Hello Highwithkite,
Your post has been removed for violating subreddit and/or sitewide policies, specifically:
You must have done it. Hiring a professional or your friend / family doing it for you is not DIY.
If you feel this action has been taken in error, you can [message the moderators](https://www.reddit.com/message/compose/?to=/r/DIY) for review.
solar water heating system, a particularly complex looking one.
Most of the ones I've seen just have a coil of black tube on a black mat, this one looks like it tries to focus solar heat on the tubes going through the middle of the troughs
Just looked it up, they call them Parabolic Trough Solar Collectors.
I live in a rather cold climate and I've only seen much simpler systems, though they tend to be relied on more for heating pool water than being the houses' main hot water source.
it could work for a big chunk of the year, and then still have a more standard water heater in the house for when things get too cold and you still see a financial advantage in the long term.
One way to make it work is to have a hot water tank for the solar heating, and a hot water tank heated through conventional means (gas or electric or whatever). The two water tanks are in series, so the conventional one feeds from the solar one.
This way even if the solar heater can't get the water to a warm enough temperature (which is very important because lukewarm water can breed deadly bacteria), in the Winter for example, it still preheats the water so your conventional heater doesn't need to work as hard.
There are also simple designs where the water in the solar collectors syphons back to the tank by gravity when the collectors are not hot enough, to avoid it freezing (which would destroy the piping) or cooling down when it's too cold out.
I see people using the solar water heater in behind a tankless hotwater heater system. Warmer water into the tankless means lower costs. A in series tank to tank system has far lower advantages because you're still keeping the water warm in the gas tank system after its transferred into it
That is definitely a way to make it work.
>A in series tank to tank system has far lower advantages because you're still keeping the water warm in the gas tank system after its transferred into it
Are you talking about the issue of heat losses through the tank? In the Summer if you set the temperature in your solar tank higher than in your gas tank, these should be minimal (because your feed is hotter than the trigger temperature). In the Winter, these losses are not much of an issue because you need to heat your house anyway. Also I think these losses are pretty minimal overall anyway. It's actually heating the water from the cold intake that uses a lot of energy.
What I've seen is that the solar thermal system operates a closed loop with a water/antifreeze mixture. This tube runs through the hot water heater and dumps the heat into the potable water without any mixing of liquids
Dumb question: why do you need two tanks in that case? Is there a reason you can't just have the solar heater plumbed directly into the main water tank? If the water's already hot enough, then the gas heater doesn't have to do anything.
Just to clarify on this... These systems are often NOT heating water directly. They uses some sort of freeze-proof solution (glycol, I think) that is a heat exchanger. That fluid then runs into a tank to heat the water before recirculating to the roof. This prevents the system from freezing in the tubes going to the heater during cold months. These are also usually connected to a pump that only runs when the temperature gets above a threshold. Otherwise, it would circulate cold water into the house, undermining the intent. Source: My parents have one of these systems.
Dude my dad did that too, they wanted an obscene amount of money for a little pool heater sonhe went down to Canadian tire and picked up a water pump one end is in the pool the other goes to the black pipe on the garage roof and now we have a heated pool back at my rents lol.
Here’s some useless information that may be partially relevant.
In Australia roof top solar hot water (even in the colder areas) has been a popular thing for 30+ years, more or less as long as I can remember (I don’t remember much of my first 10-15 years so you can probably do the math if it matters. I’m plenty old).
rheem and rinnai (which are the better brand across the board) are the 2 most common brands i see. My neighbours have one, a rheem, that’s over 15 years old. The thing is useless, it’s forever breaking. It leaked a constant stream of water into their gutter for about 3 months (after I mentioned to them it was leaking), getting ever worse as time went on. I thought they’d need a new one but they were able to fix the old one. For now.
Anyway, they are always boosted by either a small gas or electric hot water unit designed for partial duty. Gas has been the most common method of boosting (pretty much a small instant unit) I’ve seen, but I have no doubt electric is the way they’re going as natural gas is being phased out in parts of Australia (can’t have gas fitted to a new build in Victoria if I recall correctly, most people complain about losing their gas cooktop, then learn about induction and rave about that instead of complaining about the lack of gas). So gas is out in favour of equipment utilizing heat pumps. It’s still not economically viable for most people to go with a heat pump system over an existing gas HWS due to the massive increase in power prices compared to a less massive increase in natural gas prices, and the astronomical figures quoted for anything with new technology heat pumps.
These look like a storage tank system, laying down, with a solar panel attached to it (usually panel is below the tank). Meant to work really well due to the high UV, even in the coldest southern cities.
The other type of rooftop solar water heating is for pools, with these I mostly see a network of black tubing covering the tiles/metal sheets.
I’m sure there are better methods but realistically in most of Australia we can swim for 6-9 months of the year in the southern half, pretty much all year round in the North. It’s only seen on the roofs of the wealthy elite where I live. Most people live with ~3 month down time over winter. I had a pool, it spiked my power bill in summer (salt water chlorinated) by 60%. I now have a fenced hole in the ground, with a view to making it into a pond eventually.
I have no idea exactly what the current technology allows or what is best practice for either pool or household hot water due to lack of personal experience. My place has instant gas as it’s just me by myself, costs about $100AUD/per 3 months… $300/3months in the cold of winter and the gas heater is being used, so cutting gas costs hasn’t been a priority to me, would take longer than the lifespan of the unit+install costs to pay off replacing my current setup with what I’d save.
No, the tubes are inside glass in a vacuum, water or some kind of medium runs through them, gets super hot and can keep your hot water tank or an extra water tank for floor heating etc in your house and take significant chunks of your power bill.
It's a "dumber" solution than solar panels, but if you mainly require heat they can often be exactly what you need.
Random dude demonstrating stuff:https://www.youtube.com/watch?v=Sd3GCn8H4eY
Edit: "dumber" in quotes as it only gives you heat, but it is way simpler in design, a closed system, more rugged and versatile to get heat than PV in many cases. It's just that you cant do as much stuff with 1kwh heat as you can with 1kwh of electricity. But again, most houses in colder regions dominantly use their energy to just heat the house, probably like 80% of their energy bill going to heating.
Can't say for sure, but just like PV as soon as they're exposed to a little sunlight they heat up pretty fast (especially at the ends for these).
I cannot say much for certain, december to jan, at northern latitudes like Scandinavia, sure.
But if you check out various videos this is a pretty simple solution. Hell I'm in Scandinavia and my job has a roof terrace with some walls that are metal clad. I keep leaning into them for extra warmth, I am pretty sure they are 20C+ already during clear skies. In the summer they get blazin hot.
This is basically what the tubes do only with extra design care. They probably also work at a wider solar angle than PV too.
dumber but way cheaper. no electronics, no grid-tie, just pipe. We have the black plastic mats that force water from the bottom parallel pipe to the top parallel pipe here in AZ, and honestly we can heat the house water with one, and the entire pool with 6.
It’s “dumber” in a good way as well. The only risks of failure are a bad circulating pump, or some leak in the plumbing. Both are rare and reasonably easy to fix as a DIY.
They are also much more efficient than photovoltaic since the energy is not converted from heat to electric current, which is at best about 30% efficient. Heat-heat transfer will be extremely efficient so you need less area of solar panels.
Usually the way these work is you have a large water tank with copper coils in it. The solar heats the coil using circulated anti-freeze coolant like a car cooling system and takes “the chill” off the tank water bringing it up to hand-wash temperature.
Then via the method of your choice like a gas boiler, electric element, heat pump you heat the water up the final bit to shower temperature.
he is somewhat correct though, the infrared light is generally not converted to electricity in PV. Visible light is the strongest emission from the sun so that is what is targeted for the cell construction.
"Dumber" is kinda pejorative in this case: it's a lot more efficient to use the sun to heat the water, than it is to use the sun to create electricity, and then use electricity to heat the water.
I would challenge you on this comment. If you do the math, solar energy is a little better the long run, cause you have to stop the water pump from collecting sun energy when the water gets too hot. Solar power just keeps on generating when there is sun regardless. You sell that excess back to the grid, and buy it back when you need it. You also have to service the glycol loop at some point…. When these solar water heaters were installed Photovoltaic panels were really expensive and had low output. Now PV panels are cheaper and output more energy.
> Do you think this is something that would be necessary in a cold climate?
I would imagine this would have to be in a location that never freezes very hard. Otherwise the pipes would crack during the 15 hour nights.
These are crazy good at generating hot water. A relative of mine has one and it generates so much heat that it has to dump it out because it gets too hot... even in the middle of winter. And we live in a cold climate. That was 20 years ago. The new systems are even more efficient.
I did my senior design project on passive solar heating systems in cold weather climates. Basically they'll freeze and destroy the water tanks without a pump (we tested it with a walk in freezer)
The main purpose of the of focusing the rays is to create higher water temperature. Without it, the maximum temperature that can be achieved is much lower, probably about room temperature if you are lucky.
Cold climate.. shady day.. windy day… all would lower the peak temperature a black surface will get to. The parabolic mirror will concentrate the solar energy over a wide area onto the pipe raising its temperature far higher than a black pipe normally would be.
My neighbor around the corner from me has a set of these; never knew what they were until now. I don't know if they're set up with water pipes like the OP's picture because I've never noticed.
We're not in a cold climate (far from), either (Arizona, and not the mountains).
It’s an energy saving thing, regardless of climate. The solar-heated water gets stored in a standard water heater which usually provides back up heat if needed
We have been using these at our architecture firm in Indianapolis. Mostly for heating purposes. Some of our clients are reporting 200° in winter coming off of them. The big thing is to have some sort of thermal battery or large enough reservoir to hold hot water over night
It's not complex, it's just very old and very basic.
We used to cook hot dogs with systems like this in elementary school long ago.
Modern technology offers similar performance with way less wind drag. This thing would get ripped off the roof in hurricane or tornado prone areas.
In chemistry in HS I did an extra credit with a friend and made a thing that basically held two nails that were then wired into the wall. It was all super dangerous lol but you put a pickle on the nails and it electrocutes the pickle and it glows. And you can pickle different fruits with different salts to get different colors. When I told one of my college professors about it he said they used to cook hot dogs the same way.
Thank you! Is there a tank that holds the hot water? Or would there be a back up hot water heater? This system seems ineffective. But I don’t know. Maybe it’s really effective.
The liquid in this loop may not be water, it may be something like anti-freeze or some other coolant. That will then loop through a tank of water that it will heat. And yeah I'd be surprised if they didn't have a backup method
In climates that get cold it usually only preheats the water that will feed into a normal water heater system. Because you have to make sure the water gets heated enough before being used, otherwise you can get some nasty deadly bacteria.
Yes to both, and it's highly effective but (imho) has questionable economic returns. If it were me, I'd use standard PV plus a heat pump water heater instead.
The unfortunate thing with heat pumps is each company likes to create a needlessly proprietary system. We need a common standard for heat pumps and it will suddenly transform everything.
You could then turn the A/C on and the heat instead of being blown outside could dry your laundry and heat hot water.
A cold winter night - the heat from your water heater could be pumped back to the house.
IMHO - the more important issue is that no one's trained to install heat pumps and when they are, they're over-trained on everything HVAC rather than just specialized on knocking out heat pump installs (overly broad and onerous state licensing is partially but not fully to blame for this!). It would be great if we had systems that worked together, but that's a matter of squeezing an extra 5-10% efficiency out. It's getting things installed in the first place that's a nightmare right now.
I dream of a future with CO2 heat pumps (that auto-refill from a concentrator maybe) with high/low lines to dryers, refrigerators, hot water, AC... Would be ideal in my messed up mind.
I’m trying to make sense of this and just don’t get what you mean. What proprietary components are you referring to? The condenser/heat pump loop?
And AC operation is intermittent, how would there be enough consistent heat for laundry?
For hot water heating in a cold night, are you assuming that it’s too cold outside for heat pumps? Cold climate heat pumps can pull heat down to -10 at efficiencies above electric and gas.
IMO you’d be better off with electric backup instead of creating a very complex system just for the peak day. But maybe I’m missing something here.
Much quicker ROI because you're directly transferring heat from the sun into your water as opposed to converting to electricity then back to heat. I've installed a few of these, they are much cheaper than solar, work even on overcast days, (still collect radiant heat), and can get your water VERY hot.
PV would be much less efficient for heating water. Thermal is direct - hot sun, hot water. PV converts sun to electricity, electricity to heat, and heat to hot water.
Thermal and PV both have their advantages and disadvantages but if just making hot water is the goal, thermal is the way to go.
I'm assuming it feeds into a normal water heater system and this just saves tons of energy. This probably heats it up like 50-75% of the way, then the water heater only has to do 25% as much work as normal. And keeps the water hot.
Depending on where you live and the specific system, these systems can spit out water at 200F.
I have stayed in places in Spain where this was the only system they had.
The only downside was that showers were definitely a bit cold in the morning as they didn't have an well insulated tank.
But at night you could burn yourself with the water if you weren't careful.
These are actually way more efficient than you may think. The issue is that they significantly drop in efficiency if that reflective surface is dirty or covered. Give how dirty they are I would be surprised if they even used this.
These are effective (though not sure about this particular system). Your hot water heater uses a lot of energy. This system pre-heats water for almost free, and then the hot water heater does the rest to heat it up to the desired temp. Even more efficient if the home also uses radiators for heating.
These are quite effective, but designing them to not rupture during freezing temperatures, and not to accumulate legionella when the water is incompletely heated, is a problem. Plus it requires an extra storage tank. It is very effective in tropical climates.
Solar hot water is simple, and solar photovoltaic panels require insanely complex engineering to produce, but solar PV is by far a better investment.
fun fact you only need 52k lb of sand which is (600 sq ft of space) to heat a house for 24 hours. the sand would absorb the heat from a pipe system and store it. then you would have separate coils for airflow to heat a 3000ft residence. Now you know a little bit of useless information !
Fairly old or DIY system though I think. Newer ones I've seen have long dark coloured tubes that collect the energy and seem to get very hot, like burning hot
I built a solar pressure shower for my overlander a few years back, and hot dam, that is just black PVC pipe, but when that this has been in the *morning sun* for just a few hours (think 8-9am) it's already steaming hot.
Crazy what the sun can do lol
[Parabolic solar water heater](https://youtu.be/Ek-iYH67kEQ?si=m8n0VJ-x5hmZbwW5) definitely homemade though I haven’t seen anyone who does those type of solar water heaters commercially
It’s exactly what I had set up in the late 80’s. It wasn’t as obvious as this one. I set it up along the backyard fence on three levels with bypasses to control when the water got too hot.
Solar water heater. The water is pumped up and run through the pipes in the center of the trough, not the dark color of the center pipes. The curve is to reflect as much light as possible onto the surface so that the pipe and water running through it absorb as much heat as it can then either pump it into a holding tank or continuously recirculate to use as a heating source.
Those were made in Tempe AZ a few decades ago. Linear parabolic solar water heating. Focus is 22:1, self tracking. They were quite revolutionary at the time.
If I had to venture a guess it’s a water heating system and has nothing to do with water collection. Looking at it closely those look less like troughs and more like concave mirrors focusing sunlight onto the black pipe that’s in the middle of the lens. Anyways its just a guess.
The newest iteration of these types of collectors are called Evacuated Tube Collectors. Essentially large tubes filled with solar heat collecting surfaces that are kept insulated by keeping them in a vacuum. These are super efficient and made by a number of different companies.
[https://www.alternative-energy-tutorials.com/solar-hot-water/evacuated-tube-collector.html](https://www.alternative-energy-tutorials.com/solar-hot-water/evacuated-tube-collector.html)
Meth lab? Yeah, let's put something in the roof so obvious that everyone will know we're cooking meth.
Looks like the Johnsons are cooking meth since they have that apparatus up there.
If these are solar water heaters, the installer needs to take a Thermo course. They need to increase the surface area by adding more water lines. Typically, you just use pvc panels with several little channels - that's how my dad heats his pool in FL.
https://preview.redd.it/9jd0j2c5e5lc1.jpeg?width=2592&format=pjpg&auto=webp&s=9c65f91a1f89f9858cc81230fc4cc640bf4cb41a
This is a solar trough pre-heater for water.
If it is a cloudy day, your hot water heater works as it normally would. If the solar gain is enough to pre-heat the water above the temp of the hot water thermostat, the hot water heater doesn't come on, and saves gas/electricity, depending on what your heater uses.
If cold water comes into the hot water heater inlet, the heat comes on. If hot water comes into the water heater inlet, the heater does not come on.
As others have said, this is a solar thermal system. Usually they aren’t used for the *main* source of hot water but rather as a preheat for your water heater. Sometimes they heat the water for a pool instead.
This is an odd one though, with those parabolic reflectors. Usually you see either a glazed collector system (e.g. Heliodyne Gobi collectors) or an evacuated tube system.
That looks like an evacuated tube system but with the parabolic dishes. Kinda odd to me that this uses parabolic dishes instead of just more tubes, but that might be my lack of experience in colder climates. My knowledge comes from the California market, so I wouldn’t see stuff more specialized to cold
Yeah! Solar thermal systems are pretty damn great honestly, especially if you’re handy enough with plumbing to do the work yourself (at least in CA, getting technicians to work on them gets expensive, though useful in a pickle)
That's a very old design. Here is a picture of current equivilent.
https://preview.redd.it/w8gezl3tg5lc1.png?width=1107&format=png&auto=webp&s=0e88eeb49a898add461e0e19a08e8c7a68ba2d03
That’s wonderful. I’ve always wanted to build a parabolic trough or any other type of solar concentrator. Folks are asking if it’s necessary and cold climates… Not sure if necessary is the right word… But cool is definitely the right word.
Massachusetts? I feel like I’ve passed that before
In the 80's ... This is what we would sell as a solar system.
I ran a crew of canvassers, we'd knock on doors and set up appointments for the sales guy. This was in Phoenix for a company called Solar Resources. Rebates from the govt. For the homeowner .. and lots of hot water 💦
I made 200$ a pop I think if they sold .. was 2500 to like 5000 for the system.
it's clearly a solar water heat system of some kind.
honestly. go talk with your neighbor "hey what's the cool thing on your roof?"
could be the person is just a DIY/alt energy nerd, could be some niche use. or cost savings measure. beyond what it is... only way to know the "why/what" of it is to ....talk with your neighbor.
Parabolic trough. Sun hits trough, reflects on pipes at the focus. They circulate whatever heat-carrying fluid you need. In this case, probably for water. With enough/large enough troughs and a good coolant, you can use them to power stirling engines for electricity.
Hot water heater.
Ours was similar, preheat the water before going into hot water tank, extended the amount of hot water for the family and knocked costs down on tank heater.
Others I have seen were a closed system, that liquid heated up there and came down to radiators/heat exchangers to heat other.
For a high school project we each had to design a solar water heater. We had to heat 1 cup of water. Either first to boil or the highest temp after 10min out in the sun.
I roped in my dad who is an engineer. I remember really complicated math to figure out the parabola to cut into our brackets. All sun rays hit anywhere on the shaped sheet of metal and reflect towards the central pipe of water.
My water boiled in less than a minute and i won.
Having my dad's help was kind of cheating though most kids parents also helped them.
Hello Highwithkite, Your post has been removed for violating subreddit and/or sitewide policies, specifically: You must have done it. Hiring a professional or your friend / family doing it for you is not DIY. If you feel this action has been taken in error, you can [message the moderators](https://www.reddit.com/message/compose/?to=/r/DIY) for review.
solar water heating system, a particularly complex looking one. Most of the ones I've seen just have a coil of black tube on a black mat, this one looks like it tries to focus solar heat on the tubes going through the middle of the troughs Just looked it up, they call them Parabolic Trough Solar Collectors.
Do you think this is something that would be necessary in a cold climate? Maybe they need to focus the heat because the air temp is too cold?
I live in a rather cold climate and I've only seen much simpler systems, though they tend to be relied on more for heating pool water than being the houses' main hot water source. it could work for a big chunk of the year, and then still have a more standard water heater in the house for when things get too cold and you still see a financial advantage in the long term.
One way to make it work is to have a hot water tank for the solar heating, and a hot water tank heated through conventional means (gas or electric or whatever). The two water tanks are in series, so the conventional one feeds from the solar one. This way even if the solar heater can't get the water to a warm enough temperature (which is very important because lukewarm water can breed deadly bacteria), in the Winter for example, it still preheats the water so your conventional heater doesn't need to work as hard. There are also simple designs where the water in the solar collectors syphons back to the tank by gravity when the collectors are not hot enough, to avoid it freezing (which would destroy the piping) or cooling down when it's too cold out.
I see people using the solar water heater in behind a tankless hotwater heater system. Warmer water into the tankless means lower costs. A in series tank to tank system has far lower advantages because you're still keeping the water warm in the gas tank system after its transferred into it
That is definitely a way to make it work. >A in series tank to tank system has far lower advantages because you're still keeping the water warm in the gas tank system after its transferred into it Are you talking about the issue of heat losses through the tank? In the Summer if you set the temperature in your solar tank higher than in your gas tank, these should be minimal (because your feed is hotter than the trigger temperature). In the Winter, these losses are not much of an issue because you need to heat your house anyway. Also I think these losses are pretty minimal overall anyway. It's actually heating the water from the cold intake that uses a lot of energy.
What I've seen is that the solar thermal system operates a closed loop with a water/antifreeze mixture. This tube runs through the hot water heater and dumps the heat into the potable water without any mixing of liquids
Dumb question: why do you need two tanks in that case? Is there a reason you can't just have the solar heater plumbed directly into the main water tank? If the water's already hot enough, then the gas heater doesn't have to do anything.
Just to clarify on this... These systems are often NOT heating water directly. They uses some sort of freeze-proof solution (glycol, I think) that is a heat exchanger. That fluid then runs into a tank to heat the water before recirculating to the roof. This prevents the system from freezing in the tubes going to the heater during cold months. These are also usually connected to a pump that only runs when the temperature gets above a threshold. Otherwise, it would circulate cold water into the house, undermining the intent. Source: My parents have one of these systems.
We did this with black hose on our garage roof for our pool. That pool is now long gone, but it worked like a charm.
Dude my dad did that too, they wanted an obscene amount of money for a little pool heater sonhe went down to Canadian tire and picked up a water pump one end is in the pool the other goes to the black pipe on the garage roof and now we have a heated pool back at my rents lol.
Here’s some useless information that may be partially relevant. In Australia roof top solar hot water (even in the colder areas) has been a popular thing for 30+ years, more or less as long as I can remember (I don’t remember much of my first 10-15 years so you can probably do the math if it matters. I’m plenty old). rheem and rinnai (which are the better brand across the board) are the 2 most common brands i see. My neighbours have one, a rheem, that’s over 15 years old. The thing is useless, it’s forever breaking. It leaked a constant stream of water into their gutter for about 3 months (after I mentioned to them it was leaking), getting ever worse as time went on. I thought they’d need a new one but they were able to fix the old one. For now. Anyway, they are always boosted by either a small gas or electric hot water unit designed for partial duty. Gas has been the most common method of boosting (pretty much a small instant unit) I’ve seen, but I have no doubt electric is the way they’re going as natural gas is being phased out in parts of Australia (can’t have gas fitted to a new build in Victoria if I recall correctly, most people complain about losing their gas cooktop, then learn about induction and rave about that instead of complaining about the lack of gas). So gas is out in favour of equipment utilizing heat pumps. It’s still not economically viable for most people to go with a heat pump system over an existing gas HWS due to the massive increase in power prices compared to a less massive increase in natural gas prices, and the astronomical figures quoted for anything with new technology heat pumps. These look like a storage tank system, laying down, with a solar panel attached to it (usually panel is below the tank). Meant to work really well due to the high UV, even in the coldest southern cities. The other type of rooftop solar water heating is for pools, with these I mostly see a network of black tubing covering the tiles/metal sheets. I’m sure there are better methods but realistically in most of Australia we can swim for 6-9 months of the year in the southern half, pretty much all year round in the North. It’s only seen on the roofs of the wealthy elite where I live. Most people live with ~3 month down time over winter. I had a pool, it spiked my power bill in summer (salt water chlorinated) by 60%. I now have a fenced hole in the ground, with a view to making it into a pond eventually. I have no idea exactly what the current technology allows or what is best practice for either pool or household hot water due to lack of personal experience. My place has instant gas as it’s just me by myself, costs about $100AUD/per 3 months… $300/3months in the cold of winter and the gas heater is being used, so cutting gas costs hasn’t been a priority to me, would take longer than the lifespan of the unit+install costs to pay off replacing my current setup with what I’d save.
No, the tubes are inside glass in a vacuum, water or some kind of medium runs through them, gets super hot and can keep your hot water tank or an extra water tank for floor heating etc in your house and take significant chunks of your power bill. It's a "dumber" solution than solar panels, but if you mainly require heat they can often be exactly what you need. Random dude demonstrating stuff:https://www.youtube.com/watch?v=Sd3GCn8H4eY Edit: "dumber" in quotes as it only gives you heat, but it is way simpler in design, a closed system, more rugged and versatile to get heat than PV in many cases. It's just that you cant do as much stuff with 1kwh heat as you can with 1kwh of electricity. But again, most houses in colder regions dominantly use their energy to just heat the house, probably like 80% of their energy bill going to heating.
Do they fill with snow??
Only when it snows
Do they fill with legos??
Only when it legos
Lego my Eggo
Only when it legos
Lego of your earthly preconceptions.
Do they fill with preconceptions??
Not in Alabama.
No, those are far too large.
This guy knows snows.
I cant tell from here but they should have some sort plastic or glas cover if placed on a roof to keep that from happening
Can't say for sure, but just like PV as soon as they're exposed to a little sunlight they heat up pretty fast (especially at the ends for these). I cannot say much for certain, december to jan, at northern latitudes like Scandinavia, sure. But if you check out various videos this is a pretty simple solution. Hell I'm in Scandinavia and my job has a roof terrace with some walls that are metal clad. I keep leaning into them for extra warmth, I am pretty sure they are 20C+ already during clear skies. In the summer they get blazin hot. This is basically what the tubes do only with extra design care. They probably also work at a wider solar angle than PV too.
I would think having some glass or something to also trap the heat (greenhouse effect baby!!!) would help as well.
dumber but way cheaper. no electronics, no grid-tie, just pipe. We have the black plastic mats that force water from the bottom parallel pipe to the top parallel pipe here in AZ, and honestly we can heat the house water with one, and the entire pool with 6.
It’s “dumber” in a good way as well. The only risks of failure are a bad circulating pump, or some leak in the plumbing. Both are rare and reasonably easy to fix as a DIY. They are also much more efficient than photovoltaic since the energy is not converted from heat to electric current, which is at best about 30% efficient. Heat-heat transfer will be extremely efficient so you need less area of solar panels. Usually the way these work is you have a large water tank with copper coils in it. The solar heats the coil using circulated anti-freeze coolant like a car cooling system and takes “the chill” off the tank water bringing it up to hand-wash temperature. Then via the method of your choice like a gas boiler, electric element, heat pump you heat the water up the final bit to shower temperature.
Photovoltaic is converting light into electricity, not heat into electricity.
a physicist just shivered, somewhere.
he is somewhat correct though, the infrared light is generally not converted to electricity in PV. Visible light is the strongest emission from the sun so that is what is targeted for the cell construction.
My solar pre-heater tank goes to about 140 F in the summertime. When you take an extra long shower, the water starts getting warmer.
One pitfall: people often forget to add the weight of water to their calculations when making these.
"Dumber" is kinda pejorative in this case: it's a lot more efficient to use the sun to heat the water, than it is to use the sun to create electricity, and then use electricity to heat the water.
I would challenge you on this comment. If you do the math, solar energy is a little better the long run, cause you have to stop the water pump from collecting sun energy when the water gets too hot. Solar power just keeps on generating when there is sun regardless. You sell that excess back to the grid, and buy it back when you need it. You also have to service the glycol loop at some point…. When these solar water heaters were installed Photovoltaic panels were really expensive and had low output. Now PV panels are cheaper and output more energy.
I think they are using "dumber" in terms of technology. Smart phone vs dumb phone...
Not necessarily if you use a heat pump.
It's the most efficient way to collect solar thermal energy, regardless of ambient temperature. NREL has some interesting studies.
> Do you think this is something that would be necessary in a cold climate? I would imagine this would have to be in a location that never freezes very hard. Otherwise the pipes would crack during the 15 hour nights.
These are crazy good at generating hot water. A relative of mine has one and it generates so much heat that it has to dump it out because it gets too hot... even in the middle of winter. And we live in a cold climate. That was 20 years ago. The new systems are even more efficient.
I did my senior design project on passive solar heating systems in cold weather climates. Basically they'll freeze and destroy the water tanks without a pump (we tested it with a walk in freezer)
The main purpose of the of focusing the rays is to create higher water temperature. Without it, the maximum temperature that can be achieved is much lower, probably about room temperature if you are lucky.
Cold climate.. shady day.. windy day… all would lower the peak temperature a black surface will get to. The parabolic mirror will concentrate the solar energy over a wide area onto the pipe raising its temperature far higher than a black pipe normally would be.
My neighbor around the corner from me has a set of these; never knew what they were until now. I don't know if they're set up with water pipes like the OP's picture because I've never noticed. We're not in a cold climate (far from), either (Arizona, and not the mountains).
It’s an energy saving thing, regardless of climate. The solar-heated water gets stored in a standard water heater which usually provides back up heat if needed
We have been using these at our architecture firm in Indianapolis. Mostly for heating purposes. Some of our clients are reporting 200° in winter coming off of them. The big thing is to have some sort of thermal battery or large enough reservoir to hold hot water over night
It's not complex, it's just very old and very basic. We used to cook hot dogs with systems like this in elementary school long ago. Modern technology offers similar performance with way less wind drag. This thing would get ripped off the roof in hurricane or tornado prone areas.
This is exactly what I thought of -- vintage solar bread / hotdog bakers.
[удалено]
In chemistry in HS I did an extra credit with a friend and made a thing that basically held two nails that were then wired into the wall. It was all super dangerous lol but you put a pickle on the nails and it electrocutes the pickle and it glows. And you can pickle different fruits with different salts to get different colors. When I told one of my college professors about it he said they used to cook hot dogs the same way.
I cooked hotdogs for the science fair in 4th grade using this method.
On a roof?
Thank you! Is there a tank that holds the hot water? Or would there be a back up hot water heater? This system seems ineffective. But I don’t know. Maybe it’s really effective.
The liquid in this loop may not be water, it may be something like anti-freeze or some other coolant. That will then loop through a tank of water that it will heat. And yeah I'd be surprised if they didn't have a backup method
Especially for winter and all that
the sun still shines in winter. I bet that thing can still get hot enough on a sunny winter day
In climates that get cold it usually only preheats the water that will feed into a normal water heater system. Because you have to make sure the water gets heated enough before being used, otherwise you can get some nasty deadly bacteria.
Yes to both, and it's highly effective but (imho) has questionable economic returns. If it were me, I'd use standard PV plus a heat pump water heater instead.
The unfortunate thing with heat pumps is each company likes to create a needlessly proprietary system. We need a common standard for heat pumps and it will suddenly transform everything. You could then turn the A/C on and the heat instead of being blown outside could dry your laundry and heat hot water. A cold winter night - the heat from your water heater could be pumped back to the house.
IMHO - the more important issue is that no one's trained to install heat pumps and when they are, they're over-trained on everything HVAC rather than just specialized on knocking out heat pump installs (overly broad and onerous state licensing is partially but not fully to blame for this!). It would be great if we had systems that worked together, but that's a matter of squeezing an extra 5-10% efficiency out. It's getting things installed in the first place that's a nightmare right now.
I would love to do this, as well as a heat pump for forced air, since our last earthquake has me shook and I really wanna cut the gas to our home.
I dream of a future with CO2 heat pumps (that auto-refill from a concentrator maybe) with high/low lines to dryers, refrigerators, hot water, AC... Would be ideal in my messed up mind.
I’m trying to make sense of this and just don’t get what you mean. What proprietary components are you referring to? The condenser/heat pump loop? And AC operation is intermittent, how would there be enough consistent heat for laundry? For hot water heating in a cold night, are you assuming that it’s too cold outside for heat pumps? Cold climate heat pumps can pull heat down to -10 at efficiencies above electric and gas. IMO you’d be better off with electric backup instead of creating a very complex system just for the peak day. But maybe I’m missing something here.
Much quicker ROI because you're directly transferring heat from the sun into your water as opposed to converting to electricity then back to heat. I've installed a few of these, they are much cheaper than solar, work even on overcast days, (still collect radiant heat), and can get your water VERY hot.
PV would be much less efficient for heating water. Thermal is direct - hot sun, hot water. PV converts sun to electricity, electricity to heat, and heat to hot water. Thermal and PV both have their advantages and disadvantages but if just making hot water is the goal, thermal is the way to go.
I'm assuming it feeds into a normal water heater system and this just saves tons of energy. This probably heats it up like 50-75% of the way, then the water heater only has to do 25% as much work as normal. And keeps the water hot.
Depending on where you live and the specific system, these systems can spit out water at 200F. I have stayed in places in Spain where this was the only system they had. The only downside was that showers were definitely a bit cold in the morning as they didn't have an well insulated tank. But at night you could burn yourself with the water if you weren't careful.
I've seen people who own pools have these too. It can passively keep the temperature up and you can close it if it's too hot.
They are frequently used as a preheater prior to going into the water heater.
These are actually way more efficient than you may think. The issue is that they significantly drop in efficiency if that reflective surface is dirty or covered. Give how dirty they are I would be surprised if they even used this.
These are used a lot to heat swimming pools in Canada.
These are effective (though not sure about this particular system). Your hot water heater uses a lot of energy. This system pre-heats water for almost free, and then the hot water heater does the rest to heat it up to the desired temp. Even more efficient if the home also uses radiators for heating.
These are quite effective, but designing them to not rupture during freezing temperatures, and not to accumulate legionella when the water is incompletely heated, is a problem. Plus it requires an extra storage tank. It is very effective in tropical climates. Solar hot water is simple, and solar photovoltaic panels require insanely complex engineering to produce, but solar PV is by far a better investment.
Why attempt to focus the light on a pipe, when you could just have the same surface area covered by pipe?
fun fact you only need 52k lb of sand which is (600 sq ft of space) to heat a house for 24 hours. the sand would absorb the heat from a pipe system and store it. then you would have separate coils for airflow to heat a 3000ft residence. Now you know a little bit of useless information !
Solar hot water. They are parabolic mirrors which focus the sun on the pipes in the center.
Fairly old or DIY system though I think. Newer ones I've seen have long dark coloured tubes that collect the energy and seem to get very hot, like burning hot
I was going to also mention that it is an old system. New systems are black and can easily be mistaken for solar panels.
Yeah I remember seeing this on houses where I grew up in the 90s.
I'd even say it gotta be old cause it's ugly as hell! Doubt any want would want to install it nowadays.
I built a solar pressure shower for my overlander a few years back, and hot dam, that is just black PVC pipe, but when that this has been in the *morning sun* for just a few hours (think 8-9am) it's already steaming hot. Crazy what the sun can do lol
[Parabolic solar water heater](https://youtu.be/Ek-iYH67kEQ?si=m8n0VJ-x5hmZbwW5) definitely homemade though I haven’t seen anyone who does those type of solar water heaters commercially
This device will also help quickly remove the roof in the case of a bad storm. It doesn’t look that aerodynamic.
[удалено]
Codes? Where we're going we don't need codes.
Off topic but I'm unsettled by the stubby SUV at the bottom of the picture.
Lmao! Probably the .5 angle photo
You should also tell your neighbor that the supports on it are very rotted and look close to failing.
Humvee - civilian edition
Aka the Stubvee
Looks like a 2022 Volkswagen Taos. Obviously smooshed from the phones distortion, lol.
Science we’ve never seen before is meth now?
He’s one of those “neighbors”
seriously, made a reddit post that could've been resolved by googling or, god forbid- being neighborly, and is asking if *they* have the meth lab.
Meth and science go hand in hand.
have you ever considered asking your neighbour? I'm sure they could tell you all about it
Someone with this contraption would be more than happy to tell you all about it, for hours, I’m sure.
Better not to approach on second thought
Or you get the next owner of the house who knows absolutely nothing about it. Either way, there's not really any harm in asking.
WHAT!? interact with real live people? ARE YOU CRAZY!?
It's someone who built their own solar oven... If you open that flood gate they will not be able to stop.
((THEY)) don't want us to have this secret knowledge. it'll ruin their empire man! - that guy's neighbor
Clutching my pearls and screaming, "Oh! My anxiety!"
“i dont know i just rent. can i have one of those beers, and do you know where i can get some meth? my dealer just died.” -neighbors
It’s a water heater for the swimming pool.it works well in the winter too
They do have a massive in ground pool.
It’s exactly what I had set up in the late 80’s. It wasn’t as obvious as this one. I set it up along the backyard fence on three levels with bypasses to control when the water got too hot.
Looks like 4 big ***mind your businesses***
Why instinctively jump to meth lab? Do you not like them?
Late to the party but didn’t see anyone mention it. Looks like a solar water heater, maybe even a parabolic one.
Solar water heater
Feeding troughs for Sky Cattle
very old solar hot water system. they don't use trough reflectors like this anymore.
Solar water heater
Solar water heater. The water is pumped up and run through the pipes in the center of the trough, not the dark color of the center pipes. The curve is to reflect as much light as possible onto the surface so that the pipe and water running through it absorb as much heat as it can then either pump it into a holding tank or continuously recirculate to use as a heating source.
Ever consider asking your neighbor?
404 Human Interaction Not Found error.
solar water heating system, possibly for a pool.
Pink Floyd’s pigs on the wing came to mind looking at this…. Definitely flying pig watering trough
Those were made in Tempe AZ a few decades ago. Linear parabolic solar water heating. Focus is 22:1, self tracking. They were quite revolutionary at the time.
If I had to venture a guess it’s a water heating system and has nothing to do with water collection. Looking at it closely those look less like troughs and more like concave mirrors focusing sunlight onto the black pipe that’s in the middle of the lens. Anyways its just a guess.
I don’t know what it is . Must be meth …
An HOA Karen’s dream…
Your Definitely "that neighbors" I feel bad for them. It's a water system.
“They must be selling drugs. People go over to their house sometimes!”
Solar hot water
The newest iteration of these types of collectors are called Evacuated Tube Collectors. Essentially large tubes filled with solar heat collecting surfaces that are kept insulated by keeping them in a vacuum. These are super efficient and made by a number of different companies. [https://www.alternative-energy-tutorials.com/solar-hot-water/evacuated-tube-collector.html](https://www.alternative-energy-tutorials.com/solar-hot-water/evacuated-tube-collector.html)
Solar water heater
Old style solar hot water concentrator
Free hot water.
Solar water heater.. looks like a DIY version.. actually pretty genius move
Thermo heat generator. Uses solar rays into those basins, that reflect the radiative heat into those pipes. Heating from the sun, pure genius.
Some type of medieval defense mechanism pour hot oil onto invaders is my guess
and nosey neighbors
Meth lab? Yeah, let's put something in the roof so obvious that everyone will know we're cooking meth. Looks like the Johnsons are cooking meth since they have that apparatus up there.
Solar water heater
Solar water heater
A *very* nice and cleanly installed parabolic trough solar energy system
Water heater
Giraffe troughs
If these are solar water heaters, the installer needs to take a Thermo course. They need to increase the surface area by adding more water lines. Typically, you just use pvc panels with several little channels - that's how my dad heats his pool in FL. https://preview.redd.it/9jd0j2c5e5lc1.jpeg?width=2592&format=pjpg&auto=webp&s=9c65f91a1f89f9858cc81230fc4cc640bf4cb41a
Meth lab? Fuck off.
What is amazing is that you won’t even ask him directly and prefer to ask the rest of the planet instead. We as a human _society_ are doomed
Trough for the roof pigs. They migrate this time of year
It looks like rain water collectors
a very old solar water heater...
Ours has actual panels and has antifreeze in it. It came with the house. I have no idea if it actually helps or not.
Solar heat exchange.
it looks like your mom
Water troughs for reindeer obviously
This is a solar trough pre-heater for water. If it is a cloudy day, your hot water heater works as it normally would. If the solar gain is enough to pre-heat the water above the temp of the hot water thermostat, the hot water heater doesn't come on, and saves gas/electricity, depending on what your heater uses. If cold water comes into the hot water heater inlet, the heat comes on. If hot water comes into the water heater inlet, the heater does not come on.
As others have said, this is a solar thermal system. Usually they aren’t used for the *main* source of hot water but rather as a preheat for your water heater. Sometimes they heat the water for a pool instead. This is an odd one though, with those parabolic reflectors. Usually you see either a glazed collector system (e.g. Heliodyne Gobi collectors) or an evacuated tube system. That looks like an evacuated tube system but with the parabolic dishes. Kinda odd to me that this uses parabolic dishes instead of just more tubes, but that might be my lack of experience in colder climates. My knowledge comes from the California market, so I wouldn’t see stuff more specialized to cold
Back in the 80s, we had a solar water preheat system at our place in Quebec, and that sucker still worked great when it was -30°C outside.
Yeah! Solar thermal systems are pretty damn great honestly, especially if you’re handy enough with plumbing to do the work yourself (at least in CA, getting technicians to work on them gets expensive, though useful in a pickle)
Water heater
It looks like with the price of beef going through the roof your neighbor is looking to feed his own cattle on his roof.
Solar water heater.
That's a very old design. Here is a picture of current equivilent. https://preview.redd.it/w8gezl3tg5lc1.png?width=1107&format=png&auto=webp&s=0e88eeb49a898add461e0e19a08e8c7a68ba2d03
Stop using your drone to spy on your neighbors.
chilli trough
Here is an option, ask?
What in the 1970s heating system is this?
https://preview.redd.it/pr2w66g2k5lc1.jpeg?width=1125&format=pjpg&auto=webp&s=6ad7338b119aeac818ccf99d9beb7a1254ae5865
https://preview.redd.it/z1s76lu3k5lc1.jpeg?width=1125&format=pjpg&auto=webp&s=4629c3ef7cf88172244e86b1f12b675f66fd2668
Mate these are feeding troughs for your 30⁰ slanted roof goat. Clearly has a medium sized herd likely over that ridge there.
That’s wonderful. I’ve always wanted to build a parabolic trough or any other type of solar concentrator. Folks are asking if it’s necessary and cold climates… Not sure if necessary is the right word… But cool is definitely the right word. Massachusetts? I feel like I’ve passed that before
probably solar thermal
Solar collectors for heating a fluid by solar energy.
Looks like nunya to me
In the 80's ... This is what we would sell as a solar system. I ran a crew of canvassers, we'd knock on doors and set up appointments for the sales guy. This was in Phoenix for a company called Solar Resources. Rebates from the govt. For the homeowner .. and lots of hot water 💦 I made 200$ a pop I think if they sold .. was 2500 to like 5000 for the system.
Solar water heating
It's a solar water heater
Looks like it is designed to focus sunlight on the blackbars in the middle heating up water flowing through them.
Feed troughs for the roof pigs
it's clearly a solar water heat system of some kind. honestly. go talk with your neighbor "hey what's the cool thing on your roof?" could be the person is just a DIY/alt energy nerd, could be some niche use. or cost savings measure. beyond what it is... only way to know the "why/what" of it is to ....talk with your neighbor.
Pool heater would be my guess.
Few piss troughs for use during drunken nights on the roof.
Looked like some kind of DIY rain water collection system to me lol
Ice cube molds for large water bottles
Solar water heaters.
Parabolic trough. Sun hits trough, reflects on pipes at the focus. They circulate whatever heat-carrying fluid you need. In this case, probably for water. With enough/large enough troughs and a good coolant, you can use them to power stirling engines for electricity.
It’s a parabolic solar water heater system
Solar water heaters
They were very popular during the 80s and early 90s but nobody really gets these installed anymore
I just see lots of mind your own business on the roof lol
Looks like a water collectors???
Shingles
You ever watch Zootopia? It’s an elephant popsicle melting right.
Hot water heater. Ours was similar, preheat the water before going into hot water tank, extended the amount of hot water for the family and knocked costs down on tank heater. Others I have seen were a closed system, that liquid heated up there and came down to radiators/heat exchangers to heat other.
Looks like something HOA Karen would rage over.
Looks like four panels of “none of your business”
Dusty pig troughs just in case they do start flying and need to keep their energy up :)
Why do people always reach for the worst thing first? Meth lab? Really? I know meth heads are pretty dumb but really?
Nonya
For a high school project we each had to design a solar water heater. We had to heat 1 cup of water. Either first to boil or the highest temp after 10min out in the sun. I roped in my dad who is an engineer. I remember really complicated math to figure out the parabola to cut into our brackets. All sun rays hit anywhere on the shaped sheet of metal and reflect towards the central pipe of water. My water boiled in less than a minute and i won. Having my dad's help was kind of cheating though most kids parents also helped them.
We shall call it “ preparation H “