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They are in front of the elevators at an outdoor multi story parking garage around my area. That's all I wanted to share, thanks.
Those particular ones might be a waste of energy, but outdoor heaters like that in general are great for in front of hotels, and in the vestibule for doormen at clubs or valets
I responded further down but the infrared equivalent to these are very useful and explicitly solve for the energy waste issue you describe. Infrared heaters can’t heat open air which means heat-energy is transferred right to solid surfaces. It is extremely efficient in areas with any amount of airflow as the heat isn’t able to be blown away as it’s radiating from the surfaces below the heater, not the heater or the air between.
I bet we can take it even further. Switch it out for a phased array of infrared emitters that track and target people based on body temperature. Then it won't have to be on all the time and there's no way it could possibly go wrong.
Nah we can go way further, what we need is to switch from infrared to microwaves. By emitting microwaves at the right frequency, we can directly transfer energy in a super efficient way. We could tune it to make water molecules vibrate and turn that energy directly into heat. Since humans are basically bags of water, they'd be pretty warm without much energy required at all.
Being around microwaves like that has been proven to melt chocolate bars in pockets, though.
That might work. You could use masers, but I think, in the interest of costs, a cavity magnetron and waveguide would be a better choice for generating the microwaves. You'd have to build a large metal cage around the area with the gaps being smaller than the wavelength to make sure you weren't heating anything unintended or causing electrical interference to nearby devices/circuits.
There'll be the problem of the resultant interference pattern in the--what should we call this?--microwave sauna, creating cold and hot spots. You could set it up so the magnetron and waveguide move around, but that's a failure point centered on the most expensive components. It would probably be wiser to put a rotating platform in the sauna to move the subjects through the bands of positive and negative interference for more even heating.
You'll probably need to have controls for power level and time. Can't have the thing on full blast constantly or people will get a little too warm. Those controls will have to be on the outside, so they don't receive interference from the microwaves. Also, it'll be really important to educate people not to bring metal with sharp edges into the sauna, otherwise the potential difference between the magnetron and the point/edge of the metal can overcome the electrical resistance of air, creating a plasma arc that could short the whole thing and electrify whatever the metal is connected to. It needn't be a long list of banned items, just simple things like cell phones, bank cards with chips, zippers, keys, jewelry, dog tags etc.
One of the coolest things about this solution is based on the fact that corn kernels have the moisture to absorb enough energy from the microwaves to make steam and cook internally until they rupture, forming a tasty snack. You could totally put a button on the control panel for making popcorn.
"All we found was a pile of ashes."
We haven't heard any complaints, though! Just the distant sizzling sound of contentment.
Better yet, people just wear better clothes and retain body heat instead of sticking heaters outside.
With respect, I fail to see how that advances shareholder value. How would you even build a recurring monthly fee into the use of clothes?
Im wondering how large a phased array of infrared sources would be
And usually they are infrared so you're only heating people, not concrete.
I dont know how people absorb infared vs concrete, but i do know that once it emits a photon of infared, that energy is gone from the system, regardless of where it is absorbed. Meaning you spend the exact same power heating nothing as heating the air, concrete, or people. As long as the heater is emitting, it is emitting the same amount always.
This parapraph began as a short tangent but now i have a longer question. I was going to explain that the energy delivered does chnage if you prevent the energy from escaping, but now im not sure exactly how. If you, say, reflect all the ir back at the emitter it heats up. Therefore, it emits more blackbody radiation. Im just gonna take a guess and say that blackbody radiation is not the mechanism by which quartz ir heaters operate though. Im assuming they operate closer to an LED, where they are doing fancy quantum magic to directly create the chosen photon and the chosen amplitude, which would be way more efficient. In that case, as the emitter heats up it would have a lower efficiency because the electrical resistance goes up, wasting power. It would also serve to expand the bandgap in the IRED, either reducing efficiency or pushing it into another frequency of light altogether.
However, all that "wasted energy" or "reduced efficiency" has another name... heat. And its a heater. So like.... net energy generation stays the same? I think my confusion is coming from not clearly defining what it actually is im trying to measure or where im taking that measurement.
They are there to stop ice from forming on the walkway of the entrance. There are more for safety than heating.
I don't think that's how radiant heat transfer works. Should generally heat anything colder than the heat source
Kinda both right, it heats surfaces the infrared energy emitted by the heater can make contact with. It won’t heat open air which makes it extremely useful in outside environments or anywhere with a potential for airflow.
Why do you think concrete does not get heated?
Elderly and young children's natural thermostats don't regulate as quickly as others ', either.
I'll agree that they have very specific locations where they have reasonable use cases, but the vast majority of where they're located are a waste. Like you mentioned, specifically somewhere with dry desert conditions, where it can get very cold at night rapidly where people are tourists and not dressed properly.
I don't know about this use case but we have them at transit stations and some major bus stops. They make really bad days bearable and I would say are a necesity. Granted they are on demand so you hit a button and get a few minutes and if no one is around they stay off.
They do suck but CTA stops in Chicago have these and they're better than nothing in the brutal cold. A lifesaver when the train is going to take a while
It really depends on the use case. These “shoot” the heat directly onto the surface, instead of heating the air and pushing that air in a direction.
If you’re standing under them for long periods of time, they’ll (generally) be a better option in a cold environment, since it’s directly heating you instead of the air.
But if you’re just walking under them for a moment, or if it is meant to be a kind of “heat boundary”, heated air is going to be the better option.
Considering placement, I'm willing to bet these are intended for heating the walkway, not people. People with snowy shoes standing around waiting for an elevator are making puddles, and without a heater, the puddles will turn to ice right on the one part of the parking garage that nearly everyone will be walking on.
Oh that’s a really good point I hadn’t thought of. That would make sense.
It's only a waste if you are generating that electricity from non-renewables. If the electric is coming from nuclear or renewable AND there is enough electricity where you are then there's basically no harm. Electric heat is 100% efficient since all the energy is consumed for its intended purpose.
I get what you're saying, but I disagree. If you don't use this heater but send the renewable electricity to the grid instead, somewhere non-renewable energy doesn't have to be used. IMO your argument is the same as the reason energy efficiency leads to more energy consumption. I quickly googled it to make sure I'm not talking out of my ass, and it's called Jevon's paradox.
So what your saying is that switching to renewable is pointless because we aren't allowed to use the energy for what we want?
Of course not, didn't you read the second sentence? I'm saying making renewable energy just so you can waste it doesn't help much.
It's not a waste if it makes people more comfortable
Hm, the efficiency point is a bit moot, you can say the same for coal, oil and gas.
You definitely cannot. All of those materials burn and release carbon. Not 100% of the material goes towards energy. Solar for instance produces electricity with no byproduct (excluding the cost to make the panel). There are no byproducts in the generation stage. We then transport the electric which also produces heat.
Even worse are places that leave their doors open with the AC blasting in the middle of summer. Yah, let's try to cool the atmosphere.
Swampy / evaporative coolers are a thing that are effective when windows / doors are open.
I see a lot of propane ones