“Cold Tube” cooling system uses half the energy of an air conditioner
1–10 of 137 posts
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#2This sounds pretty neat, but their description of cold things sucking thermal radiation doesn't jive with my freshman-physics understanding of thermodynamics. AFAICT they've got cold water circulating in a moisture-repellent membrane, so they're able to absorb heat by chilling the water in the pipes instead of fussing with the humidity in the air like most AC does. So it sounds like trading inefficiency of standard AC units for an inefficient thermal interface -- you need to stand next to it to feel cooled?
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#3This sounds pretty neat, but their description of cold things sucking thermal radiation doesn't jive with my freshman-physics understanding of thermodynamics. AFAICT they've got cold water circulating in a moisture-repellent membrane, so they're able to absorb heat by chilling the water in the pipes instead of fussing with the humidity in the air like most AC does. So it sounds like trading inefficiency of standard A…
It might be better to think of it as creating an environment where you are not surrounded by warm objects radiating at you. So it should not matter where you are in the space or how large it is. The effect should be the same.
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#4Pretty cool
(sorry)
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#5This sounds pretty neat, but their description of cold things sucking thermal radiation doesn't jive with my freshman-physics understanding of thermodynamics. AFAICT they've got cold water circulating in a moisture-repellent membrane, so they're able to absorb heat by chilling the water in the pipes instead of fussing with the humidity in the air like most AC does. So it sounds like trading inefficiency of standard A…
About 60% of human body heat is lost through radiation. The cooling you would feel would be proportional to the percentage of the area around you that is covered by these cooling walls. Distance wouldn't cause that much loss because the air doesn't absorb much radiation in blackbody range of humans over distances less than 50 meters.(Infrared range with intensity peaking at 93 thousand angstroms)
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#6This sounds pretty neat, but their description of cold things sucking thermal radiation doesn't jive with my freshman-physics understanding of thermodynamics. AFAICT they've got cold water circulating in a moisture-repellent membrane, so they're able to absorb heat by chilling the water in the pipes instead of fussing with the humidity in the air like most AC does. So it sounds like trading inefficiency of standard A…
It's the cooling equivalent of a radiant heater, and you need line-of-sight to the walls to feel cooled. The thermal interface is deliberately inefficient for convection (to avoid wasting power chilling the air), but efficient for radiation.
Radiation is proportional to absolute temperature T^4. So compared to a glowing radiant patio heater, I'd expect to need maybe (1000^4 - 300^4)/(300^4 - 270^4) ~ 350x the area for the same heat transfer in the opposite direction, thus their big tunnel instead of a little filament. Even with their cold source at absolute zero, they'd still need >100x.
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#7> The notoriously bad energy efficiency of air conditioners
Air conditioners are actually pretty fantastically efficient for what they do. The problem with air conditioners is that there's no way to move a ton of heat without using a lot of energy. So, they do use a lot, but they make the most of it.
What's truly bad are our buildings that have the minimal insulation and sealing possible, leaking all that cold air right back out into the environment.
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#8This sounds pretty neat, but their description of cold things sucking thermal radiation doesn't jive with my freshman-physics understanding of thermodynamics. AFAICT they've got cold water circulating in a moisture-repellent membrane, so they're able to absorb heat by chilling the water in the pipes instead of fussing with the humidity in the air like most AC does. So it sounds like trading inefficiency of standard A…
It's the cooling equivalent of a radiant heater, and you need line-of-sight to the walls to feel cooled. The thermal interface is deliberately inefficient for convection (to avoid wasting power chilling the air), but efficient for radiation. Radiation is proportional to absolute temperature T^4. So compared to a glowing radiant patio heater, I'd expect to need maybe (1000^4 - 300^4)/(300^4 - 270^4) ~ 350x the area fo…
And you still have to pump the heat out to somewhere else.
The whole premise with this system is that you can keep the temperature higher so you have to pump less heat, which I'm extremely skeptical of, at least for indoor environments.
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#9I wonder how costly it is to fill your walls entirely with water pipes.
Also, one currently ensures there is a stud or lack of electrical when putting nails in a wall. I guess you gotta hang things up differently.
Re: “Cold Tube” cooling system uses half the energy of an air conditioner
#10> The notoriously bad energy efficiency of air conditioners Air conditioners are actually pretty fantastically efficient for what they do. The problem with air conditioners is that there's no way to move a ton of heat without using a lot of energy. So, they do use a lot, but they make the most of it. What's truly bad are our buildings that have the minimal insulation and sealing possible, leaking all that cold air ri…
There’s also no obvious market factor incentivizing modernization of old RE let alone efficiency.