“Hot Tenting” is the traditional way to get in out of the deep cold, dry out, relax and luxuriate in the warmth of a woodstove. As the weather drops to below -30, maybe even below -40, and the trees are cracking, and the lake ice is booming, and the wind is howling, you and your buddies are happily inside the big tent in your shirt sleeves enjoying food, beverages, and pleasant conversation in the glow of candle light and headlamps. Your clothing and sleeping gear dries without effort in the beautiful heat. It is an extremely satisfying way to travel and live in the bush in winter.
Hot Tents: The material
“Living under canvas” might be recognized as a phrase from a bygone era. After all, aren’t modern camping shelters now made of hi-tech, space age, gossamer-thin light-weight synthetic materials? Well in the case of hot tents, tightly woven natural cotton canvas is still by far the best material there is for keeping heat in, letting moisture out, packability, and especially because it does not melt!
A wood stove and its pipes get very hot, and modern tent synthetic material like nylon can instantly melt if they are too close, or accidentally touch a hot metal surface. The occasional spark also escapes from stovepipes, and these drifting sparks will instantly melt a hole through nylon on contact. Cotton tent material won’t melt, can get very hot before a fire hazard, and will arrest small sparks.
A huge amount of water vapour is generated inside a tent in winter from breath and drying clothes and sleeping bags. Moisture and frost build up in a tent is no fun. Cotton canvas tent material allows the water vapour to go right through without condensation. The heat will drive it through. Most people let their stove go out during the night and the temperature drops to ambient. Below freezing, exhaled water vapour from breath and your body will frost up on the inside tent surface. When you start up the woodstove in the morning in cotton canvas hot tent, it is amazing how in only a couple of minutes, all the frost disappears, driven through the canvas, or it simply sublimates and is driven out through the vents (more on ventilation later). In a nylon tent, the sudden change in heat can cause a rainstorm inside as the melting frost is trapped inside on the surface material unable to move through it. The humidity skyrockets and its damp inside. Not so in a cotton canvas hot tent.
Cotton “canvas” is a very diverse group of fabrics and they are not all created equal. The gold standard of tent material was and still is Egyptian cotton “sail silk”. Sail silk is not “silk” of course. Historically it’s the material they used to make sails for the tall wooden ships. Sail silk is a very lightweight 3-4 oz weave of the finest Egyptian cotton, which has the longest, strongest, and finest of the cotton fibers. These fibers were woven into extremely tight, very high thread count weaves so that they were windproof. The material feels like a light canvas cotton shirt material, but it’s much stronger and tighter. One of the tests for true sail silk is to hold it up tight to your mouth to see if you can blow through it. True Egyptian cotton sail silk cannot be blown through without a lot of effort. At 3-4 oz weight, it is very light and can be packed up tight to fit on a sled.
Egyptian cotton sail silk is so tight that it will repel water because the fibers swell up and seal it. However modern hot tenters use a white polytarp fly over top which are truly waterproof, and allow snow loads to slide off easier, and polytarp material will arrest sparks and embers. But since the fly is on the outside and separated from the tent roof by an air space, it does not interfere with the breathability of the tent.
Authentic Egyptian cotton sail silk tents are not treated with any fire retardant, waterproofing or preservative. These cannot be legally sold without signing a waiver from the manufacturers, since most countries have laws about commercially available tents meeting some kind of fire resistant standard. All tent material will burn, but retardants slow the ignition process down.
My Egyptian cotton sail silk tent is untreated, natural cotton. Why would anyone in their right mind in this day and age, use a woodstove inside a cotton canvas tent that, if ignited, would go up in a ball of flames in seconds? Well, it actually takes quite a lot of heat to ignite Egyptian cotton. Use of a woodstove inside a tent is predicated on a safety-first protocol that is always respected. Skills are used to make sure than an open flame does not come anywhere near the tent material. The woodstove load is allowed to burn down if leaving the tent for day trips. Never leave a woodstove unattended in tent. Treatment of canvas with a fire retardant and mildew protection doubles the weight of the material, and makes it stiffer, making it a bigger package on a sled. My 4 oz untreated material 8×10 wall tent weighs 18 pounds, and that’s enough! Hence campers resistance to using treated material.
However, an untreated Egyptian cotton tent must be hung and completely dried before storing, and stored indoors in low humidity. Mildew is the enemy! It must be stored in an open mesh bag and should not be placed up against a wall which prevents air circulation. Use of a dehumidifier in summer is highly recommended. Mildew is such a risk for untreated cotton that the sod cloths (band of material around the bottom which is folded out for piling snow on top of to seal out wind and weigh down the walls without needed stakes), are made of burlap on my tent. When stuffed into storage, the burlap will breathe. Sod cloths of polytarp material are popular because snow slides off easily when taking the tent down. But polytarp material inside a packed tent for the summer could potentially trap moisture against the fabric, causing mildew.
Alas, the beautiful lightweight Egyptian cotton sail silk is almost extinct. They don’t make sails out of cotton anymore. “Egyptian cotton” is still a very popular fabric, but its woven for clothing and bedsheets, and the fabric is no where near strong enough for the stresses of a tent. To my knowledge, at the time of writing, there are only two tent makers in North America which make tents in the authentic material, and only one which has a consistent supply, and he makes tents on custom orders only. True tent grade Egyptian cotton is also relatively quite expensive due to its extreme rarity.
One of the holy grails of winter campers is the search for a supply of the real deal: 3-4 oz sail silk or modern equivalent. It is the stuff of legend, and extremely elusive. We have all tried internet searches and come up empty handed. There may be a cotton fabric trade name that it goes by. If you find out, please let us know!
There is one pure cotton material out there which might in fact be the heir apparent to sail silk, should it become extinct: “Ventile” © is made in the UK, and they have sent me fabric swatches, and my opinion the fabric seems to meet the specs of Egyptian cotton sail silk: windproofness, strength, and light weight. The manufacturer also states that Ventile in the outdoors weights is waterproof. Their heaviest weight is relatively heavy and although tents are made from it, it is possible that a lighter tent could be made from their midweight material. Should anyone obtain this material and make a tent from it, please let us know how it performs. http://www.ventile.co.uk/
All that said above about tent grade Egyptian cotton, the good news is that there are excellent modern alternatives that blend the best of the old and the new. Snowtrekker Tents make their hot tents in a beautiful treated fabric that I have used and been extremely impressed with. From their website: “A breathable 6.5 oz. high thread count tight weave cotton duck treated with Sunforger™ Marine water repellent finish and durable flame retardency to CPAI – 84 standards.” The safety factor of this material provides piece of mind and is a significant consideration over an untreated tent. This material remains very flexible for packing down the tent in deep cold to fit on a sled. The treatment is a significant technological advancement over the older treatments, since they meet all safety standards and still manufacture light weight tents that pack reasonably small.
10 oz treated cotton canvas wall tents are readily available from many manufacturers. This common, readily available material is inexpensive, but it’s not tightly woven, and requires a heavy treatment for tightness and any sort of water repellency. The material is quite heavy and bulky, and difficult to work with when setting up and taking down if you are in a hurry. I once owned a 10×12 wall tent of 10 oz treated material and it weighed about 50 pounds, and occupied about 2/3 of an 8 foot toboggan. The fire retardant treatment also had a peculiar smell to me anyway. For motorized vehicle supported camping, or for one-day-in type self propelled hauling, this tent material is fine if you have the sled space, and the price is right. But for self propelled trips on snowshoes and skis, making and breaking camps, this material is very heavy and bulky. However, if you are new to hot tenting, have a tight budget, and can get the tent to where its going, it may be a reasonable option.
Hot tenters tend to be a creative and skilled lot, and many folks sew their own tents. Unable to acquire Egyptian cotton tent material, nor the beautiful material that Snowtrekker has, many folks have designed and sewn hybrid wall tents, using treated 10 oz type of canvas for around the stove area, and nylon type material strong enough for tents (e.g. rip-stop 70 denier), for the back end. Proper venting designed into the roof is essential to get the moisture out, but if properly vented, these home made hybrids significantly reduce the weight and bulk, and might even rival the light weight and packability of Egyptian cotton tents.
Hot Tent Design and Rigging
Hot tents have been around for centuries and there are many designs from all around the world. The ones we are interested in at Winter-camping.ca are the ones that are light weight, relatively easy to set up and take down, and can be packed on a human-hauled sled for self-propelled transport via snowshoes and skis.
There are three main designs which have tended to shake out into modern manufactured designs: The rectangular wall tent, the walled pyramid tent, and the modified wedge/A-frame.
Rectangular wall tents are the roomiest and the most efficient users of space, since sleeping people form rectangles, and the woodstove space is a rectangle. Walls are usually 3-4 feet, and ridge height is usually 6 ½ to 7 feet. The upside is all the useable space and ability to stand up in most of the tent. Clothesline tabs are sewn into the inner roof and along the inner ridge so there is lots of line space for hanging clothing to dry. The down side of rectangular wall tents are twofold: many guy lines are needed, and several poles are needed to rig the tent – a total of 7 poles if there are no trees to supplement the rigging. Long spans of support are needed which requires heavier poles in order to have the proper strength. Carrying steel or heavy aluminum poles on a sled can be prohibitively heavy and bulky, so traditionally poles are cut from the bush. To be strong enough, poles are usually cut from live trees, and hence there is an issue with where this may or may not be OK.
A single long pole is used for the ridge, and it is supported at the rear by two scissor poles, or can be lashed to a tree. Using a tree at the rear, you can get away with using only 3 poles. But be advised that by lashing to a tree at the rear, the ridge can and will move during winds which move the tree’s stem. The front of the ridge pole is supported by two scissor poles. The side walls need to be guyed out. If there are not enough trees and shrubs to guy out to, then two more poles will be needed to guy out to. These side poles are lashed across to each scissor pole front and back. If this is your rig, then the scissor poles must be cut long enough to span out to at least the width of the tent. They must also be well secured deep in the snow, or reinforced on the bare ground so they don’t slip out. If using scissor pole pairs for back and front, then the rig is not self standing yet, and must be guyed out from each end with a strong rope so the rig will not collapse fore or aft. Hence the advantage of one end of the ridge being lashed to a tree, where the rig is rigid and there is no need to guy out each end.
I do not recommend rigging a ridge pole between two trees. In the wind, the trees can sway independently and put great stress on the ridge pole and move your tent in ways that might shake the stovepipe, risking a pipe separation. A ridge rope can be used between two trees, and a mechanical advantage system like a trucker’s hitch or block and tackle is needed to reduce the sway in the rope. The rope must be very strong – strong enough to stretch when the trees sway in the wind. Personally, although I have used a rope ridge rig, I am not comfortable with it and do not recommend it because of the extreme tension needed and the risk of it breaking if the wind picks up.
The ridge pole is tied to the outside of the tent by numerous ridge ties, and so the tent’s ridge is suspended. This design allows for a polytarp fly to go over top of the ridge pole, which creates the all-important air space. The roof of a hot tent gets quite hot: room temperature or higher. This air space is essential for gradual sloped wall tents so that falling snow does not melt. The fly stays cold and if made of polytarp material, the snow will slide off if you rigged it tight.
Rectangular wall tents must be rigged inside the forest out of the wind, since their shape does not shed wind very well. It’s very important to pick your tent site well to be sheltered from any likely high winds. Open country rigged tents are done, and you do see these on the tundra, but they need to be very well guyed out. When running a hot woodstove, you simply cannot have a tent collapse, or you could die in a tent fire. At all costs, you must rig properly so that you are safe. Otherwise you should not run a woodstove inside if your tent is shaking in the wind.
The stove is located in the front, to the left by tradition. The stove is at the front so that traffic in and out the door does not interfere with the living space and bedding at the back. The cold air also comes in through the door, and you don’t want to be sleeping there. The left front gable end is pegged into the snow at the center seam under the peak, so as to create a rigid end gable wall for the stove pipe to be supported in its thimble (usually a thin sheet of aluminum that slides into a sleeve. The thimble has an oval hole cut for the pipe exit angle). The pipe does not come out the roof, although you will see inferior designed tents on the market with a roof pipe exit. This requires a major cut out of the tent fly, more guy lines, and a dangerous hot roof pocket around the pipe for excessive snow/ice loading.
The stovepipe exiting the front gable end is lashed onto the extended ridge pole with a loop of wire. Make sure the pipe is loosely wired and it can slide independently in the wire loop. This is essential if your ridge is lashed to a tree at the back. The ridge will move the entire tent when the tree sways in the wind, and if the pipe cannot articulate separately in the wire loop, it can be pulled apart causing a catastrophic pipe separation inside the tent! Wiring the pipe up above the ridge allows the pipe exhaust to rise up and away from the tent. If there is any blowback with a wind change, it will go over the tent instead of back into the door.
Pyramid wall tents: These can be many sided. One of the key advantages of pyramid tents is that they need only one central pole for support, if there are enough trees and shrubs around to guy out the walls to. It is feasible to carry the pole in take down sections on a sled. Pyramids can be faster to erect than a rectangular wall tent because of one pole, although the bigger ones have almost as many guy lines to rig . However they have less head room and less efficient use of floor space than a rectangular wall tent. There is always that pole in the center to move around, although it can be used to hang gear from. The air space for the fly is usually not as high, so extra care is needed to guy it out tightly so it does not sag into the roof. The design for the door is tricky. The door has to occupy part of the roof and no fly coverage is possible there, and so if it rains this is an area of leakage around the door. The fastening system for the door is also challenging.
Another great advantage of a pyramid wall tent is the ability to shed wind. Multi-sided octagonal or round pyramids are the design of choice for many expeditions in the open unsheltered polar regions due to their wind-shedding ability. If the walls are high and without surrounding trees and shrubs to guy out to however, pickets (short wall poles), are needed to shore up the sides. Pickets are sometimes also needed on rectangular wall tents.
The stovepipe thimble comes out the side wall and then a pipe elbow is used to route the pipe up. This eliminates the need to cut out a fly section for a roof thimble, and also eliminates a dangerous hot snow loading zone around the pipe thimble. The outside pipe is supported by a pole or bi/tripod. Two elbows are needed, one off the stove and one outside.
Great sources of information on detailed wall tent rigging technique (pole configurations, pickets, stove pipe locations, etc), are documented with excellent drawings in:
MacDonald, Craig K. 1989. Instructions for the Odawban Camping Equipment. 38 p. (published independently by the author, and revised from time to time. Superb drawings).
Conover, Garrett and Alexandra Connover. 1995. A Snow Walker’s Companion: Winter trail skills from the far north. Ragged Mountain Press, Camden Maine / McGraw Hill, Ohio. 238 p. (One of the best sources of information on pyramid wall tents, including plans for cutting and sewing your own).
Modified wedge / A-frame: A great modern example of this is the Snowtrekker “expedition” model. The advantage of this design is that the angled sawhorse design of the internal frame means it is self-supporting. There are far less guy outs needed, and so set up and break down time is quick. No poles are required to be cut from the bush. However all poles must be carried, and you must not lose or damage them. Snowtrekker has improved its pole technology and now has very light and low volume aluminum shock-corded poles which make set up and take down quick.
Wedge/A-frames have less headroom than a rectangular wall tent. However Snowtrekker has a design cut where the guyed out sides stretch far out to almost create pseudo walls, providing impressive interior space.
The stove pipe comes out the lower roof requiring only one elbow on the stove. Snowtrekkers come with an integral thimble. Outside a bi/tripod is needed to support the pipe.
Internal frame Snowtrekker tents do not come with a fly. Therefore falling snow will melt on the roof when the stove is going. The fabric is treated to be waterproof and the slope is steep to allow for shedding. I own and use a Snowtrekker Expedition 3-man, but to date, I have not tested it in a big snowfall, so I can’t comment on how well it performs without a fly, nor how easy it is to knock off the ice for packing up the tent. However with the steepness of the roof, I am not too worried. It would be possible to design a custom fly but it would require a cut-out for the stove pipe and extra guy lines. The outside ridge might also need some kind of foam spacer blocks to create an air space. If you have used one of these tents in a heavy overnight snowfall event, please let us know how well it performs in shedding snow off a hot roof. If you have a design for a fly, please post your ideas on our discussion forum.
To dig out or not to dig out:
Where you have deep snow, you have options for making a raised sleeping platform and sitting bench. In a big rectangular wall tent, the traditional method for designing the floor was to dig out a cold well for the stove and entrance, and a raised platform at the back for sleeping on, and a side bench for the cook to sit along the wall to tend to dinner and the stove. At the snow edge a log was cemented into the snow, running outside the tent into cold snow for support. It all sets up solid and provides a sitting bench. The cold well design around the stove also keeps the rest of the tent warmer. By sinking a foot well in deep snow, it also adds lost of head room and is ultimately more comfortable. This is a superior, classic method that works very well.
I tend to be lazy and don’t bother with 2 tier floors. My buddies and I each carry plastic milk crates for sitting on, so we don’t need the benches I pack it down flat, although you can compromise and dig it out flat to add more headroom.
The Floor Covering:
The traditional way to make a floor is to lay down several layers of green, soft conifer species boughs, like black spruce and balsam fir. There is nothing like sleeping and living on a thick spongy dry bed of soft aromatic black spruce boughs. All the snow from your boots and gear falls through it. If you spill food or drink, it falls through it. It creates an insulating air space under your sleeping pad, adding significant warmth to your sleeping system. And they form a latticework which binds the snow so you can stand up and walk on it and not post-hole your floor if built on deep snow.
Way out in the Boreal Forest bush on Crown (public) land in Canada’s Provinces and Territories, far away from any summer campsites, tucked into the thick bush out of the wind, its not a conservation concern to break off some boughs for your floor. The Boreal is driven by huge disturbances of forest fires, huge blow-downs, and insect defoliations. Forest ecosystems south of the Boreal are also disturbance driven, so again, if well away from summer camping areas, its not a conservation issue. However, that said, this is a very difficult issue.
In provincial and national parks, the cutting of live vegetation is generally prohibited, except if special permits or permissions are granted. In the south, there may not be many spruce or fir to begin with, so there can be impacts if the area becomes popular.
Its up to you to make your own decisions and make sure you obey the laws of the land where you travel. Its always best to stay away from summer campsites, which makes sense anyways since summer sites are open to wind to stay cool and keep the bugs off, but in winter these open areas are the last place you want to be. There also likely won’t be any above-snow firewood left around traditional summer sites. You want to be tucked into deep bush to stay out of the wind, and to be surrounded by deadfall firewood. These sheltered areas would be too dark, thick, humid and buggy in summer, so no one will likely know you were there if you pick your spots right.
If you are unable to use black spruce or balsam boughs (white spruce needles are generally avoided because they are sharp and can smell bad when heated), then you may have to use a non-slippery tarp. Polytarp material is a poor choice because it is so slippery. Less slippery flooring material includes material like a very light waterproofed canvas, or Tyvek, or uncoated nylon. Obviously you need as thin and light as possible for hauling and packing considerations. Be careful with cooking, eating and liquids because spills stay on a tarp and you cannot risk soaking your sleeping bag with liquid or grease. Without boughs, you may have to dig snow out and down to make an eating/cooking area so as not to need a floor covering.
Woodstoves are always a great topic of discussion and debate about design and function. They must be small and light enough to pack and haul on a sled. But they need to be large enough to pack the pipe sections in, to hold reasonably large sizes of wood (the larger the tent, the larger the stove needed to heat it), and to support heavy cooking pots on it. The steel must be thick enough gauge so as not to buckle and collapse and burn out, and to survive the rigours of sled hauling, but not too heavy for hauling.
There are few commercial manufacturers making stoves for dedicated sled haulers, although most in the market make good ones. Many fine brands of portable woodstove makes on the market are too heavy for sled hauling, since they are designed for vehicular or horse train supported trips and base camps. Beware the lightweight fold down models, which can buckle and fail. When its dipping to -40 and night is coming on, you can’t be fiddling with trying to make warped pieces of steel try and fit into warped slots. The traditional snow trekker’s stoves are one – piece solid units. The pipe sections fit inside to keep them from being bent, and there may be room also for an elbow or two, although sometimes elbows have to ride outside. Elbows are critical and may not be able to be field repaired if bent, so make sure they are packed securely. Cardboard boxes are often used to pack food on a sled, and these are also a good place to pack the elbows into, to prevent damage.
Stove and Pipe Materials: The steel used for stoves usually ranges from 22 gauge (heaviest) to 26 gauge (lightest). My stoves are 24 gauge, which I have found are a good compromise between light weight, durability, and ability to support heavy pots. 26 gauge to my knowledge is used for smaller stoves designed to support light pots. Having never used a 26 gauge stove, I don’t know how well they old and radiate heat, nor how long they last.
The stoves I own are manufactured and purchased from Craig MacDonald’s Odawban company, which use 24 gauge “black iron” steel sheet. These are painted with black strove paint on the outside. The inside can corrode after use, so after use you need to spray the inside liberally with vegetable oil and coat everything. This will semi-harden into a gum and keep them corrosion free when stored in the warm months. The softer steel is an excellent conductor of heat and can become red hot and radiate so well, that you need to also rig a deflector shield on the front side, or risk cooking your buddies!
Commercial stoves are also made of stainless steel and titanium. I have never used these stoves, but I have never heard a complaint, and they apparently are immune from corrosion. The titanium designs have a significant advantage for lightweight. On the Internet, I have seen reports of people making their own stoves out of galvanized steel. The zinc galvanizing must be burned off and oxidized first outside in a well vented area before using in a tent since the vapours are poisonous. Once oxidized, there no more vapours and they are safe, and no need for painting. Not having used one, I don’t know how well they resist corrosion on the inside and outside.
All stoves however, whether susceptible to corrosion or not, need a false bottom with an air space to prevent bottom burn out. My Odawban stoves have two simple inserts of folded steel (each occupy half the stove bottom, allowing easy extraction for cleaning), with edges about 1 cm or ½ inch to keep them up off the bottom.
Pipes traditionally are made of galvanized steel, 26 gauge, and these can be found fairly readily at hardware stores. They need to be steel pop riveted along the seam to ensure they don’t pop open under extreme heat. The zinc galvanizing must be burned off and oxidized first outside of course before using in a tent. For elbows, make sure you get nothing lighter than a 26 gauge galvanized, and make its riveted, not crimped. Lighter crimped elbows are unsafe. And don’t even think of aluminum pipe or stoves, which will melt! All rivets used in your stove and pipes must be steel (I recommend stainless), not aluminum.
There are some manufactures making excellent titanium stove pipes, and these are lighter than galvanized steel, although more expensive of course. Some manufacturers have also designed tapered nesting pipes which have the advantage of allowing for more pipe sections to be carried (to get the smoke and potential sparks up and away from the tent), and more room for elbows inside the stove.
Stove Feet: Supporting the stove up off the snow floor is obviously important. The stove cannot be allowed to melt snow quickly underneath, otherwise it will sink and pitch, compromising draw, cooking, and possibly leading to catastrophic internal pipe separation.
There are as many designs as winter hot tenters. The older designs like my Odawban stoves have little feet designed to be nailed to skid logs covered by aluminum foil. I however prefer a higher stove and so I made folded sheet steel supports which sit on skid logs (see photo). Modern designs have folding legs, which are a light, efficient, strong design, and allow for inserting skid logs. Folding leg designs also allow an open area under the stove for warming food and water. Unless you have flat ground, you need skid logs to float the stove’s weight across a large snow or uneven ground surface, making it very stable. The old school bush method which saves weight, was to cut 4 stove leg stakes out of green wood, with corner notches to support the stove, hammer them into the ground with your axe, and twist wire the legs together so they are rigid and clamp the stove. More labour and time, but this traditional bush technique lightens the load since there are no stove feet needed to haul.
Cutting Out Pot Holes:
Cooking on top of a sheet metal woodstove can be challenging, especially if the surface beings to warp. Warping of a well made sheet metal woodstove is normal and not an issue to be worried about. You can vastly reduce the time it takes to boil water and cook food if you cut out holes for your pots to fit down inside the stove. Inside the stove, the pots are licked by the flames and immersed into intense heat. Its amazing how woodstoves will draw in around the openings in the surface of the pot cut out, so no worries about smoke escaping, provided you set up your stove correctly to draw well.
You need bail handles on your pots, or other lateral extrusion to ensure that they don’t fall through the hole. Obviously you have to measure and cut the hole to the pot set you intend to use. You can cut concentric rings in steel sheet for your smaller pots. See the photos for details.
Pipe Dampers and Air Intakes:
There is much debate on whether or not a stove needs a butterfly valve pipe damper to control the draw and temperature of the stove. One could almost say there are two types of people in this world…….I am in the camp that a pipe damper is essential for maximum control over the draw, burn rate and stove temperature. All stoves have an adjustable air intake at the bottom to convey fresh air into the front and across the bottom of the fuel load. Some folks are happy with using that control as the only control. Me, I need to have the pipe damper.
I own a high tech EPA rated woodstove in my home and of course I don’t need a pipe damper. I can get precise control with the air intake. But this is a high-tech engineered stove that is super air tight. A winter camping sheet metal stove is low-tech, non air-tight, with unofficial intake draws all over the place, like around the door, and the cut out pot holes. I maintain that you have no control over the burn with just an air intake for a camping stove. A pipe damper provides the all important back pressure which ultimately controls the burn rate. Too fast a burn, and the stove literally roars like a jet engine, forcing a visible flame out the top of the stovepipe. When you have flames coming out the top of the pipe, your gases are burning in the pipe and much of the heat is not entering the tent, which is not what you want. Your pipe exhaust should be even and invisible, showing no smoke, just water vapour condensing well past the end of the pipe. With appropriate back pressure of the pipe damper, most of the gases burn in the stove, not the pipe, and the stove steel captures the heat and radiates it out into your tent. You use less wood more efficiently, and water boiling time is much reduced, and you can even get the stove sides to glowing red hot. Make sure you do not forget your deflector shield or you might accidentally roast your buddies!