"2. Chinese scientists miss the poor stitch job and proclaim they found a new crater."
Which makes them look like idiots. Their first reaction should have been "Huh? That can't be right" and rechecking the data. And if they did so and still didn't catch the mistake, they are even bigger idiots.
"The original article says and suggests nothing about the photo being "doctored", it's simply a mistake that scientists make all the time."
You mean the mistake of incorrectly stitching the photos, or the mistake about yelling "Hey, we found a new crater the American photos don't show" instead of "WTF - this can't be right".
Yes both are mistakes, but one is a lot more meaningful than the other.
"What will be the duration of the current "armed conflict"? "
Welcome to the problem with the Geneva Conventions - they were written for a different kind of war.
If I had to put an end date to it, I'd say that the "conflict" is ended when the nation from which they were taken is in a position to restrain them from further combat if returned. In specific, send them back to Afghanistan when the government there can guarantee they won't be wielding an AK any more - Taliban eradicated, and control of the whole country. This is in the spirit of the original conventions - soldiers are returned when the war is over and they won't fight anymore.
For insight, look up the concept of "parole" as it pertains to war - POW's can be released if they promise to not engage in combat against the capturing country. If they do, they are not subject to the GC's anymore - at the time the GC's were written, that was understood to mean "shot out of hand for being a saboteur/spy". The idea is that, once a soldier is captured, he should cease to be a threat.
India is a former British colony with about a bajillion different languages, so English is the lingua franca there - lots of folks learn english not to get a job in a call center, but because it's pretty much required to exist and function.
Mexico is a former Spanish colony where the native languages were pretty much wiped out. One can get along just fine in Mexico, or anywhere in Central and South America on spanish alone. Indeed, I sometimes think it is a point of pride for some immigrants to NOT learn english when they live in the US.
I don't disagree that it would help Mexico immensely for such a program to exist, but comparing to India is a red herring.
I have 2. Actually, now that they are getting older (12 & 7) I'm getting more brain practice in - it's real work trying to keep one step ahead of the precocious little bastards!
"Its like we *chose* to piss off the middle east and make them go crazy and hate us. You don't 'fix' bee nests by hitting them with rocks."
You might want to pick a better analogy. Most of us either burn them out or use spray and kill the whole colony. As attractive as eradicating huge swaths of the Middle East and Southern Asia may be, it's impractical and unnecesary
No, really - I live here, and this is just the latest. This is part of a plan to cover a $1B+ gap in the budget. The new Governor proposed raising taxes to cover the gap AND increasing spending on various social programs. Spending cuts? Not even on the radar.
Even better is that 90%+ of the tax burden falls on 1 county (albeit one of the richest ones in the country). And the county delegates to the legislature - you know, the ones who represent the citizens - offered token resistance then rolled over and took it "for the good of the Democrats...errr, the State".
My guess is that ATT is betting that a large percentage of the teleworkers will either resign, or come back with such bad attitudes that they will be fired "for cause" shortly after their return.
The reality is that, in the current business environment, it is better for your career to be mildly competent but in plain sight that extremely competent but hidden at home.
"More to the point, what on earth does it being carried or not carried have to do with what the game is rated? Either it meets the standard for 'M', without exceeding it and going beyond into 'AO', or it does not."
I think you've inadvertantly hit on the fundamental flaw with the rating system.
In the rating system, "Adults Only" means that it may only be sold to adults - 18 and over. "Mature" is given to content that is only for those people, children included, who are "mature" enough to handle it - rought guide, 17 and over. Now, in teh vernacular, "mature" MEANS "adult".
So why is there 2 different ratings that have basically the same meaning? It's the difference between sex and violence. Regardless of what is written in the ratings descriptions, the intent of "M" is to denote violence, and "AO" is to denote sex. This was to address the American dichotomy between how we treat sex and violence in the media, and Congress bought into it. And at the time, it was no big deal - the violence was "cartoony" anyway, so it could be safely ignored.
Fast forward via Moore's Law, and now videogame violence can be made to seem VERY realistic. So now, when Jerry dropd teh anvil on Tom's head, we see the brains splatter in all their polygonally rendered and physics engine derived glory, and folks are going "WTF - this wasn't the violence I agreed to!"
Congress has a long history of doing this shit, from Jack Valenti to Tipper Gore. Is anyone here surprised at this, or at how our schizophrenic views of sex and violence are ultimately irreconcileable?
I never "alluded" to anything - I was replying to 2 false aspects of your comment regarding "captured soldiers" and that our own soldiers will be subject to torture as a result of their actions.
1) The definition of "soldier" is in the Geneva Conventions, and the people setting off IED's, blowing themselves up, and shooting at civilians and soldiers in Iraq do not qualify. You might want to actually read the Geneva conventions before invoking them.
2) Your warning about the possibility of US soldiers being subject to torture in the future is a red herring - they are subject to torture NOW, and have been subject to torture by those they are fighting for many years. The whole world saw that US soldiers' bodies could be dragged through the streets in Somalia - from then on, the GC's haven't aplied to how US soldiers have been treated.
There are plenty of reasons why torture is wrong - you just didn't give any of them.
"unaffiliated lone terrorist who commits a murder"
Huh? IIRC, Daniel Pearl was captured and held by a group affiliated with an international terrorist organization, was stabbed by all the members of that group, and had his head sawed off while being videotaped. Then that tape was delivered through clandesine means to news organizations. I missed the "unaffiliated lone terrorist" part of that.
"This also applies to torture and other interogation techniques like "water boarding" for captured soldiers. In the future our military personal should expect to have the same treatment that we are giving others with water boarding, etc."
Name a single "captured soldier" that was subject to water boarding. A single one. Can't do it, can you? Insurgents, who are, by definition, NOT soldiers, have been subject to these techniques. Uniformed soldiers of the Iraqi army were treated very well, with the exception of being paraded in front of cameras - and it was caught and stopped.
As for "expect to have the same treatment", our soldiers fully expect to be tortured, burned, executed, beheaded (not necessarily in that order) and have their headless bodies dumped in the river. That all started long before any allegations of torture were levelled against the US.
Water boarding and other similar techniques are wrong, and should never have been authorized, but the local insurgents and international terrorist organizations have NEVER played by the rules of the Geneva convention. Indeed, that is their whole modus operandi - targetting civilians in the full knowledge that the military cannot effectively respond in a civilian environment.
I'm telling ya', when we do finally get there we are going to find Beagle 2 with no wheels, the antenna busted off (used to smash open the camera lenses), and strange graffiti that translates to "All your rover are belong to us!" in Martian.
I'm a mechanical engineer, and I demand the construction of a full scale Babbage engine, simply for bragging rights....grumble grumble...fucking EE's think the sun shines out their asses...grumble...
"but our HVAC consultants can't answer because they don't do server rooms, "
and
"We don't need someone to tell us if we need 2.5million BTUs vs. 4.5million BTUs, we need just a general figure of 30,000 BTUs vs. 300,000 BTUs."
Apparently, your consultants think you DO need someone to tell you that, because it is outside their area of expertise.
And it may not be the core of your business, but that doesn't mean it's not *critical* to your business. See what happens to your deadlines because your file servers are down because the AC units were sized on the back of an envelope.
Your contractors need the RIGHT answer; are you sure it's the one you get from Slashdot?
I hate appeals to authority, but this is getting old.
I have a degree in Mechanical Engineering, including a course in HVAC design and a number of them in thermodynamics. Most of my career has been in building construction for General Contractors and Building Owners, dealing specifically with HVAC system installation and troubleshooting in everything from commercial, industrial, laboratory, and data centers.
You are purposely misreading my statements and attributing meanings that do not fit reality, much less what I was saying.
In my first post, I was talking about free cooling, which is bringing air directly in to a space because it is already cooled. I also responded to your comment "dehumidification only shouldn't necessarily require running a coil with the 20-30 degree temperature gap that the AC coil requires, thus saving some energy.", because it is untrue, and I gave reasons.
You turned it into heat exchangers, and your rebuttal to my comments on dehumidification violate physical laws, and I pointed that out.
Now, it's ALL about dehumidification "This is a brutally stupid statement. Dehumidifiers run the outside air over the cool coils to dehumidify it, then over the hot coils to re-heat it."
No shit - that's what I said before regarding residential units.
"THAT is the heat exchange."
Not really - it's a refrigeration cycle. It uses heat exchangers (refrigerant to air) as components, but the net is heat INPUT into the space.
"You'd be an idiot to run it over the hot coils first, that's the exact opposite of what you need."
And since I was addressing your comments regarding residential outside air heat exchangers, I poined out how stupid that would be. Somehow, when I was talking about outside air heat exchangers, you thought I was talking about dehumidifiers.
"Why you're confusing the simple operation of a dehumidifier with residential heat exchangers, I haven't a clue."
I don't think I'm the one who is confused here. Do you have any qualifications at all to be saying the things you are saying?
I didn't even address these beauties:
"No, what you do is install a second fan."
Regarding the second fan, what do you get? More airflow? If the duct size is the same, your pressure goes way up, and your velocity. So you are burning the same amount of energy - actually more, because large fans are typically more efficient than small, what with motor losses, etc.
"It's a patently ridiculous claim, anyhow. If you couldn't blow-in enough cool air from outside, then you couldn't move enough air to/from the AC units.."
Sure about that? In a server room the is typically very little ductwork - a raised floor acts as a plenum, and short return duct go back to the air handler which is in or right next to the room. If you are bringing air in from the outside, unless the room is near an outside wall there is ductwork required to carry the air, sometimes long runs. The ductwork resists air flow and conducts heat into the airstream, so larger fans and cooler air are required. And you want to run this ductwork for that portion of the year when free cooling is feasible? Especially when those same climactic conditions make conventional cooling system much more efficient? What's the ROI on that?
If you are going to troll, at least know SOMETHING about your topic.
Are you stupid? A heat exchanger (btw, not "very common" at all in residential) is the OPPOSITE of free cooling! In free cooling, COLD outside air is brought directly into the space, bypassing the cooling coils. Why? Because the air is cool already.
With a heat exchanger, you are bringing cool air in, and then HEATING IT UP with the waste heat from the exhaust air. Great for saving energy in a residence, when one wants to stay toasty warm - not so great in a data center or office building when there is still a cooling load in winter. So absolutely nothing you said has anything to do with free cooling. Heat exchangers are great for what they do, but free cooling isn't it.
"That's also untrue. The direct, free-flowing heat exchange between hot and cold coils allows dehumidifiers to be much more energy efficient, using typically around 1/3rd as much power for the same volume of air."
True - IF you are using a heat exchanger. But if one is not - lets say, in an office building on a cool spring morning - then you have a problem. You bring in nice 65F air, at 65-70% RH - it's wet. You don't heat it up through a HX, because you need the 65F air to maintain temp setpoint. But now you are dumping a lot of water into the space, and it doesn't *feel* cool. So, you run your cooling coil at, say 50F discharge temp. That is below dewpoint, and it pulls moisture out of the air. But now you are dumping 50F air into the space, so the space temp gets driven down, and you get the nipple effect. So what do you do? REHEAT the air to 65F. Which, BTW, is exactly what home humidifiers do - the discharge air is reheated to a temp greater than the intake air, reflecting the energy added by the electricity. TANSTAAFL.
You can throw a HX in that equation, but it certainly isn't a dumb device - the control logic needs to know when to open the air dampers and close them, so as not to interfere with free cooling.
"As to coil temperature, obviously any temperature will work, to varying degrees of effectiveness. You'll need to provide some numbers to back up your claim. General-purpose dehumidifiers are usually just slightly modified AC units"
Bullshit. The coil temperature MUST be less than the dew point of the air, by the very definition of "dew point". Practically, it needs to be substantially less for the dehumidification to really work. Often, that temp is less than desired for discharge air temp. See above example.
Call me when you've bought a psychrometric chart and a ductulator. There are plenty of design decisions to be made when designing an HVAC system, unfortunately including appeasing owners who think they are design geniuses.
What you and the OP are describing is called "free cooling", a long established principle in HVAC design. It is used in commercial and industrial buildings all the time. The reason that it is not used in residential all that much is that
1) until relatively recently, houses "breathed" quite well on their own due to loose construction. With tightening energy codes and the use of Tyvek and better windows, houses don't have a lot of air exchange through the boundaries, and problems ensue - "stuffiness", moisture, mold, "sick building". Residential construction hasn't thought this through yet - there are some builders who now refuse to use Tyvek due to ventilation (and liability) issues.
2) Controls become an order of magnitude more complicated. Most residential systems are "bang bang" systems - it's on or off based on 1 criteria. To introduce free cooling, you need outside air sensors, dampers, actuators, and a controller a lot more complex than a home t-stat. For most ersidential builders, that's a couple thousand in extra costs that can't be recouped in sale price - most owners just don't care, and when you are building 5000 of the same unit, "most owners" rule.
As for dehumidification, you have it backwards - dehumidification typically required a COLDER coil than necessary for cooling alone, and then you reheat the air. It is horribly inefficient, but sometimes necessary - with a "tight" building, you have to get the moisture out somehow, and supercooling the air inside just isn't a good idea (other than making for lots of erect nipples, that is)
Finally, what makes sense for one situation may not for another - a data center uses orders of magnitude more cooling than a house or common office building. Moving the amount of air necessary to provide that cooling gets really hard - the amount of energy a fan requires increase with the CUBE of the flow required. So to get twice the airflow you use 8x the power. It's the same with pumps, but because the heat capacity of water or glycol is so much greater than that of air, the effects are minimized.
Not exactly - it has more to do with starting the compresor against full high-side pressure. The critical time preiod is "finish to start", not "start to start".
The general rule that I follow in such a situation is HIRE A PROFESSIONAL! There are people who do this stuff all the time, and actually have insurance in case they screw up their calcs - they're called HVAC engineers. Use one.
And please let me know the name of your company so I can sell it's stock short - what the fuck are they doing having someone "specifying" a server room who can't figure the loads?
Part of the problem is that it is a lot easier to move heat via liquid than air. the conventional design uses chillers mounted outside the space to cool a liquid medium/refrigerant, which is then pumped very efficiently to cooling coils in the space (modify for DX coils). the air inside the condityioned space makes a very short trip through the servers, across the room, over the coil, and back out again.
Under your scenario, the AIR is the working medium - it is cooled on the outside, and then moved inside via relatively inefficient fans. And it is a SHITLOAD of air - that means either high volumes (huge ductwork) or high velocity (how do you like working in a wind tunnel?).
Fans on UPS? Are you kidding? How big do you want your UPS to be? Fans suck a LOT of power, especially when you have them doing what you propose.
"as part of the design for the cluster room in our new building I've specified such a system"
You've specified? From your post, it's obvious you aren't an HVAC engineer, so what are your qualifications? Did you do an analysis to see what the real ROI is? Or is it just so obvious to you why years of HVAC design are totally wrong?
Slashdot Mirror
"2. Chinese scientists miss the poor stitch job and proclaim they found a new crater."
Which makes them look like idiots. Their first reaction should have been "Huh? That can't be right" and rechecking the data. And if they did so and still didn't catch the mistake, they are even bigger idiots.
"The original article says and suggests nothing about the photo being "doctored", it's simply a mistake that scientists make all the time."
You mean the mistake of incorrectly stitching the photos, or the mistake about yelling "Hey, we found a new crater the American photos don't show" instead of "WTF - this can't be right".
Yes both are mistakes, but one is a lot more meaningful than the other.
"What will be the duration of the current "armed conflict"? "
Welcome to the problem with the Geneva Conventions - they were written for a different kind of war.
If I had to put an end date to it, I'd say that the "conflict" is ended when the nation from which they were taken is in a position to restrain them from further combat if returned. In specific, send them back to Afghanistan when the government there can guarantee they won't be wielding an AK any more - Taliban eradicated, and control of the whole country. This is in the spirit of the original conventions - soldiers are returned when the war is over and they won't fight anymore.
For insight, look up the concept of "parole" as it pertains to war - POW's can be released if they promise to not engage in combat against the capturing country. If they do, they are not subject to the GC's anymore - at the time the GC's were written, that was understood to mean "shot out of hand for being a saboteur/spy". The idea is that, once a soldier is captured, he should cease to be a threat.
"sucks giant donkey balls"
What's sad is that there is a probably a video in the internet of someone doing just that.
Somewhat diferent situations.
India is a former British colony with about a bajillion different languages, so English is the lingua franca there - lots of folks learn english not to get a job in a call center, but because it's pretty much required to exist and function.
Mexico is a former Spanish colony where the native languages were pretty much wiped out. One can get along just fine in Mexico, or anywhere in Central and South America on spanish alone. Indeed, I sometimes think it is a point of pride for some immigrants to NOT learn english when they live in the US.
I don't disagree that it would help Mexico immensely for such a program to exist, but comparing to India is a red herring.
I have 2. Actually, now that they are getting older (12 & 7) I'm getting more brain practice in - it's real work trying to keep one step ahead of the precocious little bastards!
I am positive that, after 6 years (2 degrees) of drinking and sleep deprivation, I am significantly dumber than I was going in to school.
"Its like we *chose* to piss off the middle east and make them go crazy and hate us. You don't 'fix' bee nests by hitting them with rocks."
You might want to pick a better analogy. Most of us either burn them out or use spray and kill the whole colony. As attractive as eradicating huge swaths of the Middle East and Southern Asia may be, it's impractical and unnecesary
No, really - I live here, and this is just the latest. This is part of a plan to cover a $1B+ gap in the budget. The new Governor proposed raising taxes to cover the gap AND increasing spending on various social programs. Spending cuts? Not even on the radar.
Even better is that 90%+ of the tax burden falls on 1 county (albeit one of the richest ones in the country). And the county delegates to the legislature - you know, the ones who represent the citizens - offered token resistance then rolled over and took it "for the good of the Democrats...errr, the State".
My guess is that ATT is betting that a large percentage of the teleworkers will either resign, or come back with such bad attitudes that they will be fired "for cause" shortly after their return.
The reality is that, in the current business environment, it is better for your career to be mildly competent but in plain sight that extremely competent but hidden at home.
"More to the point, what on earth does it being carried or not carried have to do with what the game is rated? Either it meets the standard for 'M', without exceeding it and going beyond into 'AO', or it does not."
I think you've inadvertantly hit on the fundamental flaw with the rating system.
In the rating system, "Adults Only" means that it may only be sold to adults - 18 and over. "Mature" is given to content that is only for those people, children included, who are "mature" enough to handle it - rought guide, 17 and over. Now, in teh vernacular, "mature" MEANS "adult".
So why is there 2 different ratings that have basically the same meaning? It's the difference between sex and violence. Regardless of what is written in the ratings descriptions, the intent of "M" is to denote violence, and "AO" is to denote sex. This was to address the American dichotomy between how we treat sex and violence in the media, and Congress bought into it. And at the time, it was no big deal - the violence was "cartoony" anyway, so it could be safely ignored.
Fast forward via Moore's Law, and now videogame violence can be made to seem VERY realistic. So now, when Jerry dropd teh anvil on Tom's head, we see the brains splatter in all their polygonally rendered and physics engine derived glory, and folks are going "WTF - this wasn't the violence I agreed to!"
Congress has a long history of doing this shit, from Jack Valenti to Tipper Gore. Is anyone here surprised at this, or at how our schizophrenic views of sex and violence are ultimately irreconcileable?
I never "alluded" to anything - I was replying to 2 false aspects of your comment regarding "captured soldiers" and that our own soldiers will be subject to torture as a result of their actions.
1) The definition of "soldier" is in the Geneva Conventions, and the people setting off IED's, blowing themselves up, and shooting at civilians and soldiers in Iraq do not qualify. You might want to actually read the Geneva conventions before invoking them.
2) Your warning about the possibility of US soldiers being subject to torture in the future is a red herring - they are subject to torture NOW, and have been subject to torture by those they are fighting for many years. The whole world saw that US soldiers' bodies could be dragged through the streets in Somalia - from then on, the GC's haven't aplied to how US soldiers have been treated.
There are plenty of reasons why torture is wrong - you just didn't give any of them.
which would be AWESOME!!!
"unaffiliated lone terrorist who commits a murder"
Huh? IIRC, Daniel Pearl was captured and held by a group affiliated with an international terrorist organization, was stabbed by all the members of that group, and had his head sawed off while being videotaped. Then that tape was delivered through clandesine means to news organizations. I missed the "unaffiliated lone terrorist" part of that.
"This also applies to torture and other interogation techniques like "water boarding" for captured soldiers. In the future our military personal should expect to have the same treatment that we are giving others with water boarding, etc."
Name a single "captured soldier" that was subject to water boarding. A single one. Can't do it, can you? Insurgents, who are, by definition, NOT soldiers, have been subject to these techniques. Uniformed soldiers of the Iraqi army were treated very well, with the exception of being paraded in front of cameras - and it was caught and stopped.
As for "expect to have the same treatment", our soldiers fully expect to be tortured, burned, executed, beheaded (not necessarily in that order) and have their headless bodies dumped in the river. That all started long before any allegations of torture were levelled against the US.
Water boarding and other similar techniques are wrong, and should never have been authorized, but the local insurgents and international terrorist organizations have NEVER played by the rules of the Geneva convention. Indeed, that is their whole modus operandi - targetting civilians in the full knowledge that the military cannot effectively respond in a civilian environment.
I'm telling ya', when we do finally get there we are going to find Beagle 2 with no wheels, the antenna busted off (used to smash open the camera lenses), and strange graffiti that translates to "All your rover are belong to us!" in Martian.
I'm a mechanical engineer, and I demand the construction of a full scale Babbage engine, simply for bragging rights. ...grumble grumble...fucking EE's think the sun shines out their asses...grumble...
"but our HVAC consultants can't answer because they don't do server rooms, "
and
"We don't need someone to tell us if we need 2.5million BTUs vs. 4.5million BTUs, we need just a general figure of 30,000 BTUs vs. 300,000 BTUs."
Apparently, your consultants think you DO need someone to tell you that, because it is outside their area of expertise.
And it may not be the core of your business, but that doesn't mean it's not *critical* to your business. See what happens to your deadlines because your file servers are down because the AC units were sized on the back of an envelope.
Your contractors need the RIGHT answer; are you sure it's the one you get from Slashdot?
I hate appeals to authority, but this is getting old.
I have a degree in Mechanical Engineering, including a course in HVAC design and a number of them in thermodynamics.
Most of my career has been in building construction for General Contractors and Building Owners, dealing specifically with HVAC system installation and troubleshooting in everything from commercial, industrial, laboratory, and data centers.
You are purposely misreading my statements and attributing meanings that do not fit reality, much less what I was saying.
In my first post, I was talking about free cooling, which is bringing air directly in to a space because it is already cooled. I also responded to your comment "dehumidification only shouldn't necessarily require running a coil with the 20-30 degree temperature gap that the AC coil requires, thus saving some energy.", because it is untrue, and I gave reasons.
You turned it into heat exchangers, and your rebuttal to my comments on dehumidification violate physical laws, and I pointed that out.
Now, it's ALL about dehumidification "This is a brutally stupid statement. Dehumidifiers run the outside air over the cool coils to dehumidify it, then over the hot coils to re-heat it."
No shit - that's what I said before regarding residential units.
"THAT is the heat exchange."
Not really - it's a refrigeration cycle. It uses heat exchangers (refrigerant to air) as components, but the net is heat INPUT into the space.
"You'd be an idiot to run it over the hot coils first, that's the exact opposite of what you need."
And since I was addressing your comments regarding residential outside air heat exchangers, I poined out how stupid that would be. Somehow, when I was talking about outside air heat exchangers, you thought I was talking about dehumidifiers.
"Why you're confusing the simple operation of a dehumidifier with residential heat exchangers, I haven't a clue."
I don't think I'm the one who is confused here. Do you have any qualifications at all to be saying the things you are saying?
I didn't even address these beauties:
"No, what you do is install a second fan."
Regarding the second fan, what do you get? More airflow? If the duct size is the same, your pressure goes way up, and your velocity. So you are burning the same amount of energy - actually more, because large fans are typically more efficient than small, what with motor losses, etc.
"It's a patently ridiculous claim, anyhow. If you couldn't blow-in enough cool air from outside, then you couldn't move enough air to/from the AC units.."
Sure about that? In a server room the is typically very little ductwork - a raised floor acts as a plenum, and short return duct go back to the air handler which is in or right next to the room. If you are bringing air in from the outside, unless the room is near an outside wall there is ductwork required to carry the air, sometimes long runs. The ductwork resists air flow and conducts heat into the airstream, so larger fans and cooler air are required. And you want to run this ductwork for that portion of the year when free cooling is feasible? Especially when those same climactic conditions make conventional cooling system much more efficient? What's the ROI on that?
If you are going to troll, at least know SOMETHING about your topic.
Are you stupid? A heat exchanger (btw, not "very common" at all in residential) is the OPPOSITE of free cooling! In free cooling, COLD outside air is brought directly into the space, bypassing the cooling coils. Why? Because the air is cool already.
With a heat exchanger, you are bringing cool air in, and then HEATING IT UP with the waste heat from the exhaust air. Great for saving energy in a residence, when one wants to stay toasty warm - not so great in a data center or office building when there is still a cooling load in winter. So absolutely nothing you said has anything to do with free cooling. Heat exchangers are great for what they do, but free cooling isn't it.
"That's also untrue. The direct, free-flowing heat exchange between hot and cold coils allows dehumidifiers to be much more energy efficient, using typically around 1/3rd as much power for the same volume of air."
True - IF you are using a heat exchanger. But if one is not - lets say, in an office building on a cool spring morning - then you have a problem. You bring in nice 65F air, at 65-70% RH - it's wet. You don't heat it up through a HX, because you need the 65F air to maintain temp setpoint. But now you are dumping a lot of water into the space, and it doesn't *feel* cool. So, you run your cooling coil at, say 50F discharge temp. That is below dewpoint, and it pulls moisture out of the air. But now you are dumping 50F air into the space, so the space temp gets driven down, and you get the nipple effect. So what do you do? REHEAT the air to 65F. Which, BTW, is exactly what home humidifiers do - the discharge air is reheated to a temp greater than the intake air, reflecting the energy added by the electricity. TANSTAAFL.
You can throw a HX in that equation, but it certainly isn't a dumb device - the control logic needs to know when to open the air dampers and close them, so as not to interfere with free cooling.
"As to coil temperature, obviously any temperature will work, to varying degrees of effectiveness. You'll need to provide some numbers to back up your claim. General-purpose dehumidifiers are usually just slightly modified AC units"
Bullshit. The coil temperature MUST be less than the dew point of the air, by the very definition of "dew point". Practically, it needs to be substantially less for the dehumidification to really work. Often, that temp is less than desired for discharge air temp. See above example.
Call me when you've bought a psychrometric chart and a ductulator. There are plenty of design decisions to be made when designing an HVAC system, unfortunately including appeasing owners who think they are design geniuses.
What you and the OP are describing is called "free cooling", a long established principle in HVAC design. It is used in commercial and industrial buildings all the time. The reason that it is not used in residential all that much is that
1) until relatively recently, houses "breathed" quite well on their own due to loose construction. With tightening energy codes and the use of Tyvek and better windows, houses don't have a lot of air exchange through the boundaries, and problems ensue - "stuffiness", moisture, mold, "sick building". Residential construction hasn't thought this through yet - there are some builders who now refuse to use Tyvek due to ventilation (and liability) issues.
2) Controls become an order of magnitude more complicated. Most residential systems are "bang bang" systems - it's on or off based on 1 criteria. To introduce free cooling, you need outside air sensors, dampers, actuators, and a controller a lot more complex than a home t-stat. For most ersidential builders, that's a couple thousand in extra costs that can't be recouped in sale price - most owners just don't care, and when you are building 5000 of the same unit, "most owners" rule.
As for dehumidification, you have it backwards - dehumidification typically required a COLDER coil than necessary for cooling alone, and then you reheat the air. It is horribly inefficient, but sometimes necessary - with a "tight" building, you have to get the moisture out somehow, and supercooling the air inside just isn't a good idea (other than making for lots of erect nipples, that is)
Finally, what makes sense for one situation may not for another - a data center uses orders of magnitude more cooling than a house or common office building. Moving the amount of air necessary to provide that cooling gets really hard - the amount of energy a fan requires increase with the CUBE of the flow required. So to get twice the airflow you use 8x the power. It's the same with pumps, but because the heat capacity of water or glycol is so much greater than that of air, the effects are minimized.
Not exactly - it has more to do with starting the compresor against full high-side pressure. The critical time preiod is "finish to start", not "start to start".
Short and sweet link.
https://hsb.com/thelocomotive/RecentClaims/FullStory/RC-FS-LOCOCL9.html
Perhaps you should consult with your homophone: www.liebert.com
Really, I thought your link was a spoof site until I read your user name.
The general rule that I follow in such a situation is HIRE A PROFESSIONAL! There are people who do this stuff all the time, and actually have insurance in case they screw up their calcs - they're called HVAC engineers. Use one.
And please let me know the name of your company so I can sell it's stock short - what the fuck are they doing having someone "specifying" a server room who can't figure the loads?
Part of the problem is that it is a lot easier to move heat via liquid than air. the conventional design uses chillers mounted outside the space to cool a liquid medium/refrigerant, which is then pumped very efficiently to cooling coils in the space (modify for DX coils). the air inside the condityioned space makes a very short trip through the servers, across the room, over the coil, and back out again.
Under your scenario, the AIR is the working medium - it is cooled on the outside, and then moved inside via relatively inefficient fans. And it is a SHITLOAD of air - that means either high volumes (huge ductwork) or high velocity (how do you like working in a wind tunnel?).
Fans on UPS? Are you kidding? How big do you want your UPS to be? Fans suck a LOT of power, especially when you have them doing what you propose.
"as part of the design for the cluster room in our new building I've specified such a system"
You've specified? From your post, it's obvious you aren't an HVAC engineer, so what are your qualifications? Did you do an analysis to see what the real ROI is? Or is it just so obvious to you why years of HVAC design are totally wrong?