Short High School Engineering Project Survey

You know, they could program the door to offer more resistance to gentlemen, and less to the ladies, and in fact, the energy used by the beefier ones in the crowd could help the ladies (especially the little old ladies, or the infirm) gain access.

That way, it makes sense, but I would count on it contributing to the comfort level of the interior spaces.

I agree, if you want me to generate electricity, I'll need justifiable compensation...Nobody likes doors that are hard to open, and it's only a matter of time before someone wedges the door open...Besides everybody knows that automatic doors are the future....Open Sesame...

He asked the forum to answer a few survey questions. Nothing more.

..."We are looking for some feedback on the viability of one of our ideas."...

Well why are you posting?
Del (see what I did there?)

By the 'more' in "Nothing more", are you referrimg to things such as comment #14?

Thank you for the feedback. We will certainly take the product you linked into consideration and investigate it further. We are hoping to create a product that is more commercially viable and that wouldn't power itself (instead maybe connecting to the grid). We hope to create a product to be used in high traffic areas so the system would see many uses throughout the day and would generate a substantial sum of power. As you mentioned the potential energy generation must be looked into and the resistance requirements have to be taken into consideration.

Thanks again for your input,

Engineering Team

Make energy when students walking, then stored in a big battery.

I like the idea of parasitic power generation in general but I think using the movement of a door, regardless of the amount of traffic, will not be productive. I say this because a requirement of using a door is that a door returns to the same point. So the net amount of work performed on the door must be zero or the door will not close. Along the way real losses of energy (e.g. wind, friction) happen in both directions of motion. A self closing door whether using springs, gravity or other energy storage form must store and release enough energy to close the door and overcome those losses. To harvest more energy will mean an even bigger load to whatever opens the door. You have to be careful to not expect more energy capability than a small child or other frail being that will be using this door.

However, I have no idea how you intend to achieve this energy harvesting nor the magnitude of power and energy you anticipate to harvest. So despite my earlier comments I say go for it. By design all of the forces and energies of this project must be in a safe range for a person. Meticulously document everything you do, measure and analyze.

You should learn a lot from this project.

No, revolving doors present many, many problems. Too many losses to consider here.

Along the line of an 'UP' escalator being energized by the individuals riding the 'DOWN' side.

"... I think using the movement of a door, regardless of the amount of traffic, will not be productive. I say this because a requirement of using a door is that a door returns to the same point. .So the net amount of work performed on the door must be zero or the door will not close..."

.

I don't think returning to the same point puts any prohibition on productivity of energy harvesting.

It's a thought proving comment you've edited to the point of obscurity. James' and Doorman's comment on a revolving door show they caught the thought. (And James thought I always disapproved all of his comments. Pshaw. )

"...edited to the point of obscurity..."

Please forgive me for knocking your thought out of the spotlight of fame. I had no idea the thought was anything but obscure. Moreover, the 'editing' of which you speak is as unobvious as the obfuscation of the thought's fame.

Any assistance you can provide to unravel this mystery will not only help set me straight, but might even get your thought on the path to regain its former renoun,

You and James must have been classmates.

Your opinions, and that's all they are is "your opinions", must take precedence over all others?

Now, perhaps you can, once again, critique my opinions for the forum? I'm sure they are all waiting breathlessly for your proclamations.

"...precedence over all others...."

How do you figure?

By the way, other than the question mark, yoir sentence is not structured as a question. (Please also note that despite being my opinion, it is also a fact. Those two don't always coincide, but are by no means mutually exclusive.)

.

Now, take a moment and consider which comment is more appropriate for an engineering site:

a) my comment calling into question an implied prohibition on the ability of something to yield usable energy if that thing returns to the same position, i.e. no net work was done on the something.

Or

b) your curmudgeonly hurrumph, about imagined orders of precedence supposedly imposed on the delicate sense of readers.

.

Might I have your opinion on this matter?

Thanks. I'll try to be literal when posting and dispense with subtleties.

I am withdrawing from any future comments so as to clear the way for more meaningful discussion.

Just 99% of the time, good buddy, Fred of the Red. Cheers!

The problem I see with a "normal" hinged door as prime mover: in heavy foot traffic the door might not move at all.

A revolving door on the other hand will rotate more times, and perhaps slightly faster in heavy foot traffic.

A swinging door (interior) with a typical width of 36" swinging in a typical arc of about 110° takes up about 8-1/2 square feet of floor space. A 3-wing revolving door with diameter 96" takes up about 50 Sq Ft of floor space. Cost of construction today is commonly measured as dollars per square foot: In my part of the world, about $150 bucks a foot is average for an elementary school or a nice office building. So, a swing door occupies about $1,300 bucks of floor, while a revolving door takes about $7,500 bucks worth. This doesn't take into account the difference in costs of the doors themselves.

Now, let's get some filing cabinets, desks, tables, a copy machine, etc, through the door.

at 5 KWh/day, the revolving will never pay for itself, much less its own electric gear.

at 15 KWh/day, maybe in 25 years or so.

You can do the swinging door one, I am out of here for the weekend.

Also, schools qualify as (gathering places),

which therefore, have to meet the (local Fire Codes),

which tend to require exit doors with (panic bars),

which, in turn, would tend to preclude the use of revolving doors in schools...

Revolving doors can be considered part of the required exit path if constructed so the wings collapse in the direction of exit.

Revolving doors are pretty much a mission-specific item, very seldom used because of the many, many maintenance issues involved and floorspace consumed,

Revolving doors are, despite all the drawbacks, pretty awesome mechanisms! They are not a candidate for consideration in an energy harvesting scheme.

I thought they would be ideal for energy harvesting since the direction of rotation would be consistent.

The idea of parasitically harvesting the human energy spent to operate a revolving door has already been put to the test. Our friends at Gizmodo have an article about it. The comment string at the end of the article is an interesting read.

If the application being considered is already a candidate for a revolving door, and the original expense, lost floorspace, and maintenance issues are already acceptable, then this is a viable scheme worthy of consideration. With the numbers cited in the Gizmodo article, that door generates about $50 bucks a month of energy.

Boon Edam is a very progressive organization. Their NRG+ TQ door is offered to those wishing to "...tell visitors that the occupants care about the environment and strive to build a sustainable future."

Now, is this an engineering solution to a real world problem? Dunno,

I suspect that doors waste far more energy in the passage of occupants in/out of all types concerned, both occupants and doors, and that time would be better spent in designing a better air-lock system for occupants, so that less heat is lost during transit.

It seems to me that every school is a revolving door of "free" education - indebted education - employment (to pay the debts) - taxation (to pay for the "free" education).

Why not abolish school (property taxes, and the estate tax) and establish a pay for education system where the schooling is paid for up front, or Little Johnny goes to the work program for children of parents that cannot or will not pay up front. That way Little Johnny get OJT, and pays his way in school.

The present system is pernicious in the sense that landed members of the community wind up paying for all the free-loaders.

Harrumph.

“He who opens a school door, closes a prison.”
Victor Hugo

“If you think education is expensive, try ignorance.”
Andy McIntyre

I expect nothing less from you. Harrumph indeed.

Indoctrination is expensive, education is free, because knowledge and wisdom cry out in the streets. Indoctrination and ignorance are first cousins. It is completely possible to pass through the school system with no true education, no analytical thinking process instilled, but plenty of ignorance and indoctrination, just saying.

There are also quite a few, perhaps not the majority of persons, but quite a few edumacated educated persons in prisons - mostly the one that thought themselves smarter than anyone else.

"There are also quite a few, perhaps not the majority of persons, but quite a few edumacated educated persons in prisons - mostly the one that thought themselves smarter than anyone else."

I believe there is something to this observation. You touch here on something I observe, "...mostly the one that thought themselves smarter than anyone else." Dunning-Kruger effect and hubris are traits of personality, not instruction that is ladled out in public education.

That is also true.

Thanks for the stimulating discussion on the matter.

Sorry, but I have to philosophize here:

You can lead a student to class. But you can't make him thirsty to learn.

Until you value the lesson, you won't value the learning.

Where a dog's nose goes, the dog follows.

Is this why the north pointing dog is sniffing the south parts of the other north pointing dog?

Good education always makes every effort to provide examples of how the mathematics, history, or biology applies to real life. Same applies to other subject matter.

If in opening the door each person has to exert more force. They then will then burn more energy. Which will require them to consume more food to replensh the energy spent. Which means we will now have to plant and grow more crops to make up for energy spent. Tractors used in farming run on fuel so they will burn more on the extra ground need to grow the extra food. The proceesing plants will run longer consuming more energy. Trucking to haul extra food to the markets burn fuel.

How does this solve a real world problem? There is already the problem of feeding the all the people. That will only make it worse.

As some one all ready pointed out nothings free.

Mite be do able if you just put them on all the gyms. People get work out getting in and out of the building.

I getta de job, I digga de ditch, I getta de check, I buya de sandwich, I eata de sandwich, I digga de ditch. See how it supposed to work?

Based on fat couch potatoes in most office buildings, they need more than a couple of trips through a resisting revolving door.

I would very much like to know where you purchase the monstrously large brushes that you use when you make comments like this.

In the interest of avoidance, I would also like to know which techniques your sensitivity coach has used - none of them seem to have been very effective.

Big Lots, where else?

Who cares about sensitivity training. I was busy building molecules, when that class was held.

I could not care one iota about PC. I am here for results.

The only coaches I ever had were sports coaches, football, basketball, and golf.

The golf coach never swore, never physically assaulted me to get me to play better,

the football coach, even after I had a taped up broken ankle would just pinch me hard on the back of my thigh, smack my helmet, and yell "Get your butt back in there and block, and stay there on defense, and for crying out loud, tackle somebody!

Basketball coach, he would just grin and make me run lines the entire practice. My shooting average did not suffer, and a lost a few unneeded pounds (needed to be lost). Every time I missed a play in practice, it was back to running lines.

We nearly made the State of Texas final championship rounds in golf, missed only by 1 stroke at the regional.

Not really. I stayed in Texas during college, but went to Utah for my advanced degree.

I did ace most all of my tests, but got a "B" in political science at McMurry, because the perfessur did not like me - it was a mutual feeling.

I hope you, Lyn, and Doorman, are each having a splendid day today, and I am here to jest and poke in fun at you, and I appreciate any ribbing I get in return.

I hope that your embarrassments are minor ones, your successes good ones, and that you remember to love your wives, and hug your dogs.

It is spelled hobbyist.

Hobby, hobbier, hobbiest.

"He is the hobbiest Calvin in the realm."

Thank you for the feedback. We were imagining a similar solution.

We appreciate your time,

Engineering Team

I answered the survey questions.

I thought it was worthwhile and not intrusive.

I gave no advice, because it wasn't asked for.

I read the commentary in your post above.

I thought is was mildly informative as a relevant observation.

I decided to heed your warning and made no attempt to gather advice from a place where none was provided (and explicitly noted as so).

Nice and simple survey. I like the implications of the last two questions for possible stratification against our claimed qualifications in an earlier question.

They could review whether the educational level achieved influences the "feasibility" opinions.

If they are reading this thread, maybe putting the energy gathering device under the door threshold/mat might be investigated. As each person passes, their weight causes some deflection against spring return, or other mechanism.

Good luck to them and their inquisitive minds.

Nah, if we could just harness all the hot air, being issued forth from the mouths of all participants on CR4 blog, they would have a winner.

Given that there are so many obese people in the world doing away with stairs and fitting a moving beltway that meant actually using the legs to surmount could generate power and help the fat problem all at once.

That survey was so broad & vague, I don't know how anything meaningful could be gotten from it. Please take this survey so I know if my response was worth the effort:

1. Do you think surveys are worthwhile?

0 Yes 0 No 0 Maybe

2. Do you think asking questions produce meaningful answers?

0 Yes 0 No 0 Maybe

3. Do you think people taking surveys are good communicators?

o Yes 0 No 0 Maybe

4. If this was an essay question, how would you answer it?

0 Yes 0 No 0 Maybe

I liked the 2nd survey about the monkey.

Hmmm... electrified doors for humans? I was hoping for power generating doors on chicken coops to produce cheap fried eggs.

good one, but you would most likely prefer the eggs to be fried after removal of the chicken coop poop (and the shell).

Now, don't get me wrong, I love me some fried chicken, but usually without the guts and feathers.

Can you use the power captured from the big guys barging through the doors to aid those less able?

Post # 11 has a good harvesting strategy which could have an implementation which would not increase the effort requirement up to the point of impeding handicapped or youthful door operators. These "harvesting" schemes generally do not produce meaningful power unless that power is exclusively used locally for communicating some control information so I answered "maybe" on your question about being worthwhile.

A worthwhile example might be a collision prevention light on an opaque door. Bathroom or commercial kitchen doors come to mind. Low energy sensors such as normally-open switch mats would turn on LED's as you approach a door, the LED's would show that it recognizes your approach and is not power depleted, additional LED's or LED color would indicate whether someone else is approaching the door from the opposite side, if someone is, the door will select the priority door user and warn the lower priority door user to stop well beyond the swing of the door. The selection could be pre-chosen as first-come-first served, leaving wins, entering wins, or any number of potentially more sophisticated decision algorithms including fire marshal capacity limits counters, etc. Super low power microprocessors are available at very low cost and non-volatile memories could retain parameters even at significantly depleted energy levels. No light at all as one approaches means: not currently working, use additional caution and revert to human procedures.

Any remote power use or any thought of saving significant amounts of money with lower power bills are, in my fairly-well-informed opinion, return-on-investment fantasies. I assert that they should remain so until one has measured the power accumulated to be economically worthwhile with data collection using these same real life, practical control-signal-only applications in a process I call: innovation boot-strapping. Hmmm, sounds like a good book title.

thewildotter

Oops ! I should have said "energy accumulated over time" instead of "power accumulated". Power does not accumulate but energy over time is power. I was being a bit casual with my terms. I just do not want to mislead anyone so I decided to clarify.

Well, that's the difference between being right or wrong. That's what science is all about. Truth and accuracy in technology. The smallest of things can stop something from working. I'd rather have something that works. "Close enough" is only good enough with hand grenades and atom bombs.

You left out a game of horse shoes.

Dennis,
Yes, you are MOSTLY right as James pointed out. As far as things that really count, I would like to include focus(where one applies ones attention) and request that you review the upper limit of the energy available from a door(even one in a
very high traffic area) over the period of 1 year.

Per the article linked in post #51:
"Our friends at Gizmodo have an article about it."
Have you tried a sanity check on this article ?
If I have made no new errors, it seems that:
24hr/day * 7days/week * 52weeks/year = 8736hours/year
From the article, the door at that venue can
produce 4600kwh per year.

4600/8736 ~ 0.527 kw (about 500w) continuously every single hour, day and night, seven days a week, the whole year long...

or 1000w with a 50% duty cycle.

First, I would like to ask each responder (yes/no) if you have ever used a bicycle generator to attempt to run a 100w light bulb at full brightness even for a short period(please specify) of time ?

Some science fairs run these timed 100w demos as a way to get attendees participating so do not assume that 100w is the size of the light on your bike(yours probably is lower wattage.)

I await your answers, corrections, and especially your comments on these door observations. No criticism intended here(either of you or of Doorman #51), I just want other defenders of the faith to review the statements and facts. I have interest in peer reviews of wildly spectacular media reports. I also invite anyone else to estimate the energy available from a person-actuated-door over a year.

I just strive to gently guide your focus. I am looking for a reasonable kwh number for the energy one can reasonably expect to glean in the period of one year from a non-obstructive increase in the effort required to operate a well-built, well-designed, (say 100lb., mildly-geriatric) only-public-transportation-using person compatible
(revolving is OK) energy-harvesting door. I want this even if you (surprisingly)agree with Gizmodo but please provide more than just an emotive explanation("Because it appears online or because a site with a cool name like Gizmodo must be authoritative or even some random entepreneurial PhD which Gizmodo interviewed said so" is utterly uninteresting without supporting detail.)
Dennis ? Doorman ? James ? OP ? Others ?
Please weigh in !

I have tried to produce my own energy from my own work. I know it's small. But, something is better than nothing. When I first returned home, I had nothing. Not even running water or heat. I was desperate for anything. This was the first time I really appreciated being an electrician (I tried to to avoid it like the plague in high school, and tried to be a Machinist's Mate in the Navy. But oh no, they had to make me an electrician). I took small motors apart to see if I could convert the rotors into an energized field for a generator and rectify the output to charge batteries. Took an old bicycle for the prime mover, and tried to supply lights with it. Didn't get much, but it was better than nothing. From there I was able to finally get a job and save up for other things. If anything, I would suggest that exercise equipment be converted to electrical prime-movers, and stop wasting that energy. But no, people would rather pay to go to the gym and waste their time and money on their appearance than appear to be poor. To hell with efficiency, extravagant waste is "cooler".

What always made me laugh was a three story gym I saw in Manhattan. Not once did I see a person take the stairs to the third floor stair machines. They always took the elevator to go up and down. Since the showers were in the basement those elevators were always ripe.

Although a well-trained bicyclist might be able to just produce 1 kW bursts of power, sustained values are nearer to 400 W. Average fit human can produce from 50-150 W power on a sustained basis, and average worker will go about 75 W during his/her shift.

This suggests that a realistic value of power to be obtained from any door will be in the 50 W +/- 30% zone. This is 10 times lower than the estimate in your link.

50 * 8736 = 436,800 W-hr (436.8 kW-hr), at $0.15, this amounts to a grand yearly total of $65.52. This makes any such effort have a nil pay-back expectation, in other words, it will never pay for itself.

There are places that sell gym equipment that generates electricity, and the vendors will be quick to suggest that lowering of utility bills is the result. It gains power by the parallel application of many generators of a small nature.

It would seem to be more of a ( semi-competitive? ) alternative, rather than a viable solution...

Orrrrrr, since cars are going to drive into into your school parking lot(s) in the morning, and back out again in the evening, they are a potential source of energy, as yet untapped...

If you ran wire loops that looked like traffic counting (conduits) across the entrance to the school parking lot(s), then each car would tend to induce a small, transient current in each loop...

It might be a good project to try to (harness) enough electrical energy in a battery (array) to power a sliding, self-opening door, sustainably, depending on how long the loops lasted, etc., ...

It might well not work, and it might not pay for itself, but it would still be a good project to quantify how much electrical energy could be so gathered, with how many loops, of what size wires, in how many batteries, etc., ... as kind of a group Science Fair project...

If we are so dead-set on autonomous/electric powered cars, why not go a step further, and have passenger bubbles on the chassis of each, and let them pull up to the suction tube whence the bubble gets picked off the chassis, transmitted to Little Johnny's classroom, and deposited there with him still inside where he cannot sneeze on the other children? This prevents the upper-crust (Little Johnny) from contaminating and sickening the better children.

If Little Johnny does not preform well, his bubble drops out of the classroom through a trap door and deposited back on (another) chassis whereupon he is transported directly to the prison work farm.