7 ms·

Wouldn't it be more efficient to just use water run through a coil 6 ft underground? In most areas that have the intense heat that running water over the radiat

Wouldn't it be more efficient to just use water run through a coil 6 ft underground? In most areas that have the intense heat that running water over the radiators actually would help, the ground 6 ft below is pretty easily cooler than 5-10 degrees C. The electricity to pump 6 ft down couldn't be that much more either... And when it isn't as hot out, you can actually use the ground temp to radiate heat out of the house by itself, no need for coils and a fan to run in ambient air temp, right?

fragsworth 9y ago
Maybe digging is impractical in a lot of situations?
renlo 9y ago
The problem is that with ACs/power plants, the net temperature will rise if you do this because it's a closed system. Power plants and ACs are not 100% efficient; the power plant converts chemical/nuclear/mechanical energy into electrical energy, releasing heat from work lost. Your AC will convert electrical energy to cool the air around you, but because it is not 100% efficient, the total temperature of the system will rise. There needs to be a way to get rid of that lost energy and remove it from the system. If you put that into the ground, it's still in the system. Ofc, even when they try to 'beam the heat to space', much of it will end up staying in the system (earth) as it reflects on clouds / water vapor, etc.
- Swizec 9y ago
  Isn’t this basically what happened with the London underground? It used to be cold down there now it’s super hot as the soil can’t absorb more heat. Source: https://www.forbes.com/forbes/welcome/?toURL=https://www.forbes.com/sites/lauriewinkless/2017/06/22/sweating-on-the-underground-why-are-tube-tunnels-so-hot/&refURL=https://www.google.com/&referrer=https://www.google.com/ https://www.forbes.com/forbes/welcome/?toURL=https://www.for... > According to this article in Rail Magazine, the average temperature inside the tunnels was around 14° in 1900. > increased the temperature of the surrounding clay so much that, today, average tunnel temperatures are between 20-25°C.
  - kbenson 9y ago
    That sounds like a good way to bank energy for later use during London winters, if you ask me.
- Florin_Andrei 9y ago
  I forget the exact number, but the clear night sky is equivalent to a very cold black body radiator, around -30C or so (can't recall the actual value and it probably depends on local temperature too). Radiative equilibrium with it will push your temperature way down. This is the main reason why it suddenly gets so cold at night. From a radiative perspective, you might as well be facing a ceiling of Arctic ice above you. I'm an amateur astronomer. When I do observations at night, I always add an extra layer of clothing. It's amazing just how really cold it gets when all you do is sit under the clear night sky. When it's cloudy it's different. The chill effect due to the (lack of) radiation is much less intense.
andrewtbham 9y ago
Bosch makes geothermal heating and cooling units. http://geothermal.boschprohvac.com/site/geothermal-explained.html http://geothermal.boschprohvac.com/site/geothermal-explained...
- dennisgorelik 9y ago
  These geothermal solutions are quite pricy: https://www.google.com/search?q=geothermal+price https://www.google.com/search?q=geothermal+price --- a typical home of 2500 square feet, with a heating load of 60,000 BTU and a cooling load of 60,000 BTU will cost between $20,000 to $25,000 to install. ---
  - bhickey 9y ago
    The estimate I got for a well alone was about $40,000.
    - andrewtbham 9y ago
      Obviously, it's a renewable energy source. But this is also a premium German product. It's designed to be quiet. So you don't have a loud AC roaring in your yard all summer. That allows builders to build houses closer together in premium developments such as serenbe GA.
hwillis 9y ago
Better solution: stop creating heat in the home. Instead of using gas or electricity to heat water, use a heat pump joined to the A/C. Store greywater and heat that up, then send it down the sewers. A liter of water has the same heat capacity as 3 cubic meters of air and a person uses 300+ liters of water per day, enough to cool 3200 square feet of house by 10 F.
- todd8 9y ago
  For a while in the 70's, inspired by a book I'd read (maybe Nomadic Furniture, by Papanek and Hennessey) I took my showers with the drain closed. I would paddle around in the ankle deep warm water and leave it in the tub until cool, thus warming my chilly bathroom and small apartment for "free".
- vinceguidry 9y ago
  People each put 300+ liters of greywater through the sewer system? Seems a tad bit high.
  - XR0CSWV3h3kZWg 9y ago
    US puts water consumption per capita at 2,842 cubic meters per annum. (2,842 cubic meters in liters)/365 = 7.7k liters.
    - Johnny555 9y ago
      That's all water use, not household or office use that could be used for this purpose. For example: Meat consumption accounts for 30 percent of the American figure, and sugar consumption is responsible for another 15 percent https://www.scientificamerican.com/article/graphic-science-how-much-water-nations-consume/ https://www.scientificamerican.com/article/graphic-science-h...
    - jdmichal 9y ago
      I'm guessing that number is for all uses. Obviously, as being discussed, industrial and agricultural water uses would not be eligible. The USGS [0] estimates 23,800 mega-gallons per day for domestic use by 268 million people. This is about 89 gallons or 336 liters per day per person. [0] https://water.usgs.gov/watuse/wudo.html https://water.usgs.gov/watuse/wudo.html
randyrand 9y ago
No. The ground around the pipes will heat up very quickly.
bullfightonmars 9y ago
This is a common and easily available technology for residential and commercial applications. With a closed-loop system a 4-ton HVAC system requires roughly 600ft of 3/4-inch pipe as vertical wells. That typically means 4 wells maybe 15-20 feet apart. You need a decent about of property to support these systems, enough room for a well driller, appropriate drilling conditions, permits for drilling, etc. There are other systems for people with the land which may be less expensive which don't require drilling. I spent several summers installing these systems, they are surprisingly simple and effective. https://en.wikipedia.org/wiki/Geothermal_heat_pump https://en.wikipedia.org/wiki/Geothermal_heat_pump
Johnny555 9y ago
It takes the right kind of soil/moisture for good thermal contact, and it can take a very large (length and/or depth) group loop for something like an office building. There are limits to the technology. Skyscrapers are simply too large for any reasonable number of wells to provide adequate heating and cooling, Mr. Orio said. And it would be very difficult to install a well beneath an existing structure. http://www.nytimes.com/1997/04/20/nyregion/new-building-will-use-a-geothermal-energy-system.html?mcubz=0 http://www.nytimes.com/1997/04/20/nyregion/new-building-will...
lathiat 9y ago
This seems like a good time to raise that pumping heat into the surrounding soil doesn't work forever. For a home aircon it might be OK, however the London Tube is having serious problems with this where many of the tube tunnels have warmed from around 14C to nearly 30C (57-86F) over the last 100 years. Leaving many of them quite hot. The surrounding ground around the tubes has warmed up and effectively heat soaked. Heat is generated from a number of sources including diesel engines however apparently a large portion of the heat is generated by braking for each station. They've improved that by using electric regenerative braking now which in some cases can dump the power into other trains that are accelerating at the same time. Some of the newer trains now also have air conditioning inside the trains, while that helps inside the train it doesn't help outside the train where even more heat is dumped. Anyway for more information there is a good youtube video I can't find right now, so you could read this instead: https://www.forbes.com/sites/lauriewinkless/2017/06/22/sweating-on-the-underground-why-are-tube-tunnels-so-hot/#3aaca8cd5234 https://www.forbes.com/sites/lauriewinkless/2017/06/22/sweat... https://www.ianvisits.co.uk/blog/2017/06/10/cooling-the-tube-engineering-heat-out-of-the-underground/ https://www.ianvisits.co.uk/blog/2017/06/10/cooling-the-tube... https://en.wikipedia.org/wiki/London_Underground_cooling https://en.wikipedia.org/wiki/London_Underground_cooling

fragsworth 9y ago

Maybe digging is impractical in a lot of situations?

renlo 9y ago

The problem is that with ACs/power plants, the net temperature will rise if you do this because it's a closed system. Power plants and ACs are not 100% efficient; the power plant converts chemical/nuclear/mechanical energy into electrical energy, releasing heat from work lost. Your AC will convert electrical energy to cool the air around you, but because it is not 100% efficient, the total temperature of the system will rise. There needs to be a way to get rid of that lost energy and remove it from the system. If you put that into the ground, it's still in the system. Ofc, even when they try to 'beam the heat to space', much of it will end up staying in the system (earth) as it reflects on clouds / water vapor, etc.

Swizec 9y ago
Isn’t this basically what happened with the London underground? It used to be cold down there now it’s super hot as the soil can’t absorb more heat. Source: https://www.forbes.com/forbes/welcome/?toURL=https://www.forbes.com/sites/lauriewinkless/2017/06/22/sweating-on-the-underground-why-are-tube-tunnels-so-hot/&refURL=https://www.google.com/&referrer=https://www.google.com/ https://www.forbes.com/forbes/welcome/?toURL=https://www.for... > According to this article in Rail Magazine, the average temperature inside the tunnels was around 14° in 1900. > increased the temperature of the surrounding clay so much that, today, average tunnel temperatures are between 20-25°C.
- kbenson 9y ago
  That sounds like a good way to bank energy for later use during London winters, if you ask me.
Florin_Andrei 9y ago
I forget the exact number, but the clear night sky is equivalent to a very cold black body radiator, around -30C or so (can't recall the actual value and it probably depends on local temperature too). Radiative equilibrium with it will push your temperature way down. This is the main reason why it suddenly gets so cold at night. From a radiative perspective, you might as well be facing a ceiling of Arctic ice above you. I'm an amateur astronomer. When I do observations at night, I always add an extra layer of clothing. It's amazing just how really cold it gets when all you do is sit under the clear night sky. When it's cloudy it's different. The chill effect due to the (lack of) radiation is much less intense.

andrewtbham 9y ago

Bosch makes geothermal heating and cooling units. http://geothermal.boschprohvac.com/site/geothermal-explained.html http://geothermal.boschprohvac.com/site/geothermal-explained...

dennisgorelik 9y ago
These geothermal solutions are quite pricy: https://www.google.com/search?q=geothermal+price https://www.google.com/search?q=geothermal+price --- a typical home of 2500 square feet, with a heating load of 60,000 BTU and a cooling load of 60,000 BTU will cost between $20,000 to $25,000 to install. ---
- bhickey 9y ago
  The estimate I got for a well alone was about $40,000.
  - andrewtbham 9y ago
    Obviously, it's a renewable energy source. But this is also a premium German product. It's designed to be quiet. So you don't have a loud AC roaring in your yard all summer. That allows builders to build houses closer together in premium developments such as serenbe GA.

hwillis 9y ago

Better solution: stop creating heat in the home. Instead of using gas or electricity to heat water, use a heat pump joined to the A/C. Store greywater and heat that up, then send it down the sewers. A liter of water has the same heat capacity as 3 cubic meters of air and a person uses 300+ liters of water per day, enough to cool 3200 square feet of house by 10 F.

todd8 9y ago
For a while in the 70's, inspired by a book I'd read (maybe Nomadic Furniture, by Papanek and Hennessey) I took my showers with the drain closed. I would paddle around in the ankle deep warm water and leave it in the tub until cool, thus warming my chilly bathroom and small apartment for "free".
vinceguidry 9y ago
People each put 300+ liters of greywater through the sewer system? Seems a tad bit high.
- XR0CSWV3h3kZWg 9y ago
  US puts water consumption per capita at 2,842 cubic meters per annum. (2,842 cubic meters in liters)/365 = 7.7k liters.
  - Johnny555 9y ago
    That's all water use, not household or office use that could be used for this purpose. For example: Meat consumption accounts for 30 percent of the American figure, and sugar consumption is responsible for another 15 percent https://www.scientificamerican.com/article/graphic-science-how-much-water-nations-consume/ https://www.scientificamerican.com/article/graphic-science-h...
  - jdmichal 9y ago
    I'm guessing that number is for all uses. Obviously, as being discussed, industrial and agricultural water uses would not be eligible. The USGS [0] estimates 23,800 mega-gallons per day for domestic use by 268 million people. This is about 89 gallons or 336 liters per day per person. [0] https://water.usgs.gov/watuse/wudo.html https://water.usgs.gov/watuse/wudo.html

randyrand 9y ago

No. The ground around the pipes will heat up very quickly.

bullfightonmars 9y ago

This is a common and easily available technology for residential and commercial applications. With a closed-loop system a 4-ton HVAC system requires roughly 600ft of 3/4-inch pipe as vertical wells. That typically means 4 wells maybe 15-20 feet apart. You need a decent about of property to support these systems, enough room for a well driller, appropriate drilling conditions, permits for drilling, etc. There are other systems for people with the land which may be less expensive which don't require drilling. I spent several summers installing these systems, they are surprisingly simple and effective. https://en.wikipedia.org/wiki/Geothermal_heat_pump https://en.wikipedia.org/wiki/Geothermal_heat_pump

Johnny555 9y ago

It takes the right kind of soil/moisture for good thermal contact, and it can take a very large (length and/or depth) group loop for something like an office building. There are limits to the technology. Skyscrapers are simply too large for any reasonable number of wells to provide adequate heating and cooling, Mr. Orio said. And it would be very difficult to install a well beneath an existing structure. http://www.nytimes.com/1997/04/20/nyregion/new-building-will-use-a-geothermal-energy-system.html?mcubz=0 http://www.nytimes.com/1997/04/20/nyregion/new-building-will...

lathiat 9y ago

This seems like a good time to raise that pumping heat into the surrounding soil doesn't work forever. For a home aircon it might be OK, however the London Tube is having serious problems with this where many of the tube tunnels have warmed from around 14C to nearly 30C (57-86F) over the last 100 years. Leaving many of them quite hot. The surrounding ground around the tubes has warmed up and effectively heat soaked. Heat is generated from a number of sources including diesel engines however apparently a large portion of the heat is generated by braking for each station. They've improved that by using electric regenerative braking now which in some cases can dump the power into other trains that are accelerating at the same time. Some of the newer trains now also have air conditioning inside the trains, while that helps inside the train it doesn't help outside the train where even more heat is dumped. Anyway for more information there is a good youtube video I can't find right now, so you could read this instead: https://www.forbes.com/sites/lauriewinkless/2017/06/22/sweating-on-the-underground-why-are-tube-tunnels-so-hot/#3aaca8cd5234 https://www.forbes.com/sites/lauriewinkless/2017/06/22/sweat... https://www.ianvisits.co.uk/blog/2017/06/10/cooling-the-tube-engineering-heat-out-of-the-underground/ https://www.ianvisits.co.uk/blog/2017/06/10/cooling-the-tube... https://en.wikipedia.org/wiki/London_Underground_cooling https://en.wikipedia.org/wiki/London_Underground_cooling