The "air conditioners in uninsulated tents" thing was always kind of jarring to me.
Part of it is due to accounting -- operational expenses like fuel are treated as operations expenses, but building buildings is a capital improvement and has a different budgeting process.
The tents I've seen with A/C units (this was early 90s) were made of a different fabric than the standard tents we berthed in. I believe this was a sort of insulated tent to retain the cooled air. Another reason for the A/C units was to filter dusty air to keep that grit away from computers.
By comparison, the NASA budget is $20 Billion.
The cost to give every child in America a free school lunch is $20 Billion.
The National Science Foundation (NSF) is requesting less than $8 Billion this year.
The entire National Institute of Health (NIH) budget is $31 Billion.
The Environment Protection Agency responsible for assuring breathable air & safe water against every corporate interest is asking for less than $9 Billion this year.
The U.S. “Smart Grid” industry is worth $21 Billion.
Things like this really just blow my mind. Our world is getting more and more complex each year, and out voters are not being more and more sophisticated. And our electioneering systems are not doing anything to aid that either.
I am an optimist but if our nation sees significant decline ahead, I think it's in no small part due to the drag of our BS political cluster^^^^ in Washington DC.
As a great American once said, "Our problems are man-made, therefore they may be solved by man." The trouble to me is that we've got nobody minding the store. People support policies -- on both sides of the aisle -- that are obviously and objectively against their self interest because they buy into political advertising and dogma the same way they buy into I'm a Mac, I'm a PC.
I'm an optimist, but i see precious few problems being solved by those we the people hire to do our statecraft.
You'd be lucky to have that 25 watt solar panel power a fan much less an AC unit. Most in-window a/c units take about 600 - 1200 watts. They also run on A/C power, not DC which is what you get from solar panels. Getting enough amperage from a solar panel is going to be difficult.
Unless of course you were to put some isolation in those tents (or regular buildings, for the matter).
The ingenious building style in hot countries revolves around few windows, light colors and thick walls. With that, there is not much need for air conditioning.
But then again, the US has a track record of building inefficient houses, so this should not surprise anyone.
Making mud huts doesn't seem very realistic in the middle of a sandy desert, a war zone or a disaster area. Nor are they entirely easy or quick to build & their ability to cool would be temperamental & inconsistent.
There aren't any bases literally in the middle of a sandy desert, as what are you defending in that case? They're usually somewhere on more solid ground. If there's dirt, there's material for building. There are no bases of any consequence in the middle of the Sahara. Iraq isn't Saudi Arabia.
Rammed Earth construction (http://en.wikipedia.org/wiki/Rammed_earth) is an ancient practice made easy with modern equipment. The tents the American forces use are better suited to a European climate, not the intense heat of the desert. They're also going to resist mortars a lot better than some flimsy canvas tent.
The military could invest in compact, easily constructed tents or it could rely on the possibility that mud is available in the area & that they have the time, the personnel & the heavy equipment free to build them. Huts that you can't deconstruct and take with you.
Also we're not just talking about military purposes. You could put up an industrial grade tent in an hour for disaster relief. How long would a mud hut take to build in a disaster area? How about at a festival or fairgrounds?
It looks like in some areas the army is re-purposing tents for semi-permanent housing. Tents are already on hand. Their specs are known. I am not aware of an army approved mud hut. Perhaps the army should look into it, but there are many varying factors that can go wrong in constructing a mud hut vs a standard issue tent.
Also I don't think a quickly build mud hut is going to fair a whole lot better than a tent to a mortar round. Additionally the tents are being sprayed with insulating foam on the outside which makes them almost airtight. Though I'd question if there is the ability to re-purpose the tent after it's been sprayed.
How difficult would it be to do a geo-thermal like system? Instead of coolant + heat exchanger, can you just force warm air down some pipes buried in the earth (running some distance) and having the thermal exchange occur "naturally" to surface as cool air at the other end of the pipe? In which case, (solar) fans might be all that is needed to run the system (though burying the pipes would require some work)
You are talking about a Ground source heat pump. Once you are down about 10m the temperature of the ground is fairly constant at about 10-14 degrees C. You can exploit this temperature difference for either heating or cooling using a heat pump.
Indeed though the ones I've read about uses some type of liquid coolant for heat/cool interchange. Just curious if circulating just air through the piping would suffice as a poor-mans implementation thus reducing the need for the above ground exchanger.
I think the biggest reason against solar powered <anything> is that 'solar' doesn't mean 'free'.
Last time I've checked solar panels were just a way to transport energy (kind of like a battery). I.e. you have to invest $X into panel manufacturing to receive $Y worth of electricity in some remote location with no power. Several years ago $X was equal $Y.
Granted, technology is improving and panels cost less and less, now $X << $Y. But even today solar based solutions are not economical without goverment incentives.
...made out of a special mortar called sārooj, composed of sand, clay, egg whites, lime, goat hair, and ash in specific proportions, and which was resistant to heat transfer. This mixture was thought to be completely water impenetrable.
Yes. As a taxpayer in one of the higher tax brackets (like most here are i presume) I sincerely hope they plan infrastructure on established bases the way you describe.
The US Military has a habit of staying where it goes. Many people have opinions on that, I do not, but I am a realist so I think its fair to assume that if you've got a large, established base in a warzone (like the Green Zone in Baghdad), treat it like you'll be using it for 100 years. Because if history is any indication, you will be.
That doesn't work well, at least in this case. From the article, "We're turning over to the Iraqis — mostly either for a small penny or for free — the infrastructure that we built in Iraq. But we won't see back any money from that infrastructure."
At first, I was going to say it's tiny relative to the overall DoD budget... but if true, it's actually pretty ridiculous:
- 0.5% of the US federal budget overall (including entitlement programs)
- 3-4% of the overall defense budget
- More than 2x the budget of the FBI
- ~40% of the Homeland Security budget ($47B)
- Rather close to the budget allocation for the Marine Corp ($29B) (though there might technically be some overlap there)
If that's for 2 wars in 2 countries, what's government's total air conditioning bill? Our soldiers deserve it, but there's gotta be a better way.
I'd consider an evaporation cooler/swamp cooler to be a "solar powered A/C system" -- these are widespread and cheap. Add a solar powered fan for circulation and it could be 100% solar.
The point was: Get over the inertia and do something about the idea (finding and importing solar powered a/c's). "Pretty dick"? I guess it might be perceived like that. Wasn't intended though, hence the :-)
Can air conditioners be driven directly by gasoline engines rather than generators->electrical AC? Perhaps just replacing the electro-compressor with an in-place gas version.
Yes, but it's not really a good idea in this kind of environment.
Generally they'd run 200-500KW diesel generators in a unit generator farm, then run power cabling (3 phase) out to PDUs in clusters of tents, with single-phase runs to standard military ECUs (air conditioners) attached to each tent. They also need electricity INSIDE the tents, for computers, lighting, etc.
Generators are noisy, need to be serviced and fueled, and the small ones (~10KW) that you'd want to run on an HVAC are less efficient (especially for diesel), loud, etc. You also don't want fuel tankage near tents which might be hit by incoming mortars...especially mogas (gasoline) tankage...JP8/Jet-A/diesel is a fair bit less bad.
Over time, they moved to a "prime power" system for the larger bases, with a big farm of 2MW gensets run by a contractor, and an on-base power distribution system, sort of like towns in Alaska, islands, etc.
Using an engine to directly run HVAC is done on reefers (insulated/refrigerated shipping containers), but even those are moving more and more to electrical hookups (so when they're in a big storage area, they can all be connected to cheaper power).
Some of this power was for things like a 20 x 20 grid of 16-man tents, each with HVAC.
I still think the primary consumer of liquid fuels was aviation -- fighters taking off on afterburner, big cargo aircraft transporting tens of tons per load, helicopters, etc.
If we figure - generously - that an American consumes $100/mo of A/C at work + another $100 at home for six months, that is $1,200 for the year per capita
For the 150,000 soldiers in Iran and Afghanistan, the $20B comes to $130,000 per capita, or over 100x more
Just a fun comparison, not saying one way or the other here.
UK new build "best practice building" say about 140 kWh per square meter per year total energy use (including HVAC). 8 square meters per person is packed in desks like a call centre. £0.1 per kWh. 140 * 8 * 0.1 ~ £100 per year per person = $160. Cheaper power costs in US. More extreme temperature differences. Less strict energy conservation codes. All could skew this figure considerably.
Yeah, the AC is about 40kWh/year. Its not doing much for about 3/4 of the year in the UK though. Economies of scale do make a big difference. In a large building with 1000's of peeps air supply fans (fan coil units), chillers and heat rejection would be separate pieces of kit. Heat rejection is generally done by rooftop cooling towers sometimes supplemented by ground sink borehole. Supply air is cooled at the fan coil units, which are supplied by with water cooled by the chillers. There are lots of variations for a system like this but as described above is a pretty typical office building set-up in the UK building industry at the moment.
I wasn't doubting your numbers, I haven't confirmed but you seem to know what you're talking about.
I just had an intuitive problem with the original post's assertion that office-space cooling in permanent structures could be anywhere near as expensive to run as cooling non-permanent structures in a 120 degree desert warzone, serviced by Halliburton contractors.
This is why much more transparency is necessary. So we can question expenses such as these. Who knows how many hundreds of billions more are wasted for similar things?
I am honestly wondering what the average temperature in a Bedouin or Mongolian (sorry, for lack of better term) tent is and how one could apply this to troop tents in the desert in general and ultimately save on A/C and fuel because many generations of men have proven to successfully survive in the desert long before fuel and a/c has been invented.
My brother was stationed in Kuwait several years ago (waypoint to be deployed to Iraq). During the summer they had days where the temperature was around 140F (60C). The mean in August is 131F (55C) - http://en.wikipedia.org/wiki/Kuwait#Geography_and_climate
Think about how hot that is for a moment. Now imagine having to do heavy physical activity in it, moving large equipment, carrying 80 pounds of gear, hiking everywhere, etc... Your odds of developing heat stroke are extremely high.
Having a cool place to relax and recover in is absolutely necessary. Otherwise, plenty of soldiers would be suffering and/or dying. The overall shape of the military stationed there would decline, and would lose that advantage over their enemy.
People living in the desert dress in a particular way and adapt to the heat.
They also build their permanent structures in a way that maximizes airflow and cools the building. There was a NYT article a few years ago about an 800 year old, un-air conditioned mosque in Baghdad where the temperature was in the low 70's year round.
Pre air-conditioning, western buildings had features like this as well.
Post air-conditioning, European buildings are still built like that. Most housing buildings in Europe do not have air conditioning, even in the subtropical south.
Speaking of the south, many many buildings in Greece and Italy have a simple mirror and a steel tank on their roofs to supply hot water. No electricity or sophistication needed.
Even in the cold north, simple radiators provide enough heat to keep a house warm. Thick walls and small windows are enough to contain air temperatures in both cold Finland and hot Greece.
I'm slightly frustrated by my current apartment in this regard -- it's an older building, built with the assumption of no air conditioning. There are vents on the interior walls to allow air flow with the interior hallway, which is always pleasantly cool. The management has shuttered those vents, but not added any AC!
I have seen an airflow system in a newly built house to keep all rooms supplied with fresh air even without opening windows or doors and I think it is a fantastic concept - at least when considering the house was built outside the city.
I think this is called "heat recovery ventilation" in English.
many generations of men have proven to successfully survive in the desert long
I cannot speak for current operations - in the 90s we did not use A/C for the tents we lived in, but for the tents the computers were in. They also functioned as dust filters.
The "Mongolian" tent is called a yurt. And the Mongolian steppe's isn't even close to the same climate as Iraq. Might be a match for northern Afghanistan.
The Gobi is ridiculously varied (as is Mongolian really, it was wrong of me to generalize that much). That said, the Gobi is a relatively cold desert. High elevation plus relatively high latitude. My geography is kinda sketchy, so a quick google tells me that while the hottest part of the year can reach +30C (I guess approaching Iraq levels), temperatures in the north (the Mongolian part) are generally lower, and infact, you would probably be far more worried about how cold it gets than how hot (the famous Mongolian winters???).
Unfortunately, I can't really answer for the Bedouin.
hm I just looked at the wikipedia page quoting extreme temperatures up to 50°C but the challenge in the desert definitely is the huge fluctuation - considering it can go down as far as −40°C for Gobi.
Overall, this sounds like another point for thick, heavy tents (or in terms of the urban jungle: thick brick walls here in Europe keep wonderfully cool in summer and warm in winter.)
But I can also see how the a/c is probably one thing they do for keeping morale up... so this might not only be a thermic/physical problem.
Part of it is due to accounting -- operational expenses like fuel are treated as operations expenses, but building buildings is a capital improvement and has a different budgeting process.