How to Identify the Best Down Coat for Your Climate Zone

This guide contains the history of the down coat and what to look for in a down coat to find the best for your lifestyle and climate region. Learn what determines the insulation the garment provides and what determines the insulation you need for your activities. After reading this post you can identify the best one for you in a more informed way.

Disclosure: There are affiliate links in this post.

Important notice:  For a definition of terms indicated with * see the High Latitude Style Glossary.

When Was Down Clothing Invented in the US

In 1911, down vests and coats have been produced for the first time in the US. In 1940, Eddie Bauer made a goose-downs quilted jacket to protect him from hypothermia during winter fishing trips. Later during WWII, Eddie Bauer manufactured these jackets for pilots under contract of the Army Air Corps. Back then, cockpits had no heating. After WWII, he used the freed up capacities to extend his production to women’s clothing. Later designers developed  slightly tailored down coats with vertical compartments for a slimming effect and more stylish look. In recent years, the choice of colors increased and down coats with floral or other prints became available.

The goal of wearing a down coat is to stay in thermal comfort for an extended amount of time. People often speak of the “warmth” of the garment, when a scientist would speak of insulation. This term is used in the following.

The Type and Origin of Filling Matters for Its Insulation Capacity

The filling in down coats consists of downs and feathers from geese and ducks. Consequently, the insulation factor of the garment depends on the quality of the downs. Goose downs are better than duck downs. The down to feather ratio affects the insulation. The gold-standard is 90/10. For instance, a label stating 80/20 for the down to feather ratio would mean 80% downs and 20% feathers. Therefore, a 90/10 ratio indicates a better quality and insulation than a 80/20 ratio.

Cheap down coats filled with recycled or low quality feathers provide lower insulation than those produced just with new downs. Furthermore, downs from ducks or geese who lived in cold climate provide the best insulation. Therefore, when you look for top quality, go for Canada goose parkas. Good down coats have a conduction* of 600-700 cuin.

Durable Light-weight Nylon Made a Break-thru in Down Coats

Down vests or coasts are cut from light-weight durable nylon that was developed in 1939. This fabric is tight enough to not let the feather stick thru the fabric like it often occurs with cotton feather bedding. Furthermore, nylon is water repellent. This aspect is important because wet feathers take long to dry, and the drying process would lead to evaporative cooling.

Everyone Needs Outerwear Who Doesn’t Live in the Tropics

Science says that people feel most comfortable in the temperature range of (9^oC to 24^oC). When wearing the right outerwear, i.e., the right insulation, one can stay outside for an extended amount of time feeling comfortable. Note that here comfortable refers to no to slight thermal stress. By no means that this coat could protect you from freezing to hypothermia when you stay outside for an unlimited amount of time.

The right insulation avoids discomfort when watching the aurora or just when waiting for the bus (that tends to be late when a blizzard hits town). The right down jacket permits you to cheer for your favorite dog team in the appropriate Iditarod street style and enjoy other winter outdoor activities like skiing, snow-machining, or dog mushing.

Check the Chamber Structure and Cold Bridges

Any seams are potential cold bridges as here the fabric has only the thickness of the two layers (more on cold gaps in this post). Thus, while quilted down coats keep the downs from accumulating in the lower part of the coat, they also lead to lines of interruption in the insulation. Therefore, the more fashionable body-conscious down coats (see example photos below) that are favored by most women, are less suitable for real Arctic weather with temperatures below -40F (less than -40C) than the Michelin Man like style. Under such conditions, those coats are best that have a horizontal chamber box construction plus and an overcoat like the one shown in the first two photos. This design serves to reduce the impact of these cold bridges.

Go for the Insulation You Need, not More

Down coats are a great way to create insulation when they are well done. The thin air layers between the downs and the pieces of a down hinder the exchange of your body heat with the cold ambient air. This is because air is a bad conductor for heat or in other words, a thin air layer is a good insulator. More downs packed loosely mean a thicker insolation than few down. Like with houses, this insulation should be chosen with the climate of your region in mind. You won’t add the insulation needed for a 5 star energy rated house in Fairbanks, when your house is in Athens, Georgia, for instance!

Filling Power, Weight and Bulkiness

It is well known that thin air pockets or layers provide great insulation. To classify down attire with respect to their insulation, a measure called the filling power is used. The higher the filling power the more air can be trapped in a specific weight of downs. Concretely speaking, this measure gives the amount of cubic inches air that one ounce of down can cover. For example, a filling power of 300 means one ounce of down traps 300 cubic inches of air. The values range from 300 to 900+. On this scale, the increase in insulation increases with filling power. Typically, high-quality garments have filling powers of 500-600.

The bulkiness is a major concern for all fashionistas. Weight plays an important role for women with osteoporosis, as well as for outdoor activities like mushing, hiking, or working. Consequently, at same insulation, a down coat with 300 filling power is heavier and bulkier than one with 900+ filling power.

The Danger of Sweating in Winter

Wearing outerwear that provides too much insolation, namely leads to sweating and hence cooling. You are lucky when you only catch a cold when wearing the wrong coat. Thus, having another jacket with less insulation, in addition to that one for the very frigid weather, is in your advantage regarding your health.

Filling Power and Temperature Range

Unfortunately, not all retailers provide information which coat to choose for which temperature range. The following table reflects broadly a summary of what retailers recommend who provide suggestions. Typically, they claim that the filling is high quality downs with a down-to-feather ratio of 90/10.

40F-60F: less than 400, jackets (Note quilted and leather jackets are a good alternative.)
35F-50F: 400-500, jackets coats
25F-45F: 500-600, 3/4 length coats
10F-35F: 600-650, above the knee length coats
-10F – 10F: 650-750
-20F – -10F: 700-900
less than -20F: 900+

However, they make no statements about whether or not the Sun shines, whether it is dry or humid, on the kind of activity (e.g. standing, walking, sitting), and the duration of being outside. In other words, such tables are only meant as a broad starting line for what to look for in a down coat temperature-wise. Read on what else you have to consider.

Best Insulation Depends on More than Just Outside Temperature

But what is the right insulation you need for a down coat in your region? Whether you will feel comfortable or uncomfortable outside depends on more factors than just the temperature. Relative humidity, the wind and the clothing you wear also affect your thermal comfort level. This means when investing in a down
coat for staying warm in winter you shouldn’t just buy any down coat, but the right one for the typical winter weather of your region.

Wind can Make the Air Feel much Colder than It Actually Is

This phenomenon is called wind chill. To stay comfortable you need outerwear that is chosen with the typical wind chill of your region in mind, instead of just the typical temperature range or climate mean temperature. You can use the wind chill table below to find what the air in your region feels like for the typical temperature and wind speed range of your region. When you just moved there, just call your local National Weather Service office and ask. The diagrams below give the wind chill temperature and hazard range to help you to determine the temperature and adjust the filling power to look for in a down coat.

The temperature values in the chart give how you would feel the temperature. To determine the wind chill temperature, look where the actual temperature and wind speed lines cross. Now look at the temperature range in the previous section again for adjustment.

High Outside Humidity Induces Thermal Discomfort

Like high relative humidity makes hot summer days to uncomfortable dog days, high relative humidity makes you feel uncomfortable at the lower temperature range too. Under high humidity the downs take up humidity which makes the garment slightly more heavier as well.

What’s Best for Whom, When

In other words, a fashionista in northern California is best served with a light downcoat suitable for temperatures down to 30F in the midst of winter, while a fashionista up in the Great Lakes area would wear this piece in fall prior to the first snow. This fact doesn’t mean that when the Great Lake area fashionista shouldn’t buy a 30F rated coat. She just must be aware that it’s a perfect fall coat for her, and she needs another one or has to apply layering to stay warm when the Polar Vortex hits. Actually, she needs both coats.

Down Coats Are a Must-have in the Sub-Arctic and Arctic

While down coats are not very fashionable or stylish, they are crucial for any outdoor winter activities including camping, ice fishing, hiking, snow-machining, cross-country skiing, skiing, watching the aurora and dog mushing. Invest in a down coat when your climate region has temperatures of 40 below zero. I got the one presented in the first photo of this post in 2001, and never looked back cold protection-wise. It permitted me to watch the Iditarod and Yukon Quest starts on the Chena River for two hours without feeling uncomfortable at temperatures in the double negative digits. But I admit, I avoid wearing that “monster” as it makes me look like a dumpling, and it is pretty heavy.

Alaskan insider tip: When you move to Alaska, don’t buy a down coat where you used to live. Buy it in Alaska to get what you really need.

Note when living in Interior Alaska, the continental regions of the Canadian Arctic, or in Central Siberia, you might need attire for the various different temperature ranges. When temperatures don’t tend to go below -40F (-40C) where you live, you won’t need such a heavy coat.

What to Look for in a Down Coat for Mid-latitude Maritime Climate

There exist charts to check which down filling weight is sufficient for various temperature ranges. An aspect what to look for in a down coat for the weather of your region is that it is a wind-resistant, and water proof version.

Note that local topography can lead to wind channeling; close-by lakes may lead to a milder climate in fall than in areas farther away.

In Summary What to Look for in a Down Coat

The most important aspects to identify the best down coat for you are

• The weather conditions (temperature, humidity, wind) for which you intend to wear the garment.
• Cold gaps and compartment structure.
• Nylon compartments. Note that otherwise the quilts stick thru the fabric, which not only looks awkward, but also is uncomfortable.
• What will be your activity level outside? Note that strong movements may ventilate air, and lead to cold ambient air entering thru the cold gaps (sleeves, neck, hem).
• How long you intend to stay outside.
• The quality and origin of the downs.
• The filling amount.
• The conduction value.

Note that people adjust to the weather of their region. This means an Alaskan might wear a 600 filling power 90/10 coat at much lower temperatures than a Californian woman. For example photos see my review of the Happy Goat Lucky Grace.

Further Readings on Wearing Down Coats

Learn more on how to look stylish in down clothes, and on how to create an awesome coat wardrobe that works for your lifestyle. You may also be interested how to wear the down vest trend.

References

Felix, R., 2017. Eddie Bauer: Down Jacket Developer. First in Fashion Series. Abdo Publishing, ISBN: 9781532110733.

Kottek, M.,  Grieser, N., Beck, C., Rudolf, B., and Rubel, F., 2006. World Map of the Köppen-Geiger climate classification updated. Meteorologische Zeitschrift, Vol. 15, No. 3, 259-263.

Mölders, Nicole, 2019. Outdoor Universal Thermal Comfort Index Climatology for Alaska, Atmosphere and Climate Sciences, DOI: 10.4236/acs.2019.94036

Photos of me: G. Kramm

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