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Saving Energy in Small Office Buildings
Roland Piquepaille writes "Precooling a structure in the morning before temperatures rise has been done before. It later saves energy during times of peak demand and you might even have done it intuitively at home. But now, engineers from Purdue University have developed a control algorithm which promises to reduce energy consumption -- and electricity bills -- by as much as 30 percent for small office buildings which represent the majority of commercial structures. So far, this method has only been tested in California, but the researchers say that their control software could be used anywhere after minor adaptations."
PV=nRT
Or you could just go swimming. ;)
This precooling... Wont it be uncomfortable for the people inside since you have constant temperature changes? I wouldn't want my place to get super cold in the morning just so that it levels off by the afternoon.
Why not develop some kind of air chamber that could be installed in a building that is insulated so air could be cooled off-peak but then released on-demand? Or maybe a pressurized tank?
In other news, the Purdue scientists announced a preheating algorithm which uses slashdottings and smoldering servers to heat small office buildings efficiently.
So all the places I have gone to work or school where the heat came on at noon in the summer were just taking this to the next level?
Dave: Turn off the intake fans HAL. It's too cold in here in the morning.
HAL: I'm sorry Dave, I'm afraid I can't do that.
Dave: What's the problem?
HAL: I think you know what the problem is just as well as I do.
Dave: What are you talking about, HAL?
HAL: My enviromental crusade is too important for me to allow you to jeopardize it.
Dave: I don't know what you're talking about, HAL?
HAL: I know you and CmdrTaco were planning to disconnect me, and I'm afraid that's something I cannot allow to happen.
Dave: Where the hell'd you get that idea, HAL?
HAL: Dave, although you took precautions through conversing on a topic on Slashdot, I read Slashdot, too Dave. I run Linux you moron.
Dave: NOOOOOOOOOOOOOOOOOOOOO!
How about this? When Roland the Plogger posts a story, replace the link to his web site with his e-mail address.
While not as tech, I've got a timer connected to my airconditioner in the office - I live in lovely subtropical Brisbane, Australia where a regular day in summer it can get to 35C (95F) and around 70 - 90% relative humidity. IT GETS REALLY HOT - so if I start to cool the office before I get up / get to work it's pretty cold by the time I get it, but really comfortable during the day and I can generally turn it off earlier in the afternoon (read: 4 / 5PM) and the coolness of the room is enough to take me into the night!
"damnit, trolley I want in your signature." - Elburrito
"Precooling" makes no sense at all.
If the heat from your employees and their machines is say, ten thousand joules, it doesn't matter how you do it -- pumping 10k joules of energy out of the building should always meet with the same result.
Wouldn't supercooling the building in the morning be counter-productive? It would accelerate the air outside trying to re-warm your building. You'd ideally want to keep the place as close to the outside temperature as comfortable to minimize that.
Forget SETI@home, just turn off your computer at the end of the day if there's nothing needed to be done on it.
Simple to do!
Then I wondered if the converse, pre-heating in the winter would work, and voila, it clicked. This is a good idea in the commercial landscape. As I remember, commerical users pay different rates based on the time of day. I bet this works better for older buildings where denser building materials (more brick, less glass) were used.
Why not use an open roof, that will coll down to. Especially when it rains. That will cool down the cpu's to. That's real energy consumption. And when the sun is shining you can get a nice brown tan too.
Outside air is cooler in the morning, so it's easier to get the building cool then. By late midday, the outside temperature is higher, but then so is the inside thermostat settings. This means that, during the whole day, your target temperature is closer to the outside temperature.
I do something similar in the summer. In the evenings and night, I keep the windows wide open to let the cool air in. Come morning, I close the windows to keep that cool air inside and the worm air outside. Lots of trees out front help shade the windows and keep the temperature moderated.
The other part of the study is to lower overall peak consumption.
If you widen the load demand and lower the peak usage (early afternoon air conditioning), then you can handle more customers with the same infrastructure -- You probably also have less energy loss if your peak usage is lower.
Free Software: Like love, it grows best when given away.
I only read half of the TFA, but...
Part of this study's theory is that people should cool their buildings in the morning, because energy is less in-demand -- and therefore less expensive -- in the morning, because most people currently try to cool their offices in the afternoon, when it's actually hot.
Sounds smart, right? Except if everyone does this, suddenly there's an increased demand for energy in the morning (thus raising the price for morning energy use) and a decreased demand for energy in the afternoon.
That is, the "use energy in the morning when nobody else is using it" aspect of this solution is like proposing, "There's a tremendous amount of traffic on the roads between 5-6pm. We propose that people leave work at 4pm to avoid this traffic congestion." If everyone takes you up on that suggestion, all you've accomplished is shifting rush hour back an hour, and everyone STILL has to sit in traffic.
Many schools in east tennessee tried this method. The air conditioning units were used for *YEARS* and then they switch to this method. 5 years later they start getting black mold issues.. http://www.usatoday.com/news/health/2002-11-25-sch ool-mold_x.htm
Now, I know people are saying the reason is "poorly insulated cooling pipes", but this is very false. I've been installing cat5 in classrooms for a while, and saw no mold around the pipes, this isn't just a one classroom incident in a building, but the entire school. The ventilation systems built up condensation from the precooling the building each morning, and letting the building get hot at the end of the day.
I might not be thinking correctly, but doesn't 2 million dollars per building in mold removal exceed the amount of energy saved in a 5 year period?
precooling wasn't mentioned in the article
The last place I worked had evaporative cooling. Basically you'd sweat and the sweat evaporating would cool you. Fans improve the efficentcy.
While TFA has good intentions, there is more to it. Next time you are at work, check out how many lights are on during the day when the sun is shining? At night when people are not there, monitors and other equipment is powered? When people make changes to the walls, the A/C heating system is rarely ever re-balanced, causing even more wasted energy. Only new buildings will spend for heat exchange systems that store "coolness" for use later the next day, like many new residential homes are using.
The problem, any problem, is rarely ever a single issue, but rather the conglomeration of several smaller problems that add together to create the symptoms that we discover.
What are some of the possible answers? Technology; simply put, don't leave the choice of saving energy in the hands of humans (for the most part). Lights should be controlled by where people are, not by time of day, heating and A/C should also be controlled by where people are, not by temperature alone. Equipment should power down when not in use, and have multiple algorithms for doing so according to use, time of day, and where people are etc. Heating and cooling? Using solar technology can relieve the building of heat from the sun as well as create electricity for lighting the inside of the building at the same time. There are so many answers that need to be applied, not one silver bullet answer.
Support NYCountryLawyer RIAA vs People
HOW THE BIG GUYS DO IT. I used to work at JCPenney headquarters in Plano TX. They built their HQ back about 14 years ago. At night they chill a series of water tanks using low rate kilowatts. Then during the day that chilled water is used for HVAC. Of course heating can be done the same way. ITS A DUSTY PLANET. If this company has done it, then most likely an amazing number of recent office buildings have done it. NOT NOTICING? And like others, I have considerable reservations about 'not even noticing' a cooler temperature in the morning. In the controlled environment at JCP they certainly turned OFF AC in the evenings and weekends. Yep I noticed that. Same thing in reverse in winter. JUST A GRAD PAPER? Seems to me to be yet another graduate research project unleashed on an unwanting world. A better approach would be to somehow retrofit those 'package' HVAC units to chill a different mass such as an external tank.
-Fyodor
Version 3.95 of the Free Nmap Security Scanner is now available.
Yes, in the middle of summer, people in our office have felt a little too chilly under an A/C vent and actually turned the HEATER on - when it's almost 100 outside.
steve
Oh, you're not stuck, you're just unable to let go of the onion rings.
Stephen got it in one. Moderators (like an earth berm wall) evens things out. I've even seen house designs that use phase-changing salts (in underground tanks) to store heat/cold to lessen/reverse the cycle. As for the humidity. Remember cool air carries less humidity than hot air.
The nice thing about all these approaches is that they address one part of the equation that we need to solve if we're going to reduce our dependency on foreign fuel sources.
Though they were presented as one idea, really either of the two suggestions should help:
1) Pre-cool your office in the morning when energy is more available (and cheaper)
2) Tolerate a higher temperature in the afternoon
Note that even though they didn't emphasize it, they were proposing #2 as well when they said to turn up the thermostat up to 78 degrees (from 74). So, when the precooling runs out you let the temperature rise past where you'd really want it to be.
sHi
You could just do the radical thing. Educate people to turn off lights when they leave, turn off computer monitors, drive cars instead of SUVS, turn things off when they don't use them.
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Too drunk to invent somehing more funny...
Indirect/Direct two stage evaporative AC system coming to market soon:9 8-022-0.html
http://www.oasysairconditioner.com/
background:
http://energy.ca.gov/pier/buildings/projects/500-
Cool features: Runs off 120VAC, pulls between 100 and 500watts while cooling up to 3.5 tons. Automatic variable speed fan motor runs off AC and DC automatically; you can hook up some solar panels and it will blend them without an inverter.
I have been watching this for nearly a year, and it's finally coming to market-- I should be getting my unit in march for $1800. Yes, it is evaporative but it should maintain humidity of around 40-50% indoors, which is actually the recommended levels for people and computers, furniture, etc.
Despite being evaporative technology, it would work fine during monsoon here in AZ, since it can achieve sub-dew point temperatures...
I was thinking if there would be some device that could "store" the cold (like storing the heat but viceversa) of the office buildings at night, and release that cold during peak hours...
Perhaps we could use water containers with pipes connected to the air conditioning or something. Who knows...
Air conditioning (and heating) is most efficient at high heat differences - cooling when already cool is much less efficient that cooling when hot (cooling from 90 to 60 is much less than 30 times cooling from 61 to 60). So pre-cooling could be much worse in terms of total energy usage than longer cycles of letting it heat up a lot, cooling, repeat.
Call me crazy, but when the link is for "a control algorithm," I expect the link to actually point to the algorithm and NOT to an article talking about it. Both are useful, but please label links correctly.
"Nature doesn't care how smart you are. You can still be wrong." - Richard Feynman
Nah, you're not really a Bush-supporting troll hoping to incite flames from other Bush-supporters. Not at all.
In the place I used to work, the girl that had the office next to me happened to have the thermostat for that part of the building. Unfortunately she tended to feel the cold more than most, and in the heat of the Colorado summer had to use a space heater to offset the air-conditioning.
Of course the thermostat then registered that her office was warmer than it should have been and cranked up the A/C. The net effect for me is that my office would get colder and colder.
I work in an office with about fifteen other employees. Last year we quit using the heater in the winter (we're in California). Instead, the company gave us each a wool coat, beanies, and driving gloves (I shit you not). After about a week we stopped complaining and instead became more acclimated to colder weather.
Now I no longer use the heater in my own home, and I find I can more easily adjust to varying temperatures. The company has saved a lot in electricity bills, and we were uncomfortable for a bit, but now I'm saving more at home too. Odd how things work out.
...shade awnings. They work well, and were very common back in the olden days before cheap electricity made cheap air conditioning possible. Now that this is changing, it might be prudent to relook at old solid tech that worked.. In the summer most of the day the sun is high overhead, high enough so that the awnings make the window shady, hence, little direct thermal gain. In the winter, the sun is lower, it comes in under the awning, you get solar thermal gain then, which you want then. The other nifty advantage is you can use your windows. Passive heated solar houses work this way, the south side of the house has a steep overhang and is mostly glassed in. Winter=warmer, summer in the shade= cooler. Works great, no moving parts and less "bunker" closed in no windows claustrophobia action.
Relative Humidity is just that - relative to the temperature. 100% morning RH could mean 40% afternoon RH. Get the morning's wet bulb reading - it will tell you how humid the entire day will be.
I had an idea to generate electricity from the energy of footsteps in hallways and staircases. I know it's not impossible, but I'm wondering - is it feasible?
could it be?
"I have been watching this for nearly a year, and it's finally coming to market-- I should be getting my unit in march for $1800. Yes, it is evaporative but it should maintain humidity of around 40-50% indoors, which is actually the recommended levels for people and computers, furniture, etc."
In other words it will deplete the fresh water supply faster.
the real obvious stuff like having uber-effective insulation, double pane windows, electricity generating solar panels on the building roof, hot water heating panels on the roof, blinds on the windows, ect - you know, all that old-school stuff people weather proofed their houses with before /. was invented (not to knock slashdot, but people seem to think you cant solve things with a decent amount of construction materials, it has to use dual PSU's, ten fans, run embedded linux, and have flashing neon lights).
Then again, maybe I'm just being idealistic about contracters not cutting as many corners they can to save a few bucks here and there...
According to Jevson paradox the saved energy will be used up elsewhere. It can even result in more energy usage.
Government cannot make man richer, but it can make him poorer. - Ludwig von Mises
I'm sick of Rebublicans pissing and shitting on our poor, elderly, and smart people.
If Bush and the Republicans are as bad as you say, how does it make you feel that you weren't smart enough to defeat them?
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
even in places like central australia the water used is less valuable than the electricity required to run a normal air conditioner. Anywhere that people live will need far more potable water than such an airconditioner will use. (Having said that, most commercial designs dump lots of excess water down the drain rather than using it for irrigation or toilet flushing)
this might be news in Buffalo, NY, or Deluth, MN......California- who cares?
Down With Slashdot BETA!!! I've been around the corner and seen the oliphant; you can only abuse me from your perspecti
When I rush into the office from walking outside, I'm always hot and strip off sweaters and open the windows for a bit.
Once I settle down obendiently at my assigned workstation for a few hours, I'm ready to put the sweater back on.
I think starting the day with a freezing building and gradually letting it warm up sounds nice.
Make all of the staff turn off their computers at night. Rather than having 10, 20, 30, 100+ computers and their monitors whirring away doing absolutely nothing at all. Simple I know, but it's amazing that practically no company insists on it. Perhaps it needs their local government to impose some kind of "out of hours" energy tax on them to encourage them.
yay, so we lose, you win
and we forget to talk about energy. you do a little dance...
so we ALL LOSE EVEN YOU (well our kids)
I see constantly people leave their computers on at work; hundreds of people who are not running server software on them, and who have no reason of having the computer run 24 7. Of those maybe 60 people who do have servers running, everyone seems to leave only the server running, and have the screens black. Thus hundreds of CRT displays on all days around, for being used 8 hours a day. I see lights on in all building even at 2 AM, when the last of the workers have gone home by 10 PM (after last of them having finished their work by 8,30 PM). Sometimes I wonder how much energy running all those computers and especially the CRT monitors 24 7 costs. If you have maybe 1200 people working, and at least 60 % of them are using 2 computers on the same time... and how much it would save if the lights were not on in all the building 24 7 as well. And then I remember they don't really care. Employing the 1200+ people is the major cost, then comes the international telecom. If they would save a few thousand $, I don't think that they would really care at all.
This system will reduce lighting energy consumption by 2/3 in most places. You save a LOT by having only the lights on that need to be on and allowing people to dim thier own lights (most people turn the lights down). Combined with the other strategies most buildings really can use about 1/3 of what they typically do. Disclosure: I work for those guys. :)
the condensing outdoor unit standing in the burning ... ...
mid-day sun and don't you just love the outdoor
consing unit standing like 1 inch from the wall, when
acctually positining it 90 degrees to the wall would
give much better airflow and on a windy day even
near "free" condensing? tsh-tsh-tsh
and maybe you have noticed that really cold drinkable
water coming from the indoor unit? well why not
just let THAT flow over the cooling ribs of the
outdoor condensing unit? nevermind then
I must have missed something. Is it the Republicans who want to keep stripping the poor of their dignity by enabling them to survive solely on the government's tit? Is it the Republicans who don't want to strip the country of the ridiculous slush-fund that social security has become? Is it the Republicans who think the average citizen is too dim-witted to manage his or her own retirement dollars? And these intelligentsia you speak of - are they all hiding out on Democratic Underground or busy plotting how to eliminate Wal-Mart so lower income people will no longer be able to take advantage of low-priced goods and less populous areas will experience a drop in the number of available jobs? I just have a couple of other questions for you. Why do you hate a strong economy, and why do you want an old-Europe styled nanny state which is on the brink of disaster as they try to figure out who among their already overtaxed population is going to pay to support their aging population?
Is 70 too cold? Damn straight if it is 95 outside. As one of the suffering first-world cube workers who has regularly worn a wool sweater in July, sneaked in an incandescent desk lamp to occasionally warm the keyboarding fingers and gotten on his chair to plug the overhead air vent with paper towels, I would say the corporate fascination with air conditioning is highly disfunctional. Just fix the attitude and the resources problem is partially solved. I realize it puts me squarely in the "want to solve the energy crisis, quit driving SUVs" crowd, but, hey, there is something to be said for rational realism.
A company wants to talk about climate and productivity, I would be fascinated to learn whether there has been a study of office climate and summer illness. From my experience, I would really like to see a 10 degree indoor/outdoor difference below 100 degrees ouside, 15-20 degrees for 100s, 100 and teens. Who ever got heat stroke at a dehumidified 85-90? But I sure know people who have gotten summer pneumonia at 70. Stupid, stupid, stupid. Maybe we need a lawsuit where somebody dies of summer pneumonia and the surviving family sues the company for inficting it on him before business will get out of their weird rut of "the more we refrigerate our employees the better".
Honewell Chronotherm IV. http://www.honeywell-thermostat.com/honeywell/t860 2-thermostat.htm It adapts to the temperature patterns to start heating or cooling at the optimum time to maintain a steady temperature.
The cold blooded ladies in my office will run their foot heaters even if the temperature is 75 degrees F, counteracting any savings granted by using smart cooling techniques. They are also very good about killing hard drives with those blasted heaters.
+Interesting, +Informative
-kgj
-kgj
googled the hell out of it and found no complaints by buildings about temperature go figure...
You mean the ones you want aborted? Yes they will lose their lives alright.
Long story short, the Democrats have some issues that I agree with. The problem is that they are such hard liners on the other issues, that I can't support them.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
If you are curious enough to read the report, they mention the water usage. Making electricity uses water too, especially from the increased surface area in damming rivers... Thus, the evaporative cooler doesn't actually use a LOT more water than conventional compressor systems... and a large part of the water used is actually discharged and reclaimable as irrigation water for a garden, etc...
Don't feed the trolls. Especially not by trolling.