> I don't know why so many use the salt
salt only works within a specific temperature range. it can be too cold and be beyond its capabilities, in that case grip from sand or gravel is preferred.
Because winter is 6 months where I live (Canada) and people have places to be. People have winter tires for their bikes.
First snow is in October/November, snows finishes melting late April. So yeah.
and if you have tires to handle snow.. you have tires to handle sand. Though as another commenter pointed out, the sand stays after the snow is gone, which is a different issue.
despite what people think, it doesn't always snow during the winter where everyone lives. I bike daily because it snowed twice in my city this year due to average winter temps of high 30's. You can definitely bike through snow too, but ice is awful though
We don't have much for heated sidewalks where I am (western Canada), or really much road salt. Just sand or gravel and shoveling. Part of it is that the cities are very spread out and flat, but the lack of salt is just because it's too cold out to work most of the time in Nov-Feb. Saskatoon/Regina/Edmonton are significantly colder than Helsinki, more like the very northern tip of Finland.
The Calgary zoo redid their main entry plaza about 15 years ago and put in pavement heat. The salt savings (and reduced environmental harm) and the increased longevity of the concrete far outweigh the energy costs.
I used to live in Saskatoon and can confirm. There's little to no salt on the roads as salt runoff is devastating to the local agricultural industry, and the fact that they don't work in -25C.
my last post in this sub had everyone concerned about the environmental impact of heated sidewalks, so i thought i would share a picture of them working as intended.
i work at a hospital, so this helps prevent injury and saves a ton of labor. the heated portion of sidewalk extends around about half the building, prioritizing areas where patients will be walking the most.
A city I used to live in has a very rich heritage in the waterways it's built on. Right now there's an ecological disaster happening with road salt and farming runoff changing the makeup of the lakes, creating algal blooms and killing everything. Conversation on the topic is divided, with a large faction contributing commentary to the effect of, "It's a modern society, we need to get to work, nothing can be practicably changed and resistance is futile."
I understand heating every square foot of concrete in a city is genuinely unattainable, but it still makes me feel sad as hell to look at it lol
Eutrophication, the effect of fertilizers entering into lakes and streams and accelerating algal growth isn’t just a conservation issue—it’s a health and property value issue! Those algae blooms can be hazardous the breathe around, as people in my home state can attest. There have been some massive blue algae blooms in Milford lake that have actually interrupted operations on Fort Riley. And if you have waterfront property on a nice clean lake or stream, you’ll see your property values drop considerably when the fish are dead and rotting and there’s a nasty sludge covering the top of the water. So if someone doesn’t care about collapsing ecosystems, they’ll definitely care about property values.
PNW checking in.
We occasionally get "don't let your dog drink from the river or it might die" advisories for algae. Half the reason people hike on all the trails going up and down the river is the access to the water.
I live in NJ and the State has made great strides to alleviate flooding concerns due to stormwater, as well as provide buffers for waterways and the like. Farming, unfortunately, need not apply. And I get it, farming is important, but where one development would need 150 or greater feet of separation from watercourses, farmers can apply pesticides and herbicides up to 35 feet from those same watercourses. And not to mention the water usage. I don't pretend to have a solution for the amount of water used, but I think limiting the area of a farm to buffers equal to those of any other use only seems fair. It's all just the bottom line, and so if Johnny Warehouse or Suzie Residential Development need 150-foot buffers, and accept the financial consequence for adhering to them, I don't see why Old MacDonald does not as well.
I like rivers, big fan. Such an amazing resource, and hopefully NJ, and to a greater extent the rest of the country, can do better protecting them.
There are solutions to the water, too. They're just more expensive than those giant fuck wheeled water sprayers that piss away thousands of gallons of water.
Similar thing here in Iceland. We have some of the worst air pollution in Europe because of studded tires which tear up the asphalt into nice fine breathable particle so exercizing in winter makes your lungs burn that extra bit
There was even a preschool which cancelled outdoor recess because the pollution that day was so bad
I think the use of liquid salt in Finland significantly reduces the amount of salt needed, however it's more expensive and must be done in the appropriate temperature range.
That's mainly what I see them use on the highways in Ontario now, that brine stuff gets sprayed. The salt/sand mix is effective however at improving traction on plowed but icy secondary roads.
I wish. Right now there are only limits on salt use. Every time it snows, local forums are filled with posts about the danger and lost economic activity, demanding that the limits be lifted. In practice, it is a complicated conversation which can reasonably sprawl out into discussions on the effectiveness of local and state government or the welfare of various demographics.
And we have failed and are failing to stop this damage from happening despite what we have done, which makes a lot of people more nihilistic about it and makes it difficult to move the conversation forward. I'm hoping for the best and expecting the worst ha
Runoff from new development is shutting down more and more shellfish areas in Murrells Inlet, SC. My favorite beds for picking clams are now permanently closed. That leads people to pick from the remaining beds. I used to be able to dig a bushel in 30 minutes. The last time I went out, my brother and I together only got half a bushel before the tide came back in.
For sure, it's a shame what we're doing to waterways.
Like yes, I agree that human health and happiness is more important than biodiversity...but we're so *wasteful* about it. We can do a much better job achieving both.
> "It's a modern society, we need to get to work, nothing can be practicably changed and resistance is futile."
My Conservative father's favorite line "No one wants to consider the economic impact!"
Monoculture lawns and golf courses are pretty useless and we can easily get by without them. They cause excessive harm with marginal benefit. And we need more gmo crops and computer analysis for fertilizing to increase yield rather than more fertilizer. After all runoff means wasted fertilizer.
This is a HUGE problem in Maryland currently as the Chesapeake bay gets runoff not only from MD but from several other states as well and unfortunately any actions taken by MD itself will only have limited effect unless the neighboring states all enact identical measures.
Is calcium chloride your standard road salt where you live? Here, sodium chloride is the norm, but for concrete surfaces or lower temperatures, magnesium chloride is preferred. Calcium chloride, while available and marketed as road salt and with similar advantages as magnesium chloride, is often considered too expensive.
Also, some places simply have "waste heat" that was gonna get exhausted anyway. Some big power plants run their waste heat under the sidewalk of the community to the delight of everybody in the winter.
I've seen pics from one of my former belarus co workers of soviet era housing blocks, the central water boiler distributes hot water to the surrounding buildings, and you can tell where the large pipes are underground since that's where there is no snow. (I don't think there were sidewalks tho)
Only to a certain temperature. In the town I live in the district heating is heated by the steel plant but the district heating system only works to a certain temperature so the rest of the now "lukewarm" water is used to heat sidewalks and also a small lake close to the steel plant that stays ice free year around. District heating
I think a lot of folks see these and think, wow, must be expensive to keep the sidewalks hot.
But in reality, you just need to keep them a bit above 0C/32F. So they are still cold, but the snow doesn't stick when it lands. It melts away.
These side walks are still cold. Just not freezing cold.
I mean this is exactly like that... I put a driveway loop in my new radiant floor system that I can turn on and off with a smart switch. Loops 1-3 heat the building loop 4 melts snow. Personally I still plow and then turn it on as an alternative to salt since I have a lot of marshes and wetlands adjacent to my driveway.
It's like how it can snow all day but you don't have any snow accumulation.
Snow won't accumulate until the ground itself is below freezing, which takes a very long time. Until then, the snow will hit the ground and melt, and a snow flake isn't much of a cooling agent.
Instead, we look at the times when the ground manages to cool below freezing and we have hours of snow buildup. We look at the giant pile of snow and think "That would take a lot of heat to melt". But in reality, if your melting each snowdrop as it falls, you need almost no heat.
>Until then, the snow will hit the ground and melt, and a snow flake isn't much of a cooling agent.
Phase changes take a lot of energy, so, I disagree with this: a snow flake is a great cooling agent. It takes the sidewalk the same amount of energy to melt a snowflake as it would to raise an equal weight of water by 83 degrees Celsius.
See my [other comment](https://www.reddit.com/r/mildlyinteresting/s/dMB7FHdvU2) for the math. The energy required to melt a kilogram of snow is the same regardless of how quickly or slowly you do it.
https://www.youtube.com/watch?v=vAyPBe2wMFg is a great dive into the complexity of snow removal and calling out that heated sidewalks / roads are actually the most environmentally friendly approach to snow removal.
That’s what I figured. I think a lot of people here are imagining them running 24/7 at super high temps. When in reality, it’s probably only turned on a handful of times a year and only for a few hours [edit: and at low temps as people have pointed out]
If they work anything like my heated floor at home (probably not) it stays at about 30-35C to have 18-20° inside when it's around 0° outside.
These don't need to warm up the area, so they are probably just warm enough to go above the 3°C level where snow can start building up on the ground.
They don't even have to run at high temps. They just need to be warm enough to prevent snow accumulation. So the water running through them might be pretty hot but as long as the surface stays around 40F you won't get snow accumulation.
Most of these systems either have a simple on off to enable the loop or you can get smart sensors that detect snow or tie into forecasts and see if it is below freezing and there is precipitation.
The ones at my work have since broken but it used to just be a switch.
EDIT: I want to add that the switches were a breaker panel. I'd be super surprised if any system didn't have a breaker panel that you could turn off during warmer weather.
The warehouse I worked in had heated floors...but the thermostat broke, and was too "expensive" to repair, so they were an "all the way on, or completely off" deal. Our feet ROASTED all winter, to the point where it was painful.
They can be manual, but most likely have at least a temp sensor embedded in the slab. The slab only needs to be a few degrees above freezing to prevent snow and ice. Some systems also use sensors that can detect falling snow or ice.
You can achieve this in a few ways some would be "always on" and others are controlled.
My college put air conditioners, heaters, water heaters, etc. underground next to sidewalks so the thermal exhaust would naturally melt the snow. That was technically "always on" but was using no additional energy.
One of the "on/off" versions works by putting metallic flakes and then adding a very low electrical current. As the electricity jumps from flake to flake it creates heat.
Many of these systems are thermometer driven and turn on when extended temps at or below 34-35F are measured.
They cycle on/off as needed to keep the sidewalk temperature around 33 degrees.
The electrical circuit will also typically have a Ground Fault Circuit Interrupt to prevent electrocution hazard if the cable powering it gets nicked or damaged.
I think people don't really have a good handle on what *really* causes problems. They see something like this and believe it's hugely wasteful. Same deal with single-use plastics for things like medical lab work, for example.
Like, it's *okay* to do the super expensive things in key areas where it's most beneficial. The problem isn't a little plastic in our waterways, it's having plastics be for everything that everybody uses at industrial and consumer levels.
Heating key sidewalks where large numbers of physically impaired and/or frail people are walking? That's perfectly reasonable.
Compared to the salt and labor of conventional snow-clearing, which does a less thorough job, heated sidewalks are fantastic.
I've worked with a system like this before. Ours worked based on moisture detectors embedded in the concrete, along with information about the outdoor air temperature. If the ground is wet and it's freezing outside, the system would engage. It isn't wasting energy on days that are only cold or wet.
Although it uses energy to melt the snow, it uses the worst, most useless heat the building produces. Because it only needs to be barely above freezing, it can use whatever heat is left over after the boilers have heated the building. This means there isn't a dedicated boiler for this system that only works a few days a year, or even a larger boiler required for the building overall. Instead there would be a heat exchanger and a smaller local pump to run this system only as needed.
Question about this, how is the ice build up around the heated area? Thats always been a concern of mine for doing something similar for a driveway and the like. I'd hate to have the run off water freeze into pour conditions for anyone walking by.
>i work at a hospital,
Explanation complete. No need to justify further why the sick and injured could use a non-icy walkway.
I mean, good idea in lots of places, but I have vivid memories of having to go out and salt/shovel the walkway at the clinic I worked so patients would stop seemingly aiming for the iciest route possible.
It's no wonder we've developed such great BBQ down here. Every summer our George Foreman sidewalks flip on for 5 months of uninterrupted free use to anybody and everybody with something to sear.
Worker’s Compensation Professional here (certified) and I can confirm Slips/Trips/Falls are the #2 cause of injury and by far the most costly on the employer and painful for the emoloyee. #1 is ergonomic issues and that would include back injuries from shoveling or lifting snow. This is a great idea and it could (and likely will) literally save lives
Bonus points for being a hospital where far fewer liability issues that aren't workers are going to arise due to undissolved ice melt, unmelted ice, or snow/ice that was not removed due to the aforementioned injured workers.
This is a great and perfect place for heated sidewalks. In fact, I would fully support a federal grant for the least climate hostile way to do this at every hospital that gets snow at least once per year on average.
I can't remember where, but I distinctly remember reading about a city where the main downtown sidewalks were built just over top of the water pipes running water for the city. The water pipes needed to be heated during the harsh winters anyways, so the radiant heat which would normally be lost to the ground was used to warm the sidewalks.
I'm not sure about the efficiency of such a system, or how well it would actually prevent ice and snow on sidewalks. But a key talking point was the extremely easy access and repair of the pipes under the sidewalk.
Here's a similar example.
Video: https://vimeo.com/299474831
Article: https://www.mlive.com/business/west-michigan/2016/02/why_holland_spends_millions_to.html
This is a good application of heated sidewalks. High traffic area with sick and disabled people travelling. I used to work building custom homes and when you have heated driveways, sidewalks, garages, In floor heated basements, bathrooms, and laundry rooms for two people its a bit unethical
That's true in some applications. It is very rare to see baseboard heaters in my area in a new build anyway. I think the last time I saw one was for a garage. All forced air now.
I heard Baseboard heaters were pretty bad at heating, that’s the main reason we don’t see them anymore. Makes it hard to place furniture too since the part of the wall it’s on is taken up by the heater. Been a long time since I’ve seen them anyways.
Indoors it’s actually better to have heated floors than standard. Regular floors will bleed your heat into your crawlspace that needs to be recouped by space heating, using a heated floor means you can recoup that lost heat with less energy than what would be needed via space heating, and your feet aren’t freezing. It’s essentially topping off a leaking jug with a small trickle rather than a constant stream.
I’m an energy science major and it took awhile for me to wrap my head around the idea. Anything outdoor for individual use is a bit wasteful though imo. This really is a perfect application.
I've done design work on fire stations and we would often put in slab heating for the apparatus bays that extend out past the bay doors to help keep snow and ice off the driving surfaces.
We already need to provide some form of heat for the bays, so extending the heating loops out further can reduce man hours of labor and provide additional safety for emergency vehicles.
Depends on how much it snows. Google says having the driveway run is like a 50W bulb every square inch. But it isn't on 24/7, just for the snowfall hours.
Heated garages don't have to be wasteful assuming they are well insulated.
Obviously, the bigger the house for two people, the more wasteful it is in general.
I want to do this for my parents ... but the systems I've found are expensive, about $250 for 6 feet. I wonder how much electricity this uses as well. Great for businesses, institutions, and municipalities... maybe out of reach for many home owners.
These are typically heated with propane or gas fired boilers. But they do get expensive to operate either way. A driveway about 40’ long for a 2 car driveway could cost as much to operate as the heating for the house for a season. This can vary quite a bit depending on how much snow there is.
Wow, that's more energy than I'd expect. You try to keep your house 70F +/-, I'd imagine you only need to keep the sidewalk above freezing so 35F would likely be fine, right?
I'd think this would be far less energy than that needed to heat a home.
It's the rate of cooling from an uninsulated surface, as you describe, PLUS the phase change from snow to water is a lot more energy intensive than people realize.
That said, there's no need to be running these off of propane or the electric grid. A heat pump/transfer system could be used to disperse the cold deeper underground, or even to outside/surrounding air*.
*I am not an engineer. I just don't see why not.
I looked into it years ago. A man installed a wood fired boiler. He had to start feeding it the day before the forecasted snow. Then for it to keep up with the snow, it was steady feeding the fire box for the boiler to keep up during the snow fall. He figured he'd burn enough wood to warm his home for a week everytime it was a significant dump.
> You try to keep your house 70F +/-, I'd imagine you only need to keep the sidewalk above freezing so 35F would likely be fine, right?
same amount of energy! heating water from 32->70 == heating ice from 32 to water 32
Glycol loop is super old school, modern method is multiple electrical resistant loops - reduces peak energy demand by heating in sections only as necessary.
I looked into some melters for my deck and stairs. The cost to run wasn't bad because they only had to be a little warmer than freezing to work. They only need to be on during snow accumulation times, not 24/7, so the electricity costs aren't too bad. But ultimately, I didn't make the purchase and with this year's very dry weather, it was a good move.
Hello fellow northerner
This winter was honestly godsend for me (was living in my car) but man, with how warm this winter was and the sudden snow dump, it's crazy people don't believe in global warming
Many years ago the university my folks work at was trying to recruit a new Chancellor. The job comes with use of this gorgeous historic Chancellor's house on campus. Well for this asshole it wasn't good enough, and they demanded the University build them a brand new house in the fanciest part down, and specified that it had to have heated sidewalks and driveways, even though we rarely get more than a few days of snow a year.
We'll ofc that year we had a big snowfall. And I don't know how, but a number of local homeless found her heated driveway and setup camp there. 😂😂
This also has the advantage that it prevents the water from turning into ice. Eventually with salt the water freezes flat and leaving it unsalted would have been safer. So you end up needing to keep adding salt till it dries. I live in Canada and people new to the winter season from warmer countries make this mistake. Throw salt down after shovelling while the snow is still falling, go to bed and wake up to snow covered ice the next day.
Hence the Monty Python quote…. Brain injury, body went into ANS shutdown. Breathing, nope. Heart - fibrillation. Pain oh so much damn pain. Ended up in a coma with machinery keeping me running until the bleeding in my brain stopped.
r/TBI can explain it, but it sucks.
Wear a damn helmet !
My parents put in a heated driveway a few years ago and they got a ton of push back from people saying it was an unnecessary expense it cost them about $28k but they constantly talk about how it was worth every cent
We have these at the urgent care clinics I do HVAC for! Overall, these aren’t terrible for the environment, as at least on our sites with heated sidewalks we use solar power which greatly cuts down on the environmental costs of heating the sidewalks. They also allow the sidewalks to last longer, so less concrete and construction materials used over the lifespan of the sidewalks, they are safer and they dont use road salt which is terrible for the environment. Thanks to the glycol in the water the system doesn’t need to run at more than probably 50-55 degrees, so its not like we are dumping 120 degree water outside.
I wonder why this combination isn't more common. Sidewalk that doesn't get enough sun to melt ice + solar hot water from elsewhere seems like it would be a winning combination.
A big thing is cost of installation and the remodeling that needs to be done in order to achieve this. It is a big upfront cost to install these systems and honestly most building owners dont care enough to pay for them. Unless they are already redoing the entire HVAC system, it isn’t cost effective to change out the building piping, boiler, and existing pumps to accommodate the glycol necessary to make these systems work. If you are building a new building this becomes a lot more feasible, but again, all of that depends on whether it is “owner occupied” or if it’s being rented (that, and, do you trust the tenants to upkeep the boiler system properly). I still love them though and I think this type of design is where we are heading in the future of construction, generally.
Had a boss from Austin buy a vacation home in Utah. The place in Utah had a heated driveway. He wasn’t one for details…turned it on…left it on…the electric bill was his first clue.
They're not electric, it's typically a heated glycol solution (read: antifreeze) run through flexible PEX pipe. It's tied down to metal mesh in an organized manner and they pour concrete on it though, yes.
My college tried this, but half-assed it.
In the winter when it snowed, the sidewalks turned into sheet ice. You could always tell who were freshman because they were walking (and slipping) on the sidewalks instead of walking in the snow next to it.
What blew my mind in Japan in the winter is - they have enough hot springs that they pipe hot spring water to bubble up on to the roads and melt snow. Very elegant and probably low carbon way of keeping the roads clear with geothermal.
I remember someone was looking at using Fatty Acid Methyl Esters to cause the concrete to heat up to like...34F once it got snow on it so that it'd melt itself.
How warm is it to touch? Still cold feeling but enough to melt ice, warm, hottt?
I imagine its most cost effective / energy efficient to warm juuuuust enough to melt things and keep ice at bay, but that doesnt mean they did it that way and idk how the system might determine how warm it needs to be to do the job so maybe it just has a single setting, maybe not.
But yea - have you touched it with your bare hand for science yet OP?
[удалено]
> I don't know why so many use the salt salt only works within a specific temperature range. it can be too cold and be beyond its capabilities, in that case grip from sand or gravel is preferred.
And sand on bare pavement can actually cause loss of traction… ask anyone who’s ridden a bike/motorcycle.
snow is the same thing, but worse, why would anyone be riding during the winter?
Because winter is 6 months where I live (Canada) and people have places to be. People have winter tires for their bikes. First snow is in October/November, snows finishes melting late April. So yeah.
Fat tire bikes with studded tires are a thing now. Reasonably popular here in Alaska actually.
and if you have tires to handle snow.. you have tires to handle sand. Though as another commenter pointed out, the sand stays after the snow is gone, which is a different issue.
despite what people think, it doesn't always snow during the winter where everyone lives. I bike daily because it snowed twice in my city this year due to average winter temps of high 30's. You can definitely bike through snow too, but ice is awful though
People still have to get to work
We don't have much for heated sidewalks where I am (western Canada), or really much road salt. Just sand or gravel and shoveling. Part of it is that the cities are very spread out and flat, but the lack of salt is just because it's too cold out to work most of the time in Nov-Feb. Saskatoon/Regina/Edmonton are significantly colder than Helsinki, more like the very northern tip of Finland.
The Calgary zoo redid their main entry plaza about 15 years ago and put in pavement heat. The salt savings (and reduced environmental harm) and the increased longevity of the concrete far outweigh the energy costs.
Calgary is an anomaly for this area, as their proximity to a pass through the Rockies gives them a much warmer climate than the rest of the prairies.
I used to live in Saskatoon and can confirm. There's little to no salt on the roads as salt runoff is devastating to the local agricultural industry, and the fact that they don't work in -25C.
my last post in this sub had everyone concerned about the environmental impact of heated sidewalks, so i thought i would share a picture of them working as intended. i work at a hospital, so this helps prevent injury and saves a ton of labor. the heated portion of sidewalk extends around about half the building, prioritizing areas where patients will be walking the most.
They also reduce the use of calcium chloride (road salt), which will inevitably melt into the local waterways. That stuff can be really nasty.
A city I used to live in has a very rich heritage in the waterways it's built on. Right now there's an ecological disaster happening with road salt and farming runoff changing the makeup of the lakes, creating algal blooms and killing everything. Conversation on the topic is divided, with a large faction contributing commentary to the effect of, "It's a modern society, we need to get to work, nothing can be practicably changed and resistance is futile." I understand heating every square foot of concrete in a city is genuinely unattainable, but it still makes me feel sad as hell to look at it lol
Eutrophication, the effect of fertilizers entering into lakes and streams and accelerating algal growth isn’t just a conservation issue—it’s a health and property value issue! Those algae blooms can be hazardous the breathe around, as people in my home state can attest. There have been some massive blue algae blooms in Milford lake that have actually interrupted operations on Fort Riley. And if you have waterfront property on a nice clean lake or stream, you’ll see your property values drop considerably when the fish are dead and rotting and there’s a nasty sludge covering the top of the water. So if someone doesn’t care about collapsing ecosystems, they’ll definitely care about property values.
PNW checking in. We occasionally get "don't let your dog drink from the river or it might die" advisories for algae. Half the reason people hike on all the trails going up and down the river is the access to the water.
I live in NJ and the State has made great strides to alleviate flooding concerns due to stormwater, as well as provide buffers for waterways and the like. Farming, unfortunately, need not apply. And I get it, farming is important, but where one development would need 150 or greater feet of separation from watercourses, farmers can apply pesticides and herbicides up to 35 feet from those same watercourses. And not to mention the water usage. I don't pretend to have a solution for the amount of water used, but I think limiting the area of a farm to buffers equal to those of any other use only seems fair. It's all just the bottom line, and so if Johnny Warehouse or Suzie Residential Development need 150-foot buffers, and accept the financial consequence for adhering to them, I don't see why Old MacDonald does not as well. I like rivers, big fan. Such an amazing resource, and hopefully NJ, and to a greater extent the rest of the country, can do better protecting them.
There are solutions to the water, too. They're just more expensive than those giant fuck wheeled water sprayers that piss away thousands of gallons of water.
Great way to get conservatives to actually support conservation is to tell them their property values may go down. That's their primary concern.
[deleted]
Similar thing here in Iceland. We have some of the worst air pollution in Europe because of studded tires which tear up the asphalt into nice fine breathable particle so exercizing in winter makes your lungs burn that extra bit There was even a preschool which cancelled outdoor recess because the pollution that day was so bad
I think the use of liquid salt in Finland significantly reduces the amount of salt needed, however it's more expensive and must be done in the appropriate temperature range.
That's mainly what I see them use on the highways in Ontario now, that brine stuff gets sprayed. The salt/sand mix is effective however at improving traction on plowed but icy secondary roads.
Maybe they could copy the czech? Road salt is banned in the region where they make their beers to avoid contamination.
I wish. Right now there are only limits on salt use. Every time it snows, local forums are filled with posts about the danger and lost economic activity, demanding that the limits be lifted. In practice, it is a complicated conversation which can reasonably sprawl out into discussions on the effectiveness of local and state government or the welfare of various demographics. And we have failed and are failing to stop this damage from happening despite what we have done, which makes a lot of people more nihilistic about it and makes it difficult to move the conversation forward. I'm hoping for the best and expecting the worst ha
Reading this sounds a lot like Madison, WI
For sure. Lakes, plural. Scrolled down to see if anyone else had the same thought. They do get nasty sometimes.
Thought the same.
Runoff from new development is shutting down more and more shellfish areas in Murrells Inlet, SC. My favorite beds for picking clams are now permanently closed. That leads people to pick from the remaining beds. I used to be able to dig a bushel in 30 minutes. The last time I went out, my brother and I together only got half a bushel before the tide came back in.
For sure, it's a shame what we're doing to waterways. Like yes, I agree that human health and happiness is more important than biodiversity...but we're so *wasteful* about it. We can do a much better job achieving both.
It probably could if you use the proper types of heating, e.g. deep well geothermal.
> "It's a modern society, we need to get to work, nothing can be practicably changed and resistance is futile." My Conservative father's favorite line "No one wants to consider the economic impact!"
Monoculture lawns and golf courses are pretty useless and we can easily get by without them. They cause excessive harm with marginal benefit. And we need more gmo crops and computer analysis for fertilizing to increase yield rather than more fertilizer. After all runoff means wasted fertilizer.
TIL road salt is a different from table salt
Do NOT substitute Road Salt for Table Salt
[удалено]
Well, my gluttonous week of lentil+road salt soup is now ruined
I have used table salt in a pinch, though, where road salt wold otherwise have been applied.
Right... Just like you can play catch with an apple or a baseball, but you can't eat the baseball.
https://youtu.be/RJh9yTIBY48?si=o-pnSk3HiSFqx-at
Explosions and fire my beloved ❤️
I think the majority of road salt is mostly NaCl. Occasionally CaCl and other salts will be used for lower temps when NaCl salt water will freeze.
Correct. In some places MgCl2 is also used.
This is a HUGE problem in Maryland currently as the Chesapeake bay gets runoff not only from MD but from several other states as well and unfortunately any actions taken by MD itself will only have limited effect unless the neighboring states all enact identical measures.
Is calcium chloride your standard road salt where you live? Here, sodium chloride is the norm, but for concrete surfaces or lower temperatures, magnesium chloride is preferred. Calcium chloride, while available and marketed as road salt and with similar advantages as magnesium chloride, is often considered too expensive.
Also, some places simply have "waste heat" that was gonna get exhausted anyway. Some big power plants run their waste heat under the sidewalk of the community to the delight of everybody in the winter.
I've seen pics from one of my former belarus co workers of soviet era housing blocks, the central water boiler distributes hot water to the surrounding buildings, and you can tell where the large pipes are underground since that's where there is no snow. (I don't think there were sidewalks tho)
The waste heat can be used for district heating.
Only to a certain temperature. In the town I live in the district heating is heated by the steel plant but the district heating system only works to a certain temperature so the rest of the now "lukewarm" water is used to heat sidewalks and also a small lake close to the steel plant that stays ice free year around. District heating
I think a lot of folks see these and think, wow, must be expensive to keep the sidewalks hot. But in reality, you just need to keep them a bit above 0C/32F. So they are still cold, but the snow doesn't stick when it lands. It melts away. These side walks are still cold. Just not freezing cold.
I’d assume this is because folks’ first thought is probably radiant flooring seen in residential housing sometimes.
Which also isn’t that expensive to run… it’s a pretty green option if you can afford the install costs
I mean this is exactly like that... I put a driveway loop in my new radiant floor system that I can turn on and off with a smart switch. Loops 1-3 heat the building loop 4 melts snow. Personally I still plow and then turn it on as an alternative to salt since I have a lot of marshes and wetlands adjacent to my driveway.
It's like how it can snow all day but you don't have any snow accumulation. Snow won't accumulate until the ground itself is below freezing, which takes a very long time. Until then, the snow will hit the ground and melt, and a snow flake isn't much of a cooling agent. Instead, we look at the times when the ground manages to cool below freezing and we have hours of snow buildup. We look at the giant pile of snow and think "That would take a lot of heat to melt". But in reality, if your melting each snowdrop as it falls, you need almost no heat.
>Until then, the snow will hit the ground and melt, and a snow flake isn't much of a cooling agent. Phase changes take a lot of energy, so, I disagree with this: a snow flake is a great cooling agent. It takes the sidewalk the same amount of energy to melt a snowflake as it would to raise an equal weight of water by 83 degrees Celsius. See my [other comment](https://www.reddit.com/r/mildlyinteresting/s/dMB7FHdvU2) for the math. The energy required to melt a kilogram of snow is the same regardless of how quickly or slowly you do it.
https://www.youtube.com/watch?v=vAyPBe2wMFg is a great dive into the complexity of snow removal and calling out that heated sidewalks / roads are actually the most environmentally friendly approach to snow removal.
there are some very angry people in these comments that would love to disagree with you lol
Reddit is full of people that like to pretend they are better than others. They also seem to be experts in everything
Are they “always on” or is there like an on /off switch? Or is it automated?
i believe they just turn them on when slippery conditions are expected
That’s what I figured. I think a lot of people here are imagining them running 24/7 at super high temps. When in reality, it’s probably only turned on a handful of times a year and only for a few hours [edit: and at low temps as people have pointed out]
If they work anything like my heated floor at home (probably not) it stays at about 30-35C to have 18-20° inside when it's around 0° outside. These don't need to warm up the area, so they are probably just warm enough to go above the 3°C level where snow can start building up on the ground.
It's way cooler than that, as it just needs to melt snow. The one at my old school only heated the walkway up to about 15C.
They don't even have to run at high temps. They just need to be warm enough to prevent snow accumulation. So the water running through them might be pretty hot but as long as the surface stays around 40F you won't get snow accumulation.
Most of these systems either have a simple on off to enable the loop or you can get smart sensors that detect snow or tie into forecasts and see if it is below freezing and there is precipitation.
The ones at my work have since broken but it used to just be a switch. EDIT: I want to add that the switches were a breaker panel. I'd be super surprised if any system didn't have a breaker panel that you could turn off during warmer weather.
The warehouse I worked in had heated floors...but the thermostat broke, and was too "expensive" to repair, so they were an "all the way on, or completely off" deal. Our feet ROASTED all winter, to the point where it was painful.
They can be manual, but most likely have at least a temp sensor embedded in the slab. The slab only needs to be a few degrees above freezing to prevent snow and ice. Some systems also use sensors that can detect falling snow or ice.
You can achieve this in a few ways some would be "always on" and others are controlled. My college put air conditioners, heaters, water heaters, etc. underground next to sidewalks so the thermal exhaust would naturally melt the snow. That was technically "always on" but was using no additional energy. One of the "on/off" versions works by putting metallic flakes and then adding a very low electrical current. As the electricity jumps from flake to flake it creates heat.
Many of these systems are thermometer driven and turn on when extended temps at or below 34-35F are measured. They cycle on/off as needed to keep the sidewalk temperature around 33 degrees. The electrical circuit will also typically have a Ground Fault Circuit Interrupt to prevent electrocution hazard if the cable powering it gets nicked or damaged.
I think people don't really have a good handle on what *really* causes problems. They see something like this and believe it's hugely wasteful. Same deal with single-use plastics for things like medical lab work, for example. Like, it's *okay* to do the super expensive things in key areas where it's most beneficial. The problem isn't a little plastic in our waterways, it's having plastics be for everything that everybody uses at industrial and consumer levels. Heating key sidewalks where large numbers of physically impaired and/or frail people are walking? That's perfectly reasonable.
> environmental impact of heated sidewalks Probably less harmful than the f***ton of salt that would be spread here otherwise.
Compared to the salt and labor of conventional snow-clearing, which does a less thorough job, heated sidewalks are fantastic. I've worked with a system like this before. Ours worked based on moisture detectors embedded in the concrete, along with information about the outdoor air temperature. If the ground is wet and it's freezing outside, the system would engage. It isn't wasting energy on days that are only cold or wet. Although it uses energy to melt the snow, it uses the worst, most useless heat the building produces. Because it only needs to be barely above freezing, it can use whatever heat is left over after the boilers have heated the building. This means there isn't a dedicated boiler for this system that only works a few days a year, or even a larger boiler required for the building overall. Instead there would be a heat exchanger and a smaller local pump to run this system only as needed.
this is super informative and probably the most likely type of system they use. thanks for your knowledge!
Question about this, how is the ice build up around the heated area? Thats always been a concern of mine for doing something similar for a driveway and the like. I'd hate to have the run off water freeze into pour conditions for anyone walking by.
i’ve never noticed any significant ice buildup
> this sub had everyone concerned about the environmental impact of heated sidewalks, Ignore those lunatics.
Probably less impactful than a dude in an F350 throwing salt, following around 3 others dudes shoveling the sidewalks.
That makes a lot of sense. And good on your workplace for investing in that stuff with the long term picture in mind.
>i work at a hospital, Explanation complete. No need to justify further why the sick and injured could use a non-icy walkway. I mean, good idea in lots of places, but I have vivid memories of having to go out and salt/shovel the walkway at the clinic I worked so patients would stop seemingly aiming for the iciest route possible.
They typically are not on full time either. Used when needed.
What's the environmental impact of using gas-powered machines to plow everything?
How much energy does it use? I imagine the price for this to be pretty high.
Isn't pavement heating normally done with residual heat? I swear I read something along those lines a few years back.
Can you cook an egg on it?
Given that the temperature required to keep it melted is lower than that of a refrigerator I'd have to say no.
We have those in Austin too, but only in the summer.
When's summer start, next week?
3 weeks ago. 80+
80+ is just the beginning of spring.
Bruh.
And they're solar powered thus more efficient and eco-friendly
*ba-dum-tss!*
This, but the *tss* is my foot burning as I "just quickly grab the mail."
It's no wonder we've developed such great BBQ down here. Every summer our George Foreman sidewalks flip on for 5 months of uninterrupted free use to anybody and everybody with something to sear.
[удалено]
Worker’s Compensation Professional here (certified) and I can confirm Slips/Trips/Falls are the #2 cause of injury and by far the most costly on the employer and painful for the emoloyee. #1 is ergonomic issues and that would include back injuries from shoveling or lifting snow. This is a great idea and it could (and likely will) literally save lives
Bonus points for being a hospital where far fewer liability issues that aren't workers are going to arise due to undissolved ice melt, unmelted ice, or snow/ice that was not removed due to the aforementioned injured workers. This is a great and perfect place for heated sidewalks. In fact, I would fully support a federal grant for the least climate hostile way to do this at every hospital that gets snow at least once per year on average.
(Certified by AMCOMP)
I can't remember where, but I distinctly remember reading about a city where the main downtown sidewalks were built just over top of the water pipes running water for the city. The water pipes needed to be heated during the harsh winters anyways, so the radiant heat which would normally be lost to the ground was used to warm the sidewalks. I'm not sure about the efficiency of such a system, or how well it would actually prevent ice and snow on sidewalks. But a key talking point was the extremely easy access and repair of the pipes under the sidewalk.
Here's a similar example. Video: https://vimeo.com/299474831 Article: https://www.mlive.com/business/west-michigan/2016/02/why_holland_spends_millions_to.html
This is a good application of heated sidewalks. High traffic area with sick and disabled people travelling. I used to work building custom homes and when you have heated driveways, sidewalks, garages, In floor heated basements, bathrooms, and laundry rooms for two people its a bit unethical
Well driveways are one thing, but under-floor heating can be more efficient than radiators indoors.
My grandma’s driveway is steep, I could see the benefit of having one instead of dumping 100s of pounds of salt on it every winter
Yeah. It's much more environmentally friendly to use renewable energy to do that job.
That's true in some applications. It is very rare to see baseboard heaters in my area in a new build anyway. I think the last time I saw one was for a garage. All forced air now.
Which is crazy in 2024 because when was the last time anyone asked the air for consent?
I heard Baseboard heaters were pretty bad at heating, that’s the main reason we don’t see them anymore. Makes it hard to place furniture too since the part of the wall it’s on is taken up by the heater. Been a long time since I’ve seen them anyways.
Yea the house I grew up in had alot of them. They're mostly always placed below a window. They were especially popular in areas with cheap hydropower.
Indoors it’s actually better to have heated floors than standard. Regular floors will bleed your heat into your crawlspace that needs to be recouped by space heating, using a heated floor means you can recoup that lost heat with less energy than what would be needed via space heating, and your feet aren’t freezing. It’s essentially topping off a leaking jug with a small trickle rather than a constant stream. I’m an energy science major and it took awhile for me to wrap my head around the idea. Anything outdoor for individual use is a bit wasteful though imo. This really is a perfect application.
I've done design work on fire stations and we would often put in slab heating for the apparatus bays that extend out past the bay doors to help keep snow and ice off the driving surfaces. We already need to provide some form of heat for the bays, so extending the heating loops out further can reduce man hours of labor and provide additional safety for emergency vehicles.
Depends on how much it snows. Google says having the driveway run is like a 50W bulb every square inch. But it isn't on 24/7, just for the snowfall hours. Heated garages don't have to be wasteful assuming they are well insulated. Obviously, the bigger the house for two people, the more wasteful it is in general.
> unethical Why? What's the ethical problem with it? Especially as renewable energy becomes more and more common
"I'm cold". "Go sit on the sidewalk."
I want to do this for my parents ... but the systems I've found are expensive, about $250 for 6 feet. I wonder how much electricity this uses as well. Great for businesses, institutions, and municipalities... maybe out of reach for many home owners.
These are typically heated with propane or gas fired boilers. But they do get expensive to operate either way. A driveway about 40’ long for a 2 car driveway could cost as much to operate as the heating for the house for a season. This can vary quite a bit depending on how much snow there is.
Wow, that's more energy than I'd expect. You try to keep your house 70F +/-, I'd imagine you only need to keep the sidewalk above freezing so 35F would likely be fine, right? I'd think this would be far less energy than that needed to heat a home.
The rate of cooling from the slabs surrounded by cold air and elements is probably high. Just freezing air and snow sucking away heat.
It's the rate of cooling from an uninsulated surface, as you describe, PLUS the phase change from snow to water is a lot more energy intensive than people realize. That said, there's no need to be running these off of propane or the electric grid. A heat pump/transfer system could be used to disperse the cold deeper underground, or even to outside/surrounding air*. *I am not an engineer. I just don't see why not.
Your house is (hopefully) insulated, so once it gets to 70F, it takes almost no energy to keep it there.
I looked into it years ago. A man installed a wood fired boiler. He had to start feeding it the day before the forecasted snow. Then for it to keep up with the snow, it was steady feeding the fire box for the boiler to keep up during the snow fall. He figured he'd burn enough wood to warm his home for a week everytime it was a significant dump.
> You try to keep your house 70F +/-, I'd imagine you only need to keep the sidewalk above freezing so 35F would likely be fine, right? same amount of energy! heating water from 32->70 == heating ice from 32 to water 32
Glycol loop is super old school, modern method is multiple electrical resistant loops - reduces peak energy demand by heating in sections only as necessary.
You can zone glycol loops. Local city just put a bunch of that in for a city walk. Electric boiler, hydronic pumped and separate zones.
I looked into some melters for my deck and stairs. The cost to run wasn't bad because they only had to be a little warmer than freezing to work. They only need to be on during snow accumulation times, not 24/7, so the electricity costs aren't too bad. But ultimately, I didn't make the purchase and with this year's very dry weather, it was a good move.
The electricity used is most worrying part about heated side walk
If I build a house in the future I’m definitely considering heated entryways and driveways
Very cool. I wish I had that at my house. I hate shovelling and sometimes it’s icy
It's actually not cool, it's heated. ;)
It’s still snowing out there? (Sorry live in FL)
we’ve actually basically had no snow this winter. this is the first snow we’ve had in months.
I honestly thought we would see no snow this year
me too. i’m honestly okay with this storm. all the snow will be gone in a couple weeks anyway
You had a snow debt and now it's coming to collect
Hello fellow northerner This winter was honestly godsend for me (was living in my car) but man, with how warm this winter was and the sudden snow dump, it's crazy people don't believe in global warming
its nice having some sort of winter. wish it was during christmas though lol
Idk where OP lives, but March and April are historically the snowiest months in Denver
yep - got some sick thundersnow last night
I live in Michigan and not even the northern part of it. We got ~5 inches of snow on Friday. It is 60 out today. Weather be trippin.
Wait heated sidewalks exist?!?
And driveways!
And houses!
The discussions are more heated.
true that lol
It looks like a very sensible use of depleted Uranium.
nice! I suggest heating the entire Canada so we don't have to suffer through winter.
It's already happening :) I'm glad you purchased the Canada Warming package, which is part of our Global Warming Series.
Many years ago the university my folks work at was trying to recruit a new Chancellor. The job comes with use of this gorgeous historic Chancellor's house on campus. Well for this asshole it wasn't good enough, and they demanded the University build them a brand new house in the fanciest part down, and specified that it had to have heated sidewalks and driveways, even though we rarely get more than a few days of snow a year. We'll ofc that year we had a big snowfall. And I don't know how, but a number of local homeless found her heated driveway and setup camp there. 😂😂
This also has the advantage that it prevents the water from turning into ice. Eventually with salt the water freezes flat and leaving it unsalted would have been safer. So you end up needing to keep adding salt till it dries. I live in Canada and people new to the winter season from warmer countries make this mistake. Throw salt down after shovelling while the snow is still falling, go to bed and wake up to snow covered ice the next day.
Work put a set in after my fatal (I got better- brain injury, coma, etc.) slip and fall. I really appreciated it.
Surely you mean near-fatal. If not, condolences for your death
Hence the Monty Python quote…. Brain injury, body went into ANS shutdown. Breathing, nope. Heart - fibrillation. Pain oh so much damn pain. Ended up in a coma with machinery keeping me running until the bleeding in my brain stopped. r/TBI can explain it, but it sucks. Wear a damn helmet !
Glad you pulled through!
[удалено]
commercial properties are built with drainage in mind
My parents put in a heated driveway a few years ago and they got a ton of push back from people saying it was an unnecessary expense it cost them about $28k but they constantly talk about how it was worth every cent
Michigan State University has an on-campus power plant and uses the excess steam to heat the sidewalks. It was real nice.
We have these at the urgent care clinics I do HVAC for! Overall, these aren’t terrible for the environment, as at least on our sites with heated sidewalks we use solar power which greatly cuts down on the environmental costs of heating the sidewalks. They also allow the sidewalks to last longer, so less concrete and construction materials used over the lifespan of the sidewalks, they are safer and they dont use road salt which is terrible for the environment. Thanks to the glycol in the water the system doesn’t need to run at more than probably 50-55 degrees, so its not like we are dumping 120 degree water outside.
I wonder why this combination isn't more common. Sidewalk that doesn't get enough sun to melt ice + solar hot water from elsewhere seems like it would be a winning combination.
A big thing is cost of installation and the remodeling that needs to be done in order to achieve this. It is a big upfront cost to install these systems and honestly most building owners dont care enough to pay for them. Unless they are already redoing the entire HVAC system, it isn’t cost effective to change out the building piping, boiler, and existing pumps to accommodate the glycol necessary to make these systems work. If you are building a new building this becomes a lot more feasible, but again, all of that depends on whether it is “owner occupied” or if it’s being rented (that, and, do you trust the tenants to upkeep the boiler system properly). I still love them though and I think this type of design is where we are heading in the future of construction, generally.
In my city, we have 2 whole blocks heated this way by district heating. Costs yearly around 400000€. It’s just water in those pipes that heat it up.
Most importantly, is the grass under that snow dead? Or dormant? I'd hate to see everyone come at you again.
Had a boss from Austin buy a vacation home in Utah. The place in Utah had a heated driveway. He wasn’t one for details…turned it on…left it on…the electric bill was his first clue.
Are these things hard to set up? Pouring concrete on electric heating elements?
They're not electric, it's typically a heated glycol solution (read: antifreeze) run through flexible PEX pipe. It's tied down to metal mesh in an organized manner and they pour concrete on it though, yes.
The sidewalk is dope but I’m more impressed that most of those trucks did not block it. Would never happen where I am
Loving the late winter here in Minnesota... *and by next week it'll all be gone*
My college tried this, but half-assed it. In the winter when it snowed, the sidewalks turned into sheet ice. You could always tell who were freshman because they were walking (and slipping) on the sidewalks instead of walking in the snow next to it.
N(o)ICE
If we did this here the pavement would be overun by cats. Nice to pet though as you walk past if you're not allergic.
Holland, MI?
We have this on most sidewalks in my city centre.
That’s so hot
What blew my mind in Japan in the winter is - they have enough hot springs that they pipe hot spring water to bubble up on to the roads and melt snow. Very elegant and probably low carbon way of keeping the roads clear with geothermal.
Wow! Heated sidewalks! In almost 20 years my employer has never repaved the parking lot or even filled in the potholes.
well hopefully they are at least paying you well after 20 years!
I remember someone was looking at using Fatty Acid Methyl Esters to cause the concrete to heat up to like...34F once it got snow on it so that it'd melt itself.
Snow removers hate this one simple trick
How warm is it to touch? Still cold feeling but enough to melt ice, warm, hottt? I imagine its most cost effective / energy efficient to warm juuuuust enough to melt things and keep ice at bay, but that doesnt mean they did it that way and idk how the system might determine how warm it needs to be to do the job so maybe it just has a single setting, maybe not. But yea - have you touched it with your bare hand for science yet OP?
It's probably not warm/hot, the sidewalk just needs to be heated to above 32° to melt the snow/ice
Smart!! I’ll bet their insurance went way way down.
If it breaks down though, does the water then form a nice smooth coating of slippery slippery ice?
if it breaks down then they just salt it and clear it like they do with the rest of the sidewalks
It's all gravy until the power goes out
they have backup generators and can always just clear the sidewalks the normal way
Do you know how much heat they use each m2? And how hot does the stone gets?
I'm always blown away by how much snow people get... its 75f here outside and looks like we'll be in the 80s rest of the week.
I need this on my driveway like yesterday!
What’s that funny white stuff? We don’t get that in southern England. (Same long as Edmonton cananda) thank you North Atlantic current
How much do these things cost?
I can't imagine living in a place that gets this much snow in late March.
How are these made?
What are their names?
Does the sidewalk not get slippery from the melted snow? I live in a desert so I know nothing about this