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Well, For those of us who only have time to go shooting on Sundays (Yeah, I know, probably not many of us...) the Lee Kay center will now be closed on Sundays due to the whole 4-day work week business.

I knew that cockeyed plan was gonna affect me in some way... dangit!
 

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Oooo.... Let's reduce our CO2 emissions by 20%!!!! Bullsnot. Doesn't anyone know that CO2 is not a dangerous gas? Enivrowackos :disgusted:

They say in the article that since people won't be at work, they don't need to heat/cool the building and all the computers and lights will be off. First off, will they really turn off the AC and heaters when nobody is there? Doubtful. And if they do, then what happens come Monday? They have to run the air constantly for HOURS to get it back to the comfort level - now THAT is a waste of energy. And when was the last time you were in an office where people actually turned off their computers as opposed to just turning off the monitor or letting it go to screensaver? I also doubt that ALL the computers will be off from Thursday night to Monday morning. To me, this looks like another half-brained cooky ploy to make the state APPEAR that it is somehow helping. Even if the idea is good (which I am not so sure of), the idea that it will actually do anything positive for the environment is doubtful.

P.S. I love how they estimate that this plan will save around 20% on energy usage... where'd they get that number from? Oh wait... 1 day off in 5 is...um... 20%! - Wow! That's REALLY difficult math... :roll:
 

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They say in the article that since people won't be at work, they don't need to heat/cool the building and all the computers and lights will be off. First off, will they really turn off the AC and heaters when nobody is there? Doubtful.
I just wanted to say first off I think that sucks. I saw the sign there on the door the other day. Luckily I only go during the week as I work close by. However as far as them turning off the AC when people are not there is 100% true. My wife and I have been taking some foster care classes in the evening and due to the whole "energy saving" crap, they shut down the AC just before we get there. Also we used to shut down my work on Fridays and it saved the company about $50,000 a month in utility savings. I see benefit in the saving of money in this effort, but thats about all.
 

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Turning off the AC when the workers are not there is not going to save energy. All it does it make the system work harder and actually use more when they restart it on the Monday and it has to play catchup. Once again all we get is badly thought out lip service to give the appearance of doing something. If they want to do something to help out with an energy crisis and "save the environment" lets get some breeder reactors built so we can actually make use of all of that nuclear "waste" (most of which is still between 90 and 95% useful).
 

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jimtheguern said:
Turning off the AC when the workers are not there is not going to save energy. All it does it make the system work harder and actually use more when they restart it on the Monday and it has to play catchup. Once again all we get is badly thought out lip service to give the appearance of doing something. If they want to do something to help out with an energy crisis and "save the environment" lets get some breeder reactors built so we can actually make use of all of that nuclear "waste" (most of which is still between 90 and 95% useful).
:agree: We waste so much by NOT utilizing all the energy sources we ALREADY have. Instead we feel we to create MORE energy, when in effect we just need to better use that which we have (can anyone say "Offshore Drilling"?).
 

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jimtheguern said:
Turning off the AC when the workers are not there is not going to save energy. All it does it make the system work harder and actually use more when they restart it on the Monday and it has to play catchup.
That's not correct.

It is true that the system will have a big job on Monday to bring the temperature down, but it takes less energy to bring it back down than it does to keep it down. Heat transfer is directly proportional to temperature difference, so maintaining a low temperature ensures continual transfer of heat in from the outside, heat that has to be pumped back out. Allowing the temperature to rise inside slows the rate of transfer and reduces the total amount that has to be removed.

Think of it like a kiddie pool with a small hole midway up the side. Suppose the pool holds 200 gallons and the hole is exactly halfway up, so after 100 gallons leaks out, no more is lost. Suppose the leak is at a constant rate of one gallon per hour, so that after 100 hours, it stops leaking, and suppose that you have a party in 200 hours and you need the pool to be full then. If you keep it full the whole time, you'll continue losing one gallon per hour for 200 hours, so you'll have to put 200 gallons in. If you let it drain until it stops leaking, then fill it back up just before the party, you only need to put 100 gallons in.

It's actually a little more complex than that, because a real-world leak doesn't flow at a constant rate. As the water level drops, the water pressure at the level of the hole decreases and the leak slows. So even if the party is close enough that you'll never reach the non-leak level, you're STILL better off waiting and filling it all at once, because that way most of the time you'll have a slower leak than if you kept the pool full.

Heat transfer works the same way. By shutting off the AC, you allow the building temperature to rise, and that slows the rate at which more heat enters the interior. By keeping the building cool, you keep the heat transfer rate high -- and every calorie/BTU of heat that flows into the building has to be pumped back out.

If you're interested in how this works, mathematically, it's just simple exponential decay. As usual, the wikipedia article is quite good.

jimtheguern said:
If they want to do something to help out with an energy crisis and "save the environment" lets get some breeder reactors built so we can actually make use of all of that nuclear "waste" (most of which is still between 90 and 95% useful).
Absolutely correct -- except that the useful waste is more like 98%. Within a few years we could drastically reduce our consumption of coal if we'd address the POLITICAL problems holding us back from large-scale nuclear power production. The engineering problems are long-solved, if we'd exercise the political will to put the solutions into effect. The political opposition to breeder reactors is the biggest problem.
 

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Hey the Gov has gone green. Just like his hero Arny. So what else can I say good about him :raisedbrow:
 

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I work for the U of U and will not be going to a four day work week. Needless to say though, I certainly hope that with the closure of the majority of public buildings on Fridays I may actually be able to drive the 15 minute drive to work in 15 minutes! That will save me on my fuel costs. The frustrations from idiot drivers, people driving 25 in a 40 etc will be drastically reduced, therefore I will arrive at work happier with less frustration and my day will be better. This saves me a lot! I will also be saving fuel because I won't be in my car for half an hour to an hour. This translates to less overall emissions, less fuel waste etc. Maybe I can now afford a new necklace for my wife.....hmmm This could be helpful! O, and when I arrive home at night on Fridays my wife will be happier because I will be happier and Lord knows, keeping your wife happy is the most important thing in life! :D
 

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As far as lighting goes (ignoring heating/cooling for now) I still don't even see how they could claim 20% energy savings because they still work 40 hours a week, right? This means they will still need lighting for at LEAST as many hours as before the change. If you think about it, they will actually need more lighting now because days that they are there, they will be there for longer hours, which means they will spend more hours there after dark, and hence require more lighting.
 

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In addition to Swil's excellent points about how turning off the AC *DOES* in fact save money...

1) It must be remembered that while turning off the AC for an hour or two may in fact be less energy-efficient than having just left it on in the first place, it is still much much more efficient to turn off the AC for a year if you don't need it rather than leave it on so the building is ready the day you step foot back in it... yes, both are extreme examples, but to make the point: efficiency is all about math... it's about determine, precisely, when that "cut off" period is... or where the thermal-wall is, so to speak. Of course, we can't all determine where that line is in every situation easily enough to warrant doing that math... but the math is still there. Simply saying that turning off the AC is less efficient than leaving it on is a very fallacious argument. The math is the truth... and eventually it shows that AT SOME POINT it is more efficient to turn the thing off. I think ANY REASONABLE ESTIMATE would show that 3 days is more than sufficient to reach that line to warrant turning it off. In fact, a single day is plenty long enough considering that the building will cool off naturally through the night if allowed to.

2) Just b/c we have all seen examples of people NOT turning off lights, computers, etc doesn't mean we shouldn't support measures to conserve energy on the principal of it (and work to ensure these things are turned off too!) -- rather than condemn the whole thing from the start. I can show you "lawfully armed citizens" who shot innocent people too -- does that mean I should immediately count you as suspect and take away your arms just b/c I saw some other guy not do what he should have done??? Obviously not. Principles should rule, not specific people.

3) In addition to #2, perhaps we should ask that an addition to this new policy be adopted... maybe even made law, I don't know... but something that appoints someone as the "Energy Czar" of each building... that person would be responsible for getting automated power-off solutions installed when available and economical and they would be responsible for conducting training and "spot checks" to ensure the 4-day policy amounts to substantial change.

4) Additionally, a few fairly inexpensive automated tools can be easily implemented so that a few of the buildings windows be opened and the AC is cut to allow for natural ventilation during the 3-day break... ensuring that the AC when it kicks back on on Monday morning at 6AM won't actually have to be under a load.

Efficiency *DOES* work... for anyone who thinks it doesn't, I dare to compare my utility bills against yours! :mrgreen:
 

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bane said:
It must be remembered that while turning off the AC for an hour or two may in fact be less energy-efficient than having just left it on in the first place
It's not. Turning it off for a while may not save you anything appreciable, but it definitely won't cost you more.

I like the four-day week mostly because it makes it easier to go to the DMV, or whatever, without taking time off work. Not an issue for me, but I know a lot of people who will be helped by the extended hours.
 

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swillden said:
bane said:
It must be remembered that while turning off the AC for an hour or two may in fact be less energy-efficient than having just left it on in the first place
It's not. Turning it off for a while may not save you anything appreciable, but it definitely won't cost you more.
Unless I misunderstood what you were saying... efficiency does in fact go the other way... there IS a point where leaving it on is more efficient -- that is, unless you are not going to turn it on again until you go past the point of the "thermal-wall". I realize the two are different, but to convey a point, consider the engine of a car. Turning it on an off at every single light you stop at is more in-efficient than leaving it running b/c it takes more gas just to re-start the car than it would have done to idle for 30 seconds. But the reverse holds true if you are stopped for 2 or 3 minutes because that amount of idling uses more gas than what you will spend to turn the car back on. Granted, AC units don't have the same requirement of "start-energy" but the concept is the same.
 

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bane said:
Unless I misunderstood what you were saying... efficiency does in fact go the other way... there IS a point where leaving it on is more efficient -- that is, unless you are not going to turn it on again until you go past the point of the "thermal-wall".
You misunderstood me. Probably because my swimming pool analogy wasn't great. Actually, the analogy is fine, but I intentionally misstated it to simplify it a little, then I tried to clarify by pointing out how it was misstated. Sounds like it just created confusion.

There isn't a "thermal wall", really. In fact, if the exterior temperature were constant it'd be a kind of Zeno's Arrow situation... the interior temperature gets closer and closer to the outside temperature, but never quite gets there. The closer it gets the slower the heat flows. Any time you allow the inside temperature to rise a little closer to the outside temperature, you slow the rate at which heat is flowing in. By slowing the rate at which it enters, you reduce the amount you have to pump back out.

You pointed out the reason why the comparison with the car engine doesn't hold: internal combustion engines consume more fuel while starting than while idling. AFAIK, there is no comparable startup cost for an AC. Maybe the energy to spin up heavy fan blades? Most of them are very lightweight, though, so I don't think that amounts to anything significant. Further, AC units are MORE efficient when the temperatures of their heat exchangers are near equilibrium with the surrounding air. As the hot side of the cooling loop heats up, it takes more power to compress the gas, and as the cool side gets colder the expanding gas absorbs less heat.

It seems likely that variable-speed units might be more efficient when running on low to maintain a temperature than when they're cranked up to high in order to cool the building quickly. If that's the case, though, the answer is to turn the AC back on a few hours before everyone arrives, so you have time to cool the building with the AC running on low. Turn it on Sunday night, to take advantage of cooler outside temperatures.
 

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Bane, I think Swillden is saying that there is no such thermal wall in this situation.

I think that swillden's pool analogy more closely resembles the situation than the car analogy. Not saying Bane is wrong... I don't really know. I'm just saying I'm personally more convinced by swillden's analogy and argument. :)

Bane, I would like to challenge the assumption that turning the car off for a few seconds at a stop light, and then back on again, actually takes more gasoline than just leaving it running. How can you back up this assertion? Again, not saying you're wrong, because I really don't know. I would just like more facts.

I thought the reason that most people don't turn there car off at stop lights (besides the inconvenience) is because of the extra wear on the engine, not because it saves gas to leave it on....... :dunno:

Edit: this post was written before the previous post (by swillden) was posted. So some of it's out of date now :(
 

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swillden said:
bane said:
Unless I misunderstood what you were saying... efficiency does in fact go the other way... there IS a point where leaving it on is more efficient -- that is, unless you are not going to turn it on again until you go past the point of the "thermal-wall".
You misunderstood me. Probably because my swimming pool analogy wasn't great. Actually, the analogy is fine, but I intentionally misstated it to simplify it a little, then I tried to clarify by pointing out how it was misstated. Sounds like it just created confusion.

There isn't a "thermal wall", really. In fact, if the exterior temperature were constant it'd be a kind of Zeno's Arrow situation... the interior temperature gets closer and closer to the outside temperature, but never quite gets there. The closer it gets the slower the heat flows. Any time you allow the inside temperature to rise a little closer to the outside temperature, you slow the rate at which heat is flowing in. By slowing the rate at which it enters, you reduce the amount you have to pump back out.

You pointed out the reason why the comparison with the car engine doesn't hold: internal combustion engines consume more fuel while starting than while idling. AFAIK, there is no comparable startup cost for an AC. Maybe the energy to spin up heavy fan blades? Most of them are very lightweight, though, so I don't think that amounts to anything significant. Further, AC units are MORE efficient when the temperatures of their heat exchangers are near equilibrium with the surrounding air. As the hot side of the cooling loop heats up, it takes more power to compress the gas, and as the cool side gets colder the expanding gas absorbs less heat.

It seems likely that variable-speed units might be more efficient when running on low to maintain a temperature than when they're cranked up to high in order to cool the building quickly. If that's the case, though, the answer is to turn the AC back on a few hours before everyone arrives, so you have time to cool the building with the AC running on low. Turn it on Sunday night, to take advantage of cooler outside temperatures.
:thijack:

Tarzan
 

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Y'know, I could swear that I had read differently on Rocky Mountain Power's website some time back but I can't find that info. anymore. My understanding was that in order to remove all the old trapped moisture it took a lot more work on the part of the compressor to "catch up".

However, I did find this link which offered some very good argumentation supporting your position so perhaps I am swayed a bit b/c though for some reason it didn't "click" when I read it here, it finally did when I read it from the other site... here it is if you are curious: http://www.answerbag.com/q_view/23022

Essentially what they are saying is that if you leave the house for the day and your house absorbs 'x' amount of heat to be NEAR the outside temp it will stop absorbing heat and just sort of "sit there" all day not getting hotter. When you come home it removes that 'x' amount of heat ONLY ONCE. But if you set your A/C to effectively remove, say 20% of 'x' amount of heat it will remove that amount of heat in the first hour and then b/c the temp in the house is so much cooler than the outside it will act like a 'heat magnet' and soon the temp in the house will be right back up again so that 20% of 'x' has to be removed yet again... and over and over all day long... easily adding up to much more than just the 'x' one time when you get home. It makes sense.

OTOH I could've sworn that RMP's site suggested setting your thermostat with a 3-5 degree variance so that when your cooler clicks on it stays on longer b/c your cooler is more efficient running for longer times than shorter ones. For example, you should set your thermo so that the cooler clicks on at, say, 83, and clicks off at 78. So I'm not convinced in your argument yet, even though it makes sense from the perspective of being gone all day long -- I'm not sure it makes sense when you are talking shorter periods of time, like over the course of an hour or two.

If I get a chance I'll dig some more and see if I can find the reference I'm referring to.
 

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@eddified: Man I suck. :lol3:

OK so not only did I use an analogy that wasn't highly analogous -- I didn't mean to infer they were, though. All I was trying to do was demonstrate that efficiency goes both ways -- it's not a one-way process. But my analogy was a poor one and led to more confusion than it was worth. Sorry about that.

Then I compounded the problem by relying on old info. Older cars actually *DID* consume more fuel starting than they would idling for a short period of time. The old recommendation was if you were going to be idling for more than a minute or two, turn it off. Otherwise, leave it on. This was because not only did the engine require a large boost of fuel to start but it also required a very large draw on the battery to get it to turn over... which needed more fuel to re-charge the battery. But apparently this is out-dated info (I wasn't aware that it was). Now the critical time is around 10 seconds. But even though it's now 10 seconds as opposed to 1-2 minutes, the example still demonstrates the point I was trying to make: that efficiency goes in both directions, not just one. If you are going to idle for more than 10 seconds, turn off the car (not recommended in traffic, of course) -- if it's going to be less than 10 seconds you'll be wasting more fuel by turning it off. Yeah, it's a small difference, but it shows the point.

In the end I wasn't really arguing AGAINST Swil's point. With respect to the over-arching theme we were discussing (Lee Kay's closing over 3 days and whether or not shutting down their A/C will actually save money), I agreed completely with him. The only caveat I threw in there was that the efficiency several people were referring to (that it is sometimes more efficient to leave something running rather than turn it off) is true but ONLY under certain relatively short periods of time.

@Swill: OK, so I didn't find the original Rocky Mountain Power reference that I drew my A/C conclusions from but I found another one that says the same thing: "Don’t turn off the air conditioner when you’re away from the house for the day. When away from home for several hours, set the thermostat at 85 degrees. It takes less electricity to maintain that temperature than it does to cool down the house when the temperature is allowed to rise higher because the air conditioner has been off all day." I found a few other similar references elsewhere but thought the RMP one was more authoritative since it's local.

Again, I'm not at all arguing that you won't save money by turning the A/C off over extended periods of time (from this RMP press-release, it sounds like 1 day is a good target). But turning it off for just a few hours will cost more to start back up than it would have to just raise the thermo a bit and then lower it back down when needed. I always leave the thermo on but set a little high during the day and turn it off at night to get the free outdoor air. Running it all night would be stupid (most nights) but turning it off all day while at work is a little counter-productive too b/c the thing has to run for hours in the evening just to remove all the old humid air that got trapped inside. Removing heat is one thing -- removing the moisture in the air is another, and it's takes the AC a lot longer to do that.

Regardless, we are arguing the same thing in relation to shutting down gov't buildings over the 3-day weekends. Shutting down the AC for 3 days, without a doubt, conserves. Especially if a few windows can be opened (or vents) over the weekend so the building is roughly the same temp as the outside on early Monday morning when the windows get shut and the AC gets turned back on. Better yet, a few automated windows, vents, and fans would allow them to shut the AC off every single night and save even more money.
 
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