How good are Reflectix panels?

[crease]

Have found a few posts on reflective panels and theres seems to be mixed reviews so im hoping someone with previous experience can confirm if they are worth pursuing as a possible shade structure similar to how this person did it.

My tent will be bigger than this, so thats more coverage needed and thinking of attaching them with jump leads.
Also is full coverage required? What if I just covered half of it on the Eastern side to keep the sun at bay until 11am? Or does that logic not work?

Thanks!

[Token]

It a all depends on how good you are at thermodynamics.

In the picture you show, notice the redlectix is a secondary method and the tent is already under a shade structure.

In that particular case, will work OK. Keep the tent cool in the morning but to a limit. If you are in the tent, that reflectix will trap your body heat in the tent equally well. Keeping confined spaces cool would be so much easier if we weren't such productive heat engines.

You have to cover the whole thing. Partial coverage will be a wasted effort/expense. Even a square foot or few of direct sun will make the tent an oven.

Tell more on what you are trying to accomplish.

[crease]

I see. Thanks. Situation is im going via Burner Express solo with all belongings + bike. I would like to minimise what I need to bring and setup were possible. So far the trip has centred around buying, booking, contacting and organising... so far so good, The shade is the one thing I still havent resolved as it requires building, which is fine but without being able to test it out pre-burn I would prefer to go with something more practical in assembly.

Tent im thinking of will be a 6 man one, so was hoping body heat wouldnt be a concern. If full coverage is required as you say then those panels arent the solution, would need more than what I can carry in on my own.

Perhaps I need to just man up build something out of tarp and poles.

[Ratty]

I can tell you that stuff is a miracle on my van windows. I attach it outside with stucco tape. With the back hack and a door open I can nap during the day. It's a bit expensive to cover a tent though. It would also be very bulky to have that much of it.

a 6 man tent is way bulky. Get a smaller one and a sail that goes over it with some retractable poles and ropes.

[Popeye]

Perhaps I need to just man up build something out of tarp and poles.

A lot of people swear by tarps and they do protect from rain. But, they are heavy and catch all the wind which means a heavier frame. Suggest you think about aluminet or shade cloth. Coming in on the bus you will have trouble carrying 10' sticks of EMT. Home depot will cut them to 5' for you and you can buy couplings as well as angle fittings if you plan ahead. Do not try to use standard EMT fittings. No proof but I think the cut and couple idea ia arguably stronger than an uncut piece. The zinc plated steel couplings sold for canopies are pretty strong and reduce flex.

[Canoe]

... reflective panels and theres seems to be mixed reviews ... Also is full coverage required? What if I just covered half of it on the Eastern side to keep the sun at bay until 11am?...

There's mixed reviews because there's many ways that material can be used. Here's some of what can be happening thermally.

• As with tenting elsewhere, for the playa, you want something to keep you insulated from the playa, so at night the ground doesn't suck your body heat away. For example, some people have a cheap rug, rolled up in the day to allow heat inside their shelter to go into the ground, rolled out at night to insulate against the ground. Some years this isn't needed; some years you want any heat possible to go into the ground whenever possible. YRMV
• (For tenting, also think possible rain.)
• If you get a cold night, a reflectix shell over your sleeping bag helps a lot. Insulation and a radiant barrier.
  It's a lot less material to bring than enough to cover a tent, but it doesn't pack as easily as an "emergency blanket" and a polar fleece blanket.
• Some reflectix between your tent and the sunrise would help, but only for a short while.
  Once the sun is up (~6:10 am), it's heating up everything it shines on. The ground quickly becomes hot and radiates heat in all directions, including at your tent from all sides of your tent.
• If you're under a shade structure, you get protection from direct radiation from the sun.
• If you're lucky to be under one of the camps' shade-cloth roofed camps, then the ground immediately surrounding you is also shaded from the sun.
• If they've got walls on their shade structure, then you've also got some protection from the sun-baked ground beyond those walls.
• Nearby structures also provide a block between you and miles of hot radiating ground.
• If they're coated in reflectix, or other radiant barriers (like hexayurt panels), then sun & heat hitting them may be reflected onto your tent...
  Some people report that they baked or were baked by their neighbours.
• Reflectix has a radiant barrier on both sides. It not only insulates in both directions, but heat trying to leave your structure, or that radiated into your structure from hot ground, is going to be reflected down at you.
• There are some rather surprising good results from some dark shade structures, as heat within the structure is absorbed by the shade material (and taken away by breezes) instead of being reflected down at occupants. Even with it absorbing heat from sun and surrounding ground, the net is a cool result for occupants. This seems impossible to design (too many poorly known variables), but some people have lucked out on a working balance of material & design.
  The reason to mention this is that there are some emergency blankets that are bonded to inexpensive tarps. That would be a better shade choice for a tent, as you can set it up with the radiant barrier towards the outside, without incurring a radiant barrier on the inside. Being bonded to the tarp, it also helps prevent crinkling of the radiant barrier, so it maintains more of it's performance after getting blown around in the wind. (such radiant barrier tarps are not good replacements for RV window covers, as in that use, reflectix's inside surface also works as a low-emittance surface)

This is but a sampling of what can be going on, so you can see why there can be varied results, and from different years, and with different nearby structures. A huge YRMV.

The one piece of magic is SHADE.
There are some simple shade structures possible, even using but two poles, but they tend to be low to the ground and may not scale to a six person tent. But perhaps you'd be more comfortable in a smaller tent but with your own shade structure for it. Google epaya for such small shade structures.

[trilobyte]

I'm not sure about how they're used in your neck of the woods, but around here that stuff is used with a few of the local grocery and food delivery companies. Not as a shade material, but to keep the contents inside at whatever temperature they're intended to be served or delivered at. Bang some ice packets into one of those and the ice cream stays cold all throughout the driver's route. Put hot food in it and it stays reasonably warm until arrival. That is, it's just an insulation bag. No better at cooling than it is at warming.

Without a shade structure, the sun's rays would be beating down on it directly for the better part of the day. Yes, lighter and reflective colors do a better job of reflecting away more of the sun's energy than darker colors... but from my experience even a shiny material that's directly exposed to the sun is going to get hot. When that happens, it'll radiate that heat in all directions, including the inside of the tent. It will still continue to do the insulation bag thing, keeping the contents warm longer than if it wasn't encased in it.

If space is such a premium and you haven't already committed to more tent than you need, you may want to reconsider your tent and devote more attention on shade. That, or make peace with the idea that it could very well become unbearably hot in your tent during the day. Every year, plenty of people camp in a tent directly under the sun and manage to survive.. you could be one of them

[DerbyDave 18]

Got a question guys. I'm trying to figure out my shade structure too so all this information is great. One thing I'm not understanding in what you all are saying? What's EMT? I assume it's some sort of pole to put the shade fabric on but what? Are there any other options for poles that might work?

[skippy3k]

Electrical Metal Tubing. Metal tubing found in most hardware stores.

[Roundabout]

Last year, I put Reflectix on the roof of my Springbar tent which was already inside my Costco Carport. Sweet!! I could tell an amazing difference from the moment I put it on. It kept the heat being radiated from the roof of the carport out of my tent.

[Canoe]

... If space is such a premium and you haven't already committed to more tent than you need, you may want to reconsider your tent and devote more attention on shade. ...:

BIG support of less tent, more shade.

But as to how reflectix works:

... to keep the contents inside at whatever temperature they're intended to be served or delivered at... it's just an insulation bag. No better at cooling than it is at warming. ...sun's rays would be beating down on it directly for the better part of the day. Yes, lighter and reflective colors do a better job of reflecting away more of the sun's energy than darker colors... but from my experience even a shiny material that's directly exposed to the sun is going to get hot. When that happens, it'll radiate that heat in all directions, including the inside of the tent. It will still continue to do the insulation bag thing, keeping the contents warm longer than if it wasn't encased in it....:

yes, yes, yes, yes, yes, yes and yes
Which means:

• when there's more heat on one side than the other, it does it's insulation thing. If it's hotter outside, it's insulation works to slow down the transfer of that heat to the inside.
• If you're on the inside providing/generating heat, it will work to keep that inside too. So you've got yourself on one side and the sun & sun-baked playa ground on the other...
• The radiant barriers on each side helps cut down on the heat gain (where there's an air gap to let them act as radiant barriers). On the outside, a radiant barrier reflects the sun's energy (infrared, and visible that would convert to heat), but the BIG difference is a radiant barrier reflecting away the bulk of the heat radiated at it from the sun-baked hot playa ground.
• But it's imperfect at reflecting (max 94% effective, less when crinkled), so it does over time become hot. Just a lot slower than a white paint, which might be at 30%. As well, it gains heat that conducts to it from contact with the hot playa air.
• It's bubble insulation slows the transfer of heat through the material to the inside. The heat that does transfer through to the other side ends up heating the radiant barrier on that side, which fortunately is also low in emmitance (1 - .94 for .06) IF you have an air gap. It's low emmittance of 6% is slow to radiate that heat at the interior. It still conducts that heat to the air next to the surface, but that happens a lot slower than if it could freely radiate that heat.

That makes the material great at improving existing insulation, or in providing a cover for RV windows, etc..
But for a tent, it can be tricky to know where the net effect will be help, not hinder.

In the prior post, note where already under shade, a piece on the top (closest to hottest air inside the shade structure and its sun-heated roof) worked to reflect heat away for a net benefit.

So much of the net effect depends on the exact circumstances.

[Canoe]

... Google epaya for such small shade structures.

Here's links to two styles that are simple, light and rather robust for what they are, and take less space than reflectix for a whole tent:

• I like this one best
  viewtopic.php?f=277&t=57022
• others prefer this style (down side to the south)
  viewtopic.php?f=3&t=40542&start=0#p683773

Points:

• They do a lot for blocking the energy from the sun. Not so much for heat radiating from the hot ground, but you'll get more time in your tent in the morning before the heat drives you outside. Some reflectix (or tarp-radiant-barrier on the side of the tent could help with this. As could being near other structures that will limit how much ground can radiate at your tent.
• There are various recommendations on eplaya for the type/size of tent peg that has a proven record of success on the playa, depending on the scale of your shade structure. Search.
• VERY VERY IMPORTANT Detail: note that in neither, the shade material does NOT go all the way to the ground. In a strong wind, this allows the pressure to escape, reducing the load on your shade structure, reducing the chance of it getting ripped apart.
• IMPORTANT: for the guy-lines for the poles: Use two guy-lines per pole, at offset angles, to secure the pole better to minimize "flapping" around of the pole when the shade material is in a strong wind.

Within reason, they can be scaled up for a larger tent.
viewtopic.php?f=277&t=70367#p1038033
NOTICE the two guy-lines per post and attachment point. As well as well buried tent pegs so people can't get a serious injury falling on them, and lights to help prevent tripping at night.

[crease]

Cheers guys, lots of good advice and learnt some basic laws of science in the process. Think im going to scrap that idea all together.
Regarding the size of the tent, its probably worth readjusting expectations of what is deemed 6 man. The one I posted above is sold as a 3 man which imo is suitable for 1 person and not much else. I camped at festival called Rainbow serpent in Melbourne for 4 nights at 40C in a two man tent smaller than that one and my feet were poking out the end of it (im 5ft 11) I only had small bag with a few items of clothing and nothing else. For BM taking all my luggage into consideration I would either need two of those, one for sleeping and one for storage or else a bigger one for both. The 6 man tents ive been looking at are closer to 4 man imo.

Trilobyte the heat at Rainbow was pretty bad, by 8am I was like a burrito, managed to get away with it though your body has a good capacity to adjust. Im sure i'll be fine and on the plus side, having a tent keeps you out and active.