How to Choose Rainwear

晃晃

The below article is forwarded from http://www.rei.com/expertadvice/articles/rainwear.html

How to Choose Rainwear

Your outer shell does more than keep off rain or snow. Rainwear also protects you from wind and cold. Your choice of rainwear depends on expected weather and climate, your planned activities and your budget.

Types of Rainwear

Rainwear design and fabrics affect the performance and comfort of your outer layer. Rainwear falls into 3 basic categories.

Waterproof/Breathable
Water-Resistant/Breathable
Waterproof/Non-Breathable

Waterproof/Breathable Shells

Waterproof/breathable shells are appropriate for the widest range of activities and weather conditions. Because water vapor (i.e., sweat) is able to escape through the fabric, these shells do the best job of repelling the elements while allowing you to stay comfortable as you work up a sweat. Waterproof/breathable shells feature factory-sealed seams to prevent water from entering through sewing holes. The outer shell features a Durable Water Repellent (DWR) finish that allows water to bead up and roll off before it can be absorbed.

Best uses: Waterproof/breathable shells are used for in technical parkas for skiing, mountaineering and backpacking, as well as more casual rainwear for hiking or around-town use.

Pros: Waterproof/breathable layers are an excellent choice for a wide range of weather conditions and activities. Their combination of breathability and moisture protection means that you can buy a single layer for everything from summer backpacking to backcountry skiing.

Cons: Even waterproof/breathable fabrics have their limits. Exact performance depends on the specific type of waterproof/breathable fabric used, the outside temperature, your activity level and other factors. Waterproof/breathable fabrics are more expensive than other types of outerwear. The DWR finish needs occasional refreshing.

Examples: To create waterproof/breathable fabrics from nylon or polyester, either a laminated membrane or a fabric coating is used. Laminates are typically more expensive, capable of higher-performance breathability. Laminate examples include Gore-Tex®, REI Elements® and the newest technology in the field, eVent™.

Gore-Tex and REI Elements are traditional polyurethane laminates that perform well, though their ability to expel perspiration vapor during extended high-activity levels can become overtaxed. As a result, you can feel damp inside such shells.
The latest option, eVent, uses a proprietary membrane that appears to be highly efficient at allowing perspiration vapor to escape. It's so-called Direct Venting™ Technology can leave active athletes literally steaming in cooler conditions because their body-warmed vapor moves so speedily through the fabric.
Coatings, meanwhile, are an ultra-thin layer of polyurethane that includes microscopic cracks that permit a certain amount of breathability.

Water Resistant/Breathable Shells

These shells serve as breathable outer layers for mild weather, light precipitation and high activity level. They're made of tightly woven fabrics (such as mini-ripstop nylon) that block the wind, and they're also treated with a Durable Water Resistant (DWR) outer finish to make water bead and roll off. They are generally not seam-sealed, and so are not classified as waterproof.

Best uses: Water-resistant/breathable fabrics are perfect for anyone who needs weather protection during strenuous outdoor activities such as running, cycling or Nordic skiing. They're also appropriate in warm conditions where breathability is important and the chance of heavy precipitation is low.

Pros: Water-resistant/breathable layers repel wind and light precipitation while providing excellent breathability to keep you cool when your body heats up. They tend to be lighter, less bulky and less expensive than other shells.

Cons: They are not adequately weatherproof to protect you in harsh conditions or during extended periods of rain.

Examples: This rainwear is typically made of lightweight polyester or nylon, which is tightly woven to keep out wind and light drizzle while allowing water vapor to escape. Most soft-shell outerwear falls within this category.

Waterproof/Non-Breathable Shells

Usually made of a durable, polyurethane-coated nylon or PVC, these economical shells are water- and windproof, making them ideal for light activity in heavy precipitation.

Best uses: Waterproof/non-breathable layers are most commonly used during low-energy activities and when the chance of heavy precipitation is high. Examples include ponchos and vented rain suits.

Pros: Waterproof/non-breathable layers offer ample protection from rain and wind. They are more durable and less expensive than most other outer layer options.

Cons: Non-breathable layers can get extremely uncomfortable with even moderate exercise and outdoor temperatures. The moisture and heat that your body produces cannot pass through the fabric itself so these layers must be cut extremely loose (ponchos, for instance) or they must have generous vents to allow body heat and sweat to escape. This type of rainwear is generally heavier and bulkier than other styles.

Examples: PVC- and polyurethane-coated nylon jackets, pants and ponchos typically make up this type of rainwear.

Rainwear Styles

Once you've decided on the type of rainwear you need, consider your styling options.

Tops:

Jackets: Jackets are shorter than parkas and thus pack down smaller. They provide sufficient coverage when paired with rain pants. Front zippers make them easier to put on and take off than anoraks, but any zipper increases the potential for leaks.
Parkas: Parkas are longer than jackets and cover the hips for better overall protection. Front zippers make them easier to put on and take off than anoraks, but any zipper increases the potential for leaks.
Anoraks: These are pullover-style tops. The lack of a full-front zipper makes them less convenient than a jacket or parka, but it does make them the most weatherproof style.
Ponchos: These are inexpensive, waterproof and allow plenty of ventilation.

Pants:

Full-zip: This offers the convenience of quick changes on the trail and wide openings for boots or shoes.
Pull-on: This less-expensive option provides better protection in steady rain. Again, fewer zippers mean fewer chances for leaks. Many have ankle zips to allow easier changes over boots.

Rainwear Features

Hoods: Integral (permanently attached) hoods offer the best resistance against leaks. Ones that can be rolled up or folded away when not in use are less bulky. The most functional hoods feature elastic cords with toggles that can adjust the hood around your face for better comfort and visibility. Some hoods also have stiffened visors or brims that can be shaped to fit. Look on the back of the hood for tabs that can adjust fit and visibility.

Chin guards: Chin guards are fleece or knit synthetic fabric linings on the inside of the collar that protect your face from zipper abrasion and the wetness or frost that can build up from freezing breath.

Pockets: Lots of pockets make it easy for you to store essential gear items. But keep in mind that pockets increase the weight of a shell and potentially can allow more leaks. Pockets should be easy to reach, easy to open and close, and well protected against leaks. Some jackets feature a Napoleon pocket, a vertically zipped pocket that allows you to assume the posture of Napoleon (who often posed with his hand inside his jacket). We're not sure about Napoleon's rationale, but today this type of pocket is used to secure small items within easy reach.

Linings: Free-hanging nylon or polyester linings are often used to protect waterproof/breathable fabrics from wear and tear. Mesh linings weigh less and breathe better than solid linings but don't offer as much protection. Some outer layers (like 3-layer Gore-Tex®) have lining materials attached directly to the inside face of the outer layer fabric, eliminating the need for a separate, free-hanging liner. More technical jackets feature moisture-wicking linings to increase comfort during high-energy activities.

Vents: Vents enhance a garment's ability to breathe, no matter what type of fabric is used in its construction. The larger the vent, the better the airflow, but the greater the risk of leaks. Typical vents include underarm zippers, mesh-lined chest pockets that double as vents, and mesh shoulder yokes with draft flaps across the upper back.

Storm flaps: Storm flaps are a fabric strip that protect against leaks. They commonly cover front zippers, underarm zippers, full-zip pants and external pockets.

Technical design features: Some rainwear is specifically designed for alpine sports or cold, wet conditions. Look for the following if your planned activities include climbing, mountaineering, skiing or snowshoeing:

Fabric reinforcements: These prevent wear and tear at the seat, knees, elbows or shoulders from pack straps or contact with rocks or snow.
Articulated elbows and knees: Extra fabric at these key spots allows excellent range of motion.
Scuff guards: These protect shell fabric on the inside edges of pant legs from skis or crampons.
Longer sleeves: Extra length keeps arms covered for long reaches while climbing.
Shorter hems: This design allows easy access to a climbing harness.
Drawcord hem or powder skirt: These features seal out wind, snow and rain.

Rainwear Care

When rainwear is new, rain will bead up on the outside fabric of your shell and roll right off. This phenomena is caused not by the fabric itself, but by the DWR (Durable Water Repellent) finish that has been applied to the fabric by the manufacturer.

After regular use, the DWR finish will begin to wear off and your shell will begin "wetting out" in the rain. This means that some of the rain is soaking into the shell rather than beading up and rolling off. It does not mean your jacket is no longer waterproof. The real problem with "wetting out" is that your shell becomes heavier with the weight of the water and, even more importantly, it means the breathability of the shell is getting compromised.

There are a couple of easy ways to renew your rainwear's DWR protection:

Put it in the dryer: The heat of a clothes dryer will temporarily refresh the effectiveness of the shell's DWR finish. Follow the care label of your garment for the correct heat setting to use.
Launder with a DWR-renewing treatment: There are many specialty products available that will restore the effectiveness of the DWR finish in your washing machine. Follow the instructions given with the product when laundering.

丁丁

So long and so hard that I do not understand
I can only support  you

晃晃

引用第1楼丁丁于2009-06-26 16:03发表的  :
So long and so hard that I do not understand
I can only support  you

Thank you! Support is enough.