Geothermal with closed loop system

I came across an interesting video on Cheap Geo Thermal Air Conditioning.

The idea is you use antifreeze in buried 1inch water pipes, a pump, a car radiator and a fan.

It's an alternative to air filled pipes and a heat exchange.

No doubt it is significantly cheaper. But could it work? What are the draw backs? If it's so good, why can't I find any examples?  I guess I don't know the correct word for the tech and there's probably lots of information out there.

Have you used this tech?

Ground loop systems are well known. Usually they are paired with a heat pump that provides heating and cooling. The radiator and fan setup will work to cool a small room or tiny house. I am highly skeptical of its performance for greenhouse heating.

So yes, this can work. The question is capacity -- how many BTUs/kJ the system can move. That's where it gets complicated. Subsoil temperature, flow rate, fluid type, and the length of buried piping need to be matched to the need. It's a complex calculation.
If the system is too small, it won't perform worth a damn.

Memory is fuzzy, but I recall that heating my house with a ground loop and heat pump would have required something like a kilometer of buried piping. I can't swear to that; others here can hopefully chime in.

The other thing is redundancy. If I was disturbing that much ground, I would likely include spare pipe in case a failure occurred in the active pipe.

My 2c.

Thank you Douglas.

Small room or house sounds perfect. I'm renting and my options for 2000 sq feet is on or off. I can't cool one room. I can't do anything about it here but good to know it's a potential option in the future.

As for greenhouse, I'm guessing stopping frost is the primary objective.

Hi, I do not know much about geothermal but have you thought of using a well for  heating and cooling?  It could eliminate the need for all that pipe and disturbed soil.

I tripped over the same set of videos.  Hadn't found good verifier information yet either.  My guess is the length of buried pipe needs to increase in areas with warmer soils and what works for him likely won't work for me.  After all his 6 degrees translates into 42 degree F soil temps.  Mine here from the USGS site lists it as low 50's and as best I can measure my actual is between 54 and 56.

But still really intriguing.  Radiant cooling inside using simple water tubes instead of a radiator as in some of the european stuff temps me too.  400 ft of pipe buried, a low voltage dc pump and several hundred feet mounted just below the ceiling inside. It would be a pretty simple system.  Possibly need a small reservoir too to help with thermal expansion and contraction.

Now I can see how to maybe help it work even here.  I intend to have a solar hot water system added with part of it being a simple flat panel.  Now early in my cooling season or possibly before what if I circulated water to these panels in the dark?  Those nights when the air cools off below ground temperature and radiative cooling to the sky might get me 5 or 10 degrees below ambient.  I could chill the ground below ground temperature and maybe reach his temperature differential for early part of the cooling season.  Now we usually have 2 to 6 weeks in summer where it doesn't cool off enough at night to cool the house off by simply opening windows at night.  If I can suppress the soil temps early in the season will it carry me those say up to 6 weeks??  Now after that point I can probably go back to cooling the soil at night using the solar collector for radiative cooling at night.(usually smoke season so radiative cooling to the night sky won't work so best will be ambient likely)  Probably want to hold all the heat I can though as this potentially becomes part of winter time household heating.  It might also give me additional storage for almost no cost for heat during the winter.  Enlarge solar thermal to get the building too hot during the day in winter, air condition using the system storing the heat for night or for cloudy days.  Or possibly directly store the solar thermal water heat in that block of soil in winter.  Some valving or multiple pumps should allow all sorts of circulation patterns.  If I can keep it all drain back and/or buried deep enough I can avoid the need for antifreeze in the system so it would be just water for another small gain.

Don't know the answers but still dreaming and researching.  Really wish I had the water storage system from this video.  In winter use the whole thing for hot water.  In summer use half the tank for hot water and half the tank for cold water for air conditioning.  If it was combined with the inground system above pretty sure it would be effective.  Start just over an hour in.  Next 40 minutes covers the tank stuff.