Passive Heating And Cooling Via Earthpipe

Just a starter video. This one uses a fan, but passive systems have been around for centuries.

Material list in the description.

 

Was looking at some of them videos a few days ago. The Amish has been using that concept forever ,, as well as situating their houses witt the windows facing the winter sun rise .

 

EVERYTHING You Need To Know About Our Earth Tube Zero Electric HVAC System fun video of a homestead in SoAz.

How we Finished our GAHT System for a 4-Season Greenhouse

How a Climate Battery Keeps our Greenhouse from Freezing (Zone 4b) fun indoor space.

 

A greenhouse to envy - Greenhouse update (Nov). Insulation, geothermal heating and cooling, and more

 

In 1976 my Dad built a house in NC. When they were installing the septic leach field he put in 4" pvc beside thr leach pipe, and only had one 12' trench to dig to make the loop to the house. They came up under the slab downstairs and he extended one of the pipes up to the second floor hallway wall. There was a 6" to 4" adapter that housed a fan and pulled the air from upstairs and spit it out downstairs. There wasn't a huge flow, but it kept the house tolerable even on the hottest days.
The first summer we had to dig up at the end of the leach field and drill a hole in the pipe to let out a BUNCH of water, formed when the warm and humid North Carolina summer air condensed in the ground pipe. The system usually had around 12 degrees of drop, sometimes less and sometimes more. Later in life when I had pursued HVAC engineering I often thought about what would have made the system better. 6" or even 8" pipe would have been better and had more surface area. A way to rough up the inside of the pipe to introduce some turbulence and counteract the boundary layer effect would have aided in the efficiency. His decision to put the pipe in the leach field seemed, at first glance, to be just a cost saving measure but in reality was both cost saving and highly efficient as the leach field kept that ground moist and helped a lot with heat transfer. Lastly,it really needed a thermostat. Some spring and fall mornings that downstairs would be uncomfortably cold if we forgot to turn the fan off.
As a short note on the quality of things then versus things now, the fan was a 6" propeller type with a little 1/20th HP motor made by Belden and purchased from Rowan Mill Supply. As far as I know it is still there. The folks moved to South Carolina for a few years 1997, and back in 2008. They visited the people that bought the house a few times and the system was still there working.
The science and practicality of such a system is sound. Dad got lucky that the fan he bought was about the right airflow. Too much would have reduced the efficiency by the air not having sufficient contact time while underground, too little and there wouldn't have been enough air changes inside the house to make much difference. We measured his at 48 cfm, not a lot of flow but about right for 4" pipe to maintain enough velocity to be efficient.
In conclusion, he spent about $150 1976 dollars on that system and Mom about had a cow. There was never any air conditioning installed until 1997 when the realtor told them the house would not sell without it, so they put in a system for the upstairs. Who knows how many thousands they saved over 21 years.

 

A video on earth tube cooling. Looks like IA and should probably treated with caution, but has a lot of information. Explains how the system has held it back. Kind of like if your house has been using a spring for water for 150 years, you have to drill a well in order to get a bank to let you borrow money on it.



And here is a tromb wall for solar heat. The Romans used the same idea with extended roofs over porches that allowed the low winter sun to heat the wall, but let the porch roof reflect the higher summer sun. For several thousand years we have built houses with a dark brick or stone wall to the south to capture heat from the sun in the day and store it for the night.



The new and expensive heat pumps use a high tech system to draw heat from water wells, that are at the earth temp, and optimize it to hold the temp at a constant. Require pumps, refrigeration units, distribution and radiation units, all dependent on electricity, to do what could be done to get supplemental heat from an earth tube or tromb wall with very little tech. Isn't done because no one makes any money from it. Gates has made his billions by renting rather than selling Microsoft products. The heating and air conditioner used in our houses need to be maintained, powered and fueled. A very profitable business model. I heat with a wood stove and no central heat. I accept that the system is going to have about a 1 hour lag in reaching its desired temp, stove has to heat house, and that temp may vary 10 degrees from 68. In turn I use no power to my heating system. I could go to an expensive external wood boiler and a pumped system and hold an exact temp in house. I choose not to for both cost reasons, and the ability to be independent from external sources.

 

very interesting systems

 

Mother earth news had this system far back as I can remember and I'm 75.

 

Another system one can take advantage of is thermal solar. there are tons of books on it if you are interested.

 

I used to read Mother Earth years ago. Don't really remember why I quit ,,,

 

That condensation issue ,,with the water building up in the pipe was always a question that hung in my head ,,, I figured it would build up ,, possibly mold ,, then blow in bacteria in the house . I haven't read Mr Duane's article yet,,, it may address this issue,, but what do you think would remedy this possibility ??

 

I have always wanted a system like this, but living in the South humidity and the resulting condensation was gonna be a problem. Some ideas would be to have a sump at the low point of the pipe and pump out the water regularly. As for mold, place a stainless-steel cable in the pipe and run a swab through it regularly, clean it like a gun barrel.

 

The old hippies that started it sold out and it became just another slick glossy magazine. I have the back issues on DVD, and last time I checked a local library had back issues in the stacks.

 

Very similar to the passive cooling I used at the Old Cabin 40' of U shaped 6" pipe in 4 strips buried 3 feet under the cabin A vented cap above the surface on one end and a open end connected to a floor vent 4 in total with 3 floor vents in the Dining/Living room area and one in the bedroom. End vents on each end of the Cabin. As the heat rises it vents out drawing the cool air in the burried pipes up forming a natural upward draft. Kept it 15 degrees cooler on average. Tested that on a couple of high 90 degree days with vents open and vents closed. Cabin was also well insulated and always in the shade. The biggest problem with the system was it created a lot of humidity inside. To give credit where due it was my Amish friend John that suggested trying the pipe and vent system under the cabin and even helped me install it. And hey when it is 98 outside and the system was keeping inside at 80-85 degrees it made a difference.

The new place and Cabin is on a concrete slab. I have found the 6" thick slab creates a nice cool zone above the floor and ceiling fans circulate it well and help a lot in the AC not kicking on. Cabin here the original owner/builder went total overkill on the insulation and glad he did. Only use 650kwh per Month average November through April. Used 750-800KWH June through October.

LOL the barns and shop are on their own meter and we shall not speak of the bill and use on that meter when I am using the welders a lot

 

The Agricultural Engineering building at Michigan State University had no Air conditioning in the late 1960's. The grad students didn't get the best offices and they got very hot in August. They got an old copper truck radiator, a huge one, and put a fan on it to blow air thru it. Building had its own well and a drain for the sump pump. Took cold water from well and let it trickle thru the radiator with the overflow a couple feet above the top of the radiator and discharged it into sump pump drain. As little as I can remember the water temp was about 45 or so and there was no effect on the humidity, It really didn't drop the humidity in the room as the air flow was enough to keep it from condensing. It sure did drop the temp and the powers that be allowed it as it took a fraction of the power that an air conditioner would. Water temp was often 50 degrees cooler than outside air temp. We talked about using it for freezing protection in greenhouse. At 32 degrees outside aie, the water would have been about 15 degrees warmer.

 

UofA, Tucson has done a lot of work of so-called cooling towers.

Cool Towers | College of Architecture, Planning and Landscape Architecture
Evaporative Cooling Towers – 2030 Palette with pic of said tower

 

UofA, Tucson has done a lot of work of so-called cooling towers.

Cool Towers | College of Architecture, Planning and Landscape Architecture
Evaporative Cooling Towers – 2030 Palette with pic of said tower

 

Dad never got mold that we ever saw, but that first summer we had to drill a hole in the pipe at the end of the leach field to let water out. Probably condensation but possibly entered by some other means.

The system would only really get below dewpoint at night. There was usually too much sensible cooling that had to happen first. One would need literally hundreds of feet of buried PVC to get the 80-90 degree air entering down to ground temperature.

Also, I may be wrong on this, but I don't think mold will grow in total darkness, or maybe just not in PVC, because I have taken up a lot of drainage lines over the years (sewer, gutter, etc) and never encountered mold in them, even ones that stood with water in them all of the time.

 

Yep. A lot of that happening in the Southwest where there is no humidity. I have friends in Tuscon that have a ratty looking cooling tower on the roof that blows cold air into the house that rivals any AC system back here in the East. Here, they won't work.

 

Yeah, with the cool air coming into the house you have to have somewhere for the warmer air to go, otherwise the system stops working. Houses before AC had exhaust vents in the ceiling, attics, or roof to allow the warmer air to escape.