Tuesday, July 28, 2015

Odds 'N Ends - Lesson from a Tepee

The tepee is such an unique and interesting shelter that it takes two posts to do it justice.Several visitors over the years said things like "Wow, this is cool space" or "I had no idea". Where I am going with this Odds 'N Ends piece is to draw a parallel between the tepee and green building with respect to working with nature instead of against her.  Also, I am betting that most readers have never given tepees much thought and might find the following information interesting.

My late wife, JoAnn, grew up in the country back when there was no indoor plumbing and, early on, electricity as well.  She was only too happy to enjoy the benefits of city living and was not terribly interested in camping, at least until the youngest of our four kids was potty trained ("I am not going to wash diapers in a bucket"). When it was time to begin camping, I researched the subject thoroughly and decided that the tepee was by far the best choice for semi-permanent camping.

Subsequently, our family wore out two tepees between the time our youngest kids were grade schoolers and our grandkids started noticing girls.  We treated them as "permanent" shelters by leaving them in place from year to year rather than moving them around like folks who attend rendezvous on weekends.  The only breaks in this routine in Illinois were for a two week tepee vacation just below the treeline in the Colorado mountains and two years in the north woods of Michigan.

A good downloaded image; the only thing that is
missing are the tethers for the smokeflaps
Ever notice the shape of a tepee?  It's conical so that it funnels smoke up and out during winter and sucks heat out during summer.  It also restricts the amount of unusable space above the living area that must be heated and cooled.  And it allows the poles to be thinner and lighter because a cone (triangle) is the strongest of all configurations. Our tepees were 20' in diameter and 20' tall, fitting the definition of a cone.  There was plenty of room for five army cots around the periphery for seating and sleeping. The middle was used for cooking and clean up with the fire-pit situated between that area and the door.

A tepee always faces east so as to turn its back against the prevailing west winds (northern hemisphere) and to orient the smoke flaps (located just above the door) so that they draw the smoke out most efficiently.

Cover and Liner
The size of the original tepee was limited by the weight of the buffalo skins covering it.  However, when canvas was as close as the next raid on a prairie schooner wagon train, canvas became the cover of choice and allowed tepees to grow.

Hugging the inside of the tepee poles is a liner that runs from about eye level to the ground then turns under against the ground on the inside (notice in the picture how the tepee is darker near the bottom due to the liner blocking the light from the fire).   While the liner is sealed against the ground, the cover is intentionally held off the ground several inches.  This relationship between the cover and the liner creates a natural updraft that carries the smoke out through the smoke flaps.  In summer when cooking is typically done outside, the liner is also raised above the ground in order to improve ventilation.

Smoke Flaps
The smoke flaps are long rectangles projecting a foot or more from the cover above the door, the outside edges of which have rope tethers at the bottom and pockets at the top to receive the ends of two poles.  When the wind is from the north, the ropes and poles are used to tilt the flaps towards the south, much like a person would manipulate his/her coat collar or hoodie against a side wind.  When the wind is from the south, the flaps are tipped in the other direction.  When it blows from the west, the flaps extend due eastward, similar to their position in the photo.   When it rains, the degree of tipping is exaggerated so that raindrops are intercepted by the flaps instead falling on the floor of the tepee or on the fire-pit that lies immediately below the flaps.

When the wind is out of the east, which, fortunately, is relatively rare except just ahead of a front bringing rain or snow, the flaps are tipped like it was raining. Even then, an east wind and falling barometer can make a tepee pretty smokey.  Not only does the smoke have trouble bucking the wind, low pressure keeps the smoke from rising.

Insect Control Without Screens
Insects are repelled by smoke.  Having a fire inside unequivocally precludes an insect problem.  We found during the two years we camped in the north woods of Michigan that even the pesky no-seeums stayed outside at night.   Supposedly, in summer when the fire moves outside, the tepee retains the scent of smoke sufficiently to discourage insects.  However, we did not test this postulate because we disliked summer camping and the hot, humid weather degraded the canvas.  We made it a practice to camp from early September (beginning of squirrel season in Illinois) until early May (end of morel mushroom season) then remove the canvas liner and cover to storage for the summer.

Cold Weather Camping
In mid-life, I went to graduate school.  A patient invited us to move our tepee to his summer compound in northern Michigan during our two-year stay in Ann Arbor.  We had regularly camped in the tepee in winter in Illinois so the second winter in Michigan, we decided to try winter camping there.  The temperature hovered at 15 degrees below zero at night and the snow cover was over two feet deep.  We finally got settled in after digging out the tepee and schlepping our groceries and gear several hundred feet on cross-country skies.  The tepee was surprising comfortable after the fire had burned for a few hours to the extent that we could remove our coats and be comfortable in sweaters.  It did however get cold enough by morning to freeze our eggs despite keeping the fire lit by tossing firewood from under my cot into the fire-pit several times during the night.  By mid-morning we were back to wearing sweaters.  

Tepees Were Better Than Log Cabins

I was not surprised to read years ago that the Native Americans were more comfortable in their tepees than the settlers were in their log cabins, mostly because the shape and size of cabins make them hard to heat.  As the weather grew colder, the Indians untied the bottom of the  liner from the poles and let it hang straight down so as to reduce the area that needed to be heated.  In some cases, a canvas ceiling called an "ozan" was hung horizontally above the living space even with the top of the liner to create a lean-to effect to trap and hold more heat from the fire.  We actually made and used an ozan for winter camping in Illinois but without hanging the liner straight down.  Even then, it made the tepee surprisingly more comfortable on cold nights.