in real conditions.
The European Sleeping Bag Temperature Rating Standard (EN 13537) is the current system for rating the insulating qualities of sleeping bags. The protocol represents a big step beyond the measures that have been available for rating sleeping bags in the past—namely, the estimations given by sleeping bag insulation manufacturers. With the EN 13537 protocol, independent and internationally certified laboratories test the bags using standardized testing methods and a lightly dressed, full-size mannequin. Testing takes place inside a climate-controlled chamber, where the mannequin is heated to mimic body warmth. Air and "skin" temperatures are recorded and used to calculate EN ratings for the bags.
Virtually all mainstream sleeping bag manufacturers are using the standard. But variations in parameters at EN testing laboratories (e.g., differences in the kinds of mannequins, clothes, and sleeping pads used in the test) translate to a potential 20-degree difference between ratings and actual performance. That's a big margin of error if you're trying to get a good night's sleep on a snowshoe backpacking trip! Not to mention that human beings vary widely in their sleeping styles and comfort levels: they perspire and move around, and there are documented differences between the comfort levels of men and women in sleeping bags.
The bottom line is this: The EN13537 standard puts a dry, dead, plastic manikin in a closed-up metal box and runs a test under controlled conditions. The tests cost thousands of dollars for a single sleeping bag and a single test. ASSP is different. Completely different. Our protocol monitors real people in real conditions and costs as much as a cup of coffee. Well, a good cup of coffee.
The European Sleeping Bag Temperature Rating Standard (EN 13537) is the current system for rating the insulating qualities of sleeping bags. The protocol represents a big step beyond the measures that have been available for rating sleeping bags in the past—namely, the estimations given by sleeping bag insulation manufacturers. With the EN 13537 protocol, independent and internationally certified laboratories test the bags using standardized testing methods and a lightly dressed, full-size mannequin. Testing takes place inside a climate-controlled chamber, where the mannequin is heated to mimic body warmth. Air and "skin" temperatures are recorded and used to calculate EN ratings for the bags.
Virtually all mainstream sleeping bag manufacturers are using the standard. But variations in parameters at EN testing laboratories (e.g., differences in the kinds of mannequins, clothes, and sleeping pads used in the test) translate to a potential 20-degree difference between ratings and actual performance. That's a big margin of error if you're trying to get a good night's sleep on a snowshoe backpacking trip! Not to mention that human beings vary widely in their sleeping styles and comfort levels: they perspire and move around, and there are documented differences between the comfort levels of men and women in sleeping bags.
The bottom line is this: The EN13537 standard puts a dry, dead, plastic manikin in a closed-up metal box and runs a test under controlled conditions. The tests cost thousands of dollars for a single sleeping bag and a single test. ASSP is different. Completely different. Our protocol monitors real people in real conditions and costs as much as a cup of coffee. Well, a good cup of coffee.
How it works
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Testers take several sensors, usually three or four, with them on their backpacking trips. A trip package for one person is commonly one card-sized sensor, two button sensors, and a field book.
Most testers will also use a pen, a couple of safety pins a couple of #2 S-carabiners carabiners. When preparing for sleep every night, the tester places the sensors. For example, say that this person is sleeping in a sleeping bag inside a tent. One sensor would be placed in the sleeping bag. Another sensor would be placed in one of the tent's pockets, and a third sensor would be hung outside of the tent. The units monitor the conditions around the tester's skin inside the sleeping bag, outside of the sleeping bag, and outside of the tent. |
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In addition, the sensors have a button on them that allows the creation of a time stamp during recording. So as testers nestle into their bags for the night and prepare for sleep, they push the time stamp button on the sensor inside their sleeping bag to mark the beginning of their sleep period.
As the night progresses, the sensors silently record temperature and humidity. If testers changes clothes, gets up to pee, or zips or unzips the bag, they press the time stamp button again to mark the time. |
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When testers get up in the morning, they hit the time stamp button again to indicate the end of the sleep period. Then, perhaps over morning coffee, they record in a notepad the meaning of any time stamps that they made throughout the night. This data can be recorded for many nights. At the end of the trip, the sensors and the notepad are returned to Ardeth so that the data can be uploaded. Ardeth then summarizes the data and produces a chart showing the comfort perceptions of the testerscompared to the performance of their sleep systems.
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Results
Testers will be able to see how their equipment performed in real-life conditions. They'll be able to see how cold it got at night during their trips and much insulation their sleeping bags, quilts, or blankets provided. They will also be able to see how much protection their tents or tarps provided.
ASSP testers will be able to see how all the components of their sleep system work together and assess their gear's effectiveness. This information provides further insight about gear performance in the context of weight, one of the key components of trip planning for lightweight backpackers. If the temperatures for an upcoming trip are supposed to drop to 30°F, does one take a five-pound tent or a one-pound tarp? A three-pound 0°F bag or a one-pound 30°F quilt? Knowing specifically how gear performs in a system allows backpackers to make informed choices about what to pack.
ASSP testers will be able to see how all the components of their sleep system work together and assess their gear's effectiveness. This information provides further insight about gear performance in the context of weight, one of the key components of trip planning for lightweight backpackers. If the temperatures for an upcoming trip are supposed to drop to 30°F, does one take a five-pound tent or a one-pound tarp? A three-pound 0°F bag or a one-pound 30°F quilt? Knowing specifically how gear performs in a system allows backpackers to make informed choices about what to pack.
Long-term results
The real strength of ASSP is that test data can be combined and compared to measure the performance of sleep systems and individual pieces of gear. One tester in one sleeping bag is informative, but with 10 testers in that same model sleeping bag, we can begin to see its true performance. Testers can also retest their gear years later to measure the effects of use.
ASSP can tell us which sleeping bags rated to 30°F really provide adequate warmth at 30°F? How much protection do tents really provide? How much warmth do women prefer compared to men to be comfortable sleeping in the backcountry?
Have you ever wondered how much of a difference vapor barrier socks make? Or whether draping your rain jacket over your quilt will allow you to ca? For the first time, this information will be up on the web for perusal.
ASSP can tell us which sleeping bags rated to 30°F really provide adequate warmth at 30°F? How much protection do tents really provide? How much warmth do women prefer compared to men to be comfortable sleeping in the backcountry?
Have you ever wondered how much of a difference vapor barrier socks make? Or whether draping your rain jacket over your quilt will allow you to ca? For the first time, this information will be up on the web for perusal.
ASSP helps backpackers tailor their gear to match trip conditions and assess what works best for them.
ASSP provides unique, detailed information to manufacturers.
ASSP helps retailers match gear with their backpacking, survival, SAR, mountaineering and rock-climbing clients.
ASSP helps consumers select gear that is more suited to their age, gender, experience level, or trip style.
ASSP provides unique, detailed information to manufacturers.
ASSP helps retailers match gear with their backpacking, survival, SAR, mountaineering and rock-climbing clients.
ASSP helps consumers select gear that is more suited to their age, gender, experience level, or trip style.
ASSP is in its infancy. We're starting data collection with backpackers right now, although they represent only a small portion of the population that would benefit from the information provided by the protocol. If you are a backpacker and would like to get a free ASSP profile from your next backpacking trip, we'd love to have you on board. Check out the participants page for information about how you can get involved.
