Geothermal or similar cooling requires a pretty significant capital investment in order to work. My guess is that a basic air conditioning unit is a cheaper and simpler fix in most cases.
The problem is that even that fix may be out of the reach of many residents of Karachi.
By “people” I meant governments, companies or NGOs. Sure a basic AC unit is cheaper for one person, but it seems plausible that a piping system like the one I described would be a cheaper way to cool a large area. Note that AC will cool one person’s house, but contributes a net heating effect to the city.
It’s probably a lot more effective to draw the water from ~10m down; the infrastructure costs are far lower, you’ll probably not need to insulate the water quite so much for coastal regions (to keep it from warming en route to the surface), you won’t need to pump so hard (you won’t have a vertical kilometer of buoyancy for your denser-than-shallower-water to fight).
For coastal regions, this might actually work, though those tend to be relatively moderate to start with (courtesy of the water). It would be a ton of infrastructure to get in installed in more than a small, clustered set of buildings / public property, though. For inland regions, you then need to pump cold (it’s not permitted to warm up much) corrosive (seawater is a pain) water over a long distance in a hot part of the world. Upon its arrival, you still need to get it into the heat exchangers that you have installed wherever financially practical. Then you have to get rid of the resulting slightly-warmer corrosive seawater.
About a quarter of people in Pakistan regularly practice “open defecation” due to lack of access to basic plumbing infrastructure, which probably causes a much higher casualty rate than lack of access to air conditioning (old people are usually the casualties in heat waves, so the number of QALYs lost is much lower.) I know this isn’t directly an answer to your question, but I’m trying to illustrate that there is a huge infrastructure gap in there.
Also, I’m not sure how you envision this working; just having open trenches of cold evaporating saltwater throughout the city?
Sure, but people don’t try this in rich countries either. Places like Texas or Florida would be a lot nicer in the summer if they were 10 degrees cooler.
I’m not sure about the specifics, but there must be some way to get that cold out of the ocean depths and up to where people can benefit from it. People have been transporting large volumes of water since Roman times, and we have huge multibillion dollar oil rigs that drill through the ocean floor.
Eh.. There is indeed work being done on this. Google seawater greenhouse—Which is basically a way to engineer a cooler, wetter micro-climate and turn a net profit.
There was recently a lethal heat wave in Karachi.
If you go about 1000 meters below the surface of the ocean, the water gets very cold.
Why don’t people try to cool off hot places by piping cold water up from the ocean? Or just bubbling air through the deep water?
Geothermal or similar cooling requires a pretty significant capital investment in order to work. My guess is that a basic air conditioning unit is a cheaper and simpler fix in most cases.
The problem is that even that fix may be out of the reach of many residents of Karachi.
By “people” I meant governments, companies or NGOs. Sure a basic AC unit is cheaper for one person, but it seems plausible that a piping system like the one I described would be a cheaper way to cool a large area. Note that AC will cool one person’s house, but contributes a net heating effect to the city.
It’s probably a lot more effective to draw the water from ~10m down; the infrastructure costs are far lower, you’ll probably not need to insulate the water quite so much for coastal regions (to keep it from warming en route to the surface), you won’t need to pump so hard (you won’t have a vertical kilometer of buoyancy for your denser-than-shallower-water to fight).
For coastal regions, this might actually work, though those tend to be relatively moderate to start with (courtesy of the water). It would be a ton of infrastructure to get in installed in more than a small, clustered set of buildings / public property, though. For inland regions, you then need to pump cold (it’s not permitted to warm up much) corrosive (seawater is a pain) water over a long distance in a hot part of the world. Upon its arrival, you still need to get it into the heat exchangers that you have installed wherever financially practical. Then you have to get rid of the resulting slightly-warmer corrosive seawater.
About a quarter of people in Pakistan regularly practice “open defecation” due to lack of access to basic plumbing infrastructure, which probably causes a much higher casualty rate than lack of access to air conditioning (old people are usually the casualties in heat waves, so the number of QALYs lost is much lower.) I know this isn’t directly an answer to your question, but I’m trying to illustrate that there is a huge infrastructure gap in there.
Also, I’m not sure how you envision this working; just having open trenches of cold evaporating saltwater throughout the city?
Sure, but people don’t try this in rich countries either. Places like Texas or Florida would be a lot nicer in the summer if they were 10 degrees cooler.
I’m not sure about the specifics, but there must be some way to get that cold out of the ocean depths and up to where people can benefit from it. People have been transporting large volumes of water since Roman times, and we have huge multibillion dollar oil rigs that drill through the ocean floor.
Eh.. There is indeed work being done on this. Google seawater greenhouse—Which is basically a way to engineer a cooler, wetter micro-climate and turn a net profit.
There’s a way to transport water but that doesn’t mean it’s cost effective.