Turning sunlight into hot showers: best kits or hacks?

Mixing valves seemed like overkill to me at first, but after reading up on solar shower temps, I get why people insist on them. I’m still figuring out the best materials for the coil - some folks swear by PEX, but I’ve read it can degrade in sunlight too. Anyone tried copper? It’s pricier, but maybe worth it long-term? My main worry is balancing cost with durability since I don’t want to rebuild the thing every summer...

“Anyone tried copper? It’s pricier, but maybe worth it long-term? My main worry is balancing cost with durability since I don’t want to rebuild the thing every summer...”

Copper’s the gold standard for a reason, but yeah, your wallet’s gonna feel it. I’ve patched up more than a few solar shower rigs where folks went cheap on materials and ended up with leaks or brittle lines after a single season. PEX is fine if you’re keeping it shaded, but direct sun will cook it over time - UV just eats that stuff. Even the so-called “UV-resistant” PEX isn’t immune if you’re in a spot with brutal summers.

If you’re set on not rebuilding every year, copper’s hard to beat. It’ll outlast most of the other parts, honestly. Only real downside is the upfront cost and maybe a bit more hassle bending it into shape if you’re doing a DIY coil. But once it’s in, you’re not going to be chasing pinhole leaks or weird plastic taste in your water.

One thing to watch: copper gets hot fast. That’s great for quick showers, but you’ll definitely want that mixing valve. I’ve seen people skip it and end up with water hot enough to scald. Not fun when you’re just trying to rinse off after mowing the lawn.

If you’re really pinching pennies, black poly irrigation tubing is another hack, but again - sunlight will eventually win. You might get two seasons if you’re lucky, but then you’re back to square one.

Long story short: copper’s expensive, but unless you like fixing stuff every summer, it pays off. Just don’t forget the mixing valve unless you want to turn your shower into a lobster pot...

I get what you’re saying about copper, but man, the price jump is tough to swallow when you’re trying to keep costs down. I’ve used black poly tubing for a backyard setup and yeah, it only lasted me two summers before it started cracking. Still, for the price, I didn’t mind swapping it out. Not ideal, but it got the job done for a while.

“If you’re set on not rebuilding every year, copper’s hard to beat.”

That’s fair, but I wonder if there’s a middle ground. Has anyone tried running PEX inside some kind of cheap conduit or even PVC pipe for shade? Seems like that could give you a few more seasons without going full copper. I’m all about not having to fix stuff every year, but at the same time, dropping a couple hundred bucks up front is a hard sell.

Mixing valve is a must though - learned that the hard way after nearly burning myself last July. If anyone’s got a hack for keeping costs down but still getting decent durability, I’m all ears.

Has anyone tried running PEX inside some kind of cheap conduit or even PVC pipe for shade?

Funny you mention that - I actually did something similar last year. Ran PEX through some leftover 1.5" PVC I had lying around, mostly to keep the sun off it. It’s holding up way better than the poly ever did, and wasn’t a wallet-buster. Not as bulletproof as copper, but for backyard showers and rinsing off after mowing, it’s more than enough.

Mixing valve is non-negotiable though. Nearly gave myself a lobster tan before I figured that out...

I did almost the same thing, but used some black ABS pipe instead of PVC since it was what I had on hand. It’s not pretty, but it keeps the PEX shaded and seems to help with durability. I’m with you on the mixing valve - first time I tried it without one, the water was way hotter than expected. For a backyard setup, this hack makes a lot of sense, especially if you’re watching costs. Haven’t noticed any issues after a year, but I do check for leaks every now and then just in case.

I went the route of coiling black PEX on an old pallet and just covering it with a scrap piece of plywood when not in use. Not the prettiest, but it gets the job done. I skipped the mixing valve at first too - big mistake, nearly scalded myself. Now I just use a cheap garden hose timer to control flow and temp a bit. Haven’t had any leaks yet, but I do keep an eye out after big temperature swings. Funny how these backyard setups end up being more reliable than I expected.

I skipped the mixing valve at first too - big mistake, nearly scalded myself.

Honestly, that's the first thing I look for with these DIY solar setups. Even with PEX, you can get some wild temp swings. Did you notice any weird pressure changes when the weather shifted? I’ve seen some folks get small leaks or even bursts after a cold snap. Also, how’s the hose timer holding up? Some of those cheaper ones don’t always play nice with hot water over time...

Mixing valve was a must for me too - learned that lesson the hard way after a summer day left the water basically boiling. As for pressure, yeah, I noticed it gets a bit unpredictable when the temps drop fast. Had one PEX joint weep a little last winter, but tightening the clamp fixed it. The hose timer’s holding up so far, but I don’t totally trust it long-term with the heat. Might swap to a brass one if it starts acting up. The cheap plastic ones just don’t seem built for this kind of abuse.

The hose timer’s holding up so far, but I don’t totally trust it long-term with the heat. Might swap to a brass one if it starts acting up. The cheap plastic ones just don’t seem built for this kind of abuse.

Yeah, I hear you on the plastic timers. I went through two last summer - both warped after a couple weeks of direct sun and started leaking at the threads. Switched to a brass one and haven’t had a single issue since, even with the midday heat baking it. Costs a bit more upfront, but honestly, worth it for the peace of mind.

Mixing valve is a game changer too. First time I tried my setup without one, the water was so hot it nearly melted my soap... lesson learned. Pressure swings are just part of the deal with these DIY solar rigs, I guess. I’ve found wrapping any exposed PEX with foam pipe insulation helps a bit when temps drop fast - less expansion and contraction.

All in all, sounds like you’re on the right track. These little tweaks make a big difference over time.

I get the appeal of brass, but honestly, I’ve seen those seize up just as fast as plastic if you’re not careful with mineral buildup. Sometimes it’s less about the material and more about keeping things flushed and out of direct sun. Had a neighbor’s “indestructible” brass timer split right down the side after a cold snap - guess nothing’s truly bulletproof. Mixing valves are great, but I’ve had them stick if you don’t cycle them now and then. Just my two cents... sometimes the simple stuff fails in weird ways.

Yeah, I hear you on the brass stuff - folks act like it’s invincible, but I’ve had a couple of those “forever” hose bibs seize up too. Seems like if you don’t keep things moving and flushed, it doesn’t matter what it’s made of. Sun and cold just find new ways to mess with your setup. I’ve started making a habit of cycling everything every few weeks, even in winter. Not perfect, but it’s saved me a few headaches. Sometimes the low-tech fixes are the best we’ve got.

- Totally agree, brass isn’t magic - maintenance is everything.
- Cycling valves and flushing lines every so often really does help, especially with hard water or if you get a lot of freeze/thaw cycles.
- I’ve had “lifetime” hose bibs seize up too, usually after a winter where I forgot about them.
- Sun exposure can be brutal on seals and washers, not just the metal itself.
- Low-tech habits like yours are underrated. Sometimes it’s just about staying ahead of the little stuff before it turns into a big headache.
- Not perfect, but honestly, nothing ever is with outdoor plumbing...

I get the maintenance angle, but honestly, I went with a cheap plastic solar shower bag last summer and didn’t have to worry about valves or brass at all. Just filled it, left it in the sun, and it worked. Not as durable, maybe, but way less hassle for now. If it breaks, I’ll just get another - sometimes simple is fine when you’re just starting out.

I totally get the appeal of just grabbing a solar shower bag and calling it a day. I’ve used those myself, especially when I was first figuring out what worked for my rentals. They’re dead simple, cheap, and if you’re only using them a handful of times each season, they do the trick. I will say, though, after a couple summers, I started noticing the bags would spring leaks or the seams would start to go. Not a huge deal if you’re okay with replacing them every year or two, but it does add up over time.

One thing I ran into - maybe this is just me - was that the water never really got as hot as I wanted unless it was a scorcher of a day. Sometimes you’d get lukewarm at best, especially if you’re showering later in the afternoon. I ended up rigging a kind of hybrid system with some black PVC pipe on the roof and a basic garden sprayer nozzle. It’s not fancy, but it holds more water and gets hotter, plus it’s still pretty low-maintenance. No brass fittings to polish or anything like that.

If you’re just starting out or only need something for occasional use, those bags are hard to beat for simplicity. But if you find yourself wanting something a bit more reliable - or if you’re setting up for guests or tenants - it might be worth looking into something a little sturdier down the line. Just depends on how much hassle you want to deal with versus how often you’ll actually use it.

Funny enough, one of my tenants actually preferred the bag setup because she liked being able to move it around wherever she wanted shade or privacy. Guess there’s no one-size-fits-all solution here...

I tried one of those solar bags for a camping trip and honestly, it was more “tepid rinse” than hot shower. Ended up just using a kettle and bucket half the time. Not knocking them, but I’d rather cobble something together with PVC too. Those bags just don’t last.

Yeah, those solar bags are more like a lukewarm disappointment than a shower. I’ve seen folks rig up black-painted PVC coils and swear by them - ever tried something like that, or is it just as much hassle as it sounds?

I’ve seen folks rig up black-painted PVC coils and swear by them - ever tried something like that, or is it just as much hassle as it sounds?

Tried the PVC coil trick last summer. Honestly, it’s not as much hassle as you’d think, especially if you’re handy with basic tools. The trick is using enough length - like 50 feet or more - and laying it out in a sunny spot. I mounted mine on an old pallet and painted everything matte black. Water gets surprisingly hot, but you do need to run it slow or it cools off fast. Way better than those solar bags, but yeah, not exactly spa luxury either.

I've worked on a few off-grid setups where folks went the PVC coil route, and honestly, it does the job if you keep your expectations in check. The main thing I always warn people about is PVC’s temp rating - most standard stuff isn’t meant for super hot water, so if you get a scorcher of a day, you might be pushing it. CPVC is a bit better for higher temps, but costs more and isn’t as easy to find in big coils.

One guy I know got clever and ran his coil under an old glass window to trap more heat - kind of like a poor man’s greenhouse effect. That actually bumped the temp up another notch, but again, you’ve got to watch out for softening or warping if it gets too hot. Personally, I’d rather cobble together something with PEX tubing if you want a longer-lasting setup. It handles heat better and doesn’t get brittle in the sun.

All that said, for a quick-and-dirty summer shower at the cabin? Hard to beat the simplicity of black PVC on a sunny day. Just don’t expect it to last forever or give you piping hot water after sunset...

- Tried the black PVC coil thing last summer for our first “off-grid” shower. It actually worked, but yeah, water got warm - not exactly spa-level hot, but good enough after a sweaty day.
- Noticed the PVC started to get a little soft by late afternoon, which was kind of sketchy. Didn’t melt or anything, but I kept checking it.
- Thought about switching to PEX after reading a few posts here. Seems more durable, and I like the idea of not worrying if I leave it out too long.
- For a quick rinse after mowing or yard work, honestly, the basic setup did the trick. Wouldn’t rely on it for anything more serious though...

PVC softening in the sun is a classic issue - seen it plenty of times. It’s not really designed for high temps, especially when you’re running dark colors and leaving it out all day. Even if it doesn’t melt, that “sketchy” feeling is justified. Over time, the plasticizers can leach out, and you might notice some weird smells or even taste in the water if you’re using it for anything other than rinsing off.

PEX is definitely a step up for durability and heat resistance. It handles UV a bit better too, though it’s still not perfect if you leave it exposed for months on end. I’d be careful with fittings - some of the cheaper ones don’t hold up well to repeated heating and cooling cycles.

Honestly, for a quick rinse after yard work, your setup sounds fine. If you ever want to go beyond that - like actual hot showers or more frequent use - I’d look into insulated tanks or even those solar shower bags. They’re not fancy, but at least they’re made for the job and won’t sag or leach stuff into your water. Just my two cents...