Cool tubes

harry51 · March 05, 2006, 05:34:25 PM

DW's folks live in the Central Valley in California, summer temps commonly 100 dry deg. F., in a home her Dad built about 20 years ago on her Mom's family homestead from 1862.

The house is about 2200 sq.ft., with a 1000sq.ft. basement and another 1000 or so sq.ft. loft. He has two 18" cement irrigation pipe cool tubes about 100' long buried about 10' deep running from the pasture into the basement.

The idea was to open the door to the loft balcony and create a convection air current through the tubes, through the house, and out the balcony door, cooling the house. It worked to a point, but he's since mounted a large swamp cooler on the tubes in the pasture, and turns the blower slowly. This costs very little to run (1/3 hp motor, I think), moves a lot more air through the house, yet still moves it slowly enough that the air is ground temp by the time it gets to the basement. It's comfortable inside the house on the hottest afternoons. I'm not sure if he's putting water on the cooler pads or not. (Don't think so.)

This house is very well insulated, and very well sealed, and is heated only by an antique Round Oak woodstove, which keeps it very comfortable in the winter, and the volume of wood burned is pretty modest.

JRR · March 05, 2006, 11:23:57 PM

Jonsey, good idea about the slow release chlorine tablets.

How are they placed? Throughout the tube? Or just inside one (or both) ends?

March 05, 2006, 11:48:49 PM

Chlorine isn't green! I hate it.

Of course part of the reason I hate it especially is that in Nashville I was cursed with a (city) water supply that regularly dumped chlorine into my washing machine. I lost so many clothes.

One of those ozone generating lights might not be much less green, but it would probably work about as well.

I'd looked up this topic this morning trying to find the name of that place in Georgia that was building a place with cool or "earth" tubes and underground block coated with surface bonding cement.

Doesn't look like they've updated their site since we last looked at it. And they're supposed to be open this spring.

jonsey/downunder · March 05, 2006, 11:50:18 PM

Hi JR,
I really don't know how Jim is doing it. I am hoping he will send me some more information on his system. I suspect that he just drops the tablets into the intake end of the tube and lets the fumes waft through with the air. With my system I intend to just tip a solution of household bleach down the tubes from each end (about a bucket full). This should flush out and kill any mould in the system. Most of the household bleaches and cleaning agents contain chlorine so I think it pretty much amounts to the same thing. The drain hole that I put in my tube is about 3/4" diameter and they drain into a bed of sand. The tubes have a good amount of fall so hopefully they will flush ok. As soon as I finish the hook up on the system I will do a page on my website with photos and a full explanation of the installation. I will also keep a record of how it is operating. Sorry I can't help any further than that a present but when I can I sure will, no problem.

I'm thinking as long as the tubes stay dry there shouldn't be a problem with mould so maybe if they drain as planed it will be fine without the chlorine.

Amanda_931 · March 05, 2006, 11:53:19 PM

Actually one of the oxygen bleaches might work just about as well.

Does on clothes.

March 06, 2006, 12:54:39 AM

There is a peroxide powder available as a pool supply that is better for hot tubs than chlorine or bromine that might work.

jonsey/downunder · March 06, 2006, 02:38:59 AM

I found this while checking out Amanda's suggestion on Oxygen bleaches.
http://sci-toys.com/ingredients/bleach.html

Amanda_931 · March 06, 2006, 10:33:34 PM

Interesting.

But this seems to say that acids are what release the horrible yellow gas from chlorine bleach.

QuoteChlorine gas can be released if the bleach is mixed with an acid. To prevent this from happening, commercial bleaches leave extra alkalies in the solution to keep the pH very high (pH 12). This small amount of extra lye in the solution, along with the caustic nature of the hypochlorite itself, is what eats away the cloth if undiluted bleach is spilled on the clothing.

It's possible that the horrible yellow gas is not pure chlorine, but something else, just about as noxious. In fact IIRC, it is, but....

But you do get it by mixing bleach with ammonia--or well used kitty litter. There are warnings on all the containers. Well, except the cats.

Amanda_931 · March 28, 2006, 01:40:22 PM

Speaking of cool tubes, someone on another list posted this (.pdf warning!) about a greenhouse in India where tubes are used for both winter heating and summer cooling. I haven't done more than glance at it yet, and assume it's in a near desert area, but....

http://www.iimahd.ernet.in/publications/data/2004-03-02gsharan.pdf

summer cooling would be nice, especially if it is coming from the earth--as opposed to the kind of cool night temperatures that deserts are know for.

March 28, 2006, 05:13:37 PM

In the right climate variations on cool tubes work very well and are likely to have been invented several centuries ago.

Cool tubes and earth tubes are most often used in dry climates with extremes of temperature where the soil can be used to temper incoming air. Shallow soil will be close to the average of day and night whereas deeper soil will tend to average out seasonally.

Moisture in the air or soil can lead to plant and fungal growth which can make the use of such tubes problematic in humid climates.

Links: • earthtubes used for preheating incoming air
• natural (passive) cooling for desert climates

kreech1 · April 30, 2006, 02:57:12 AM

I would first would like to thank jonsey for telling me of the new site. hi jonsey this is kurt. now for the question has anyone ever hear tell of waterproofing the cooling tubes? it,s nothing more thana mop on coating. the reason; i put my earthtubes in the ground about two weeks and it rained for about 3 days and filled 2 of the six earthtubes i put in the ground to the point that i cannot get any air to come out of them with an air hose. i,v not yet dug them back up so it could be that the earthtubes could have cracked and water leaked in. i put the tubes 10 feet in the ground well after the rain the ground settled and dropped about 1 foot in the deep end. i,m trying to get any info that would help before i dig the tubes out to fix the problem and hopefully prevent anymore kurt

glenn kangiser · April 30, 2006, 11:06:52 AM

The problem is not necessarily leakage, Kurt. Earth tubes if working properly could easily lower the temperature below the dew point of the incoming warm moisture laden air, at which time it will no longer have the capacity to carry the moisture. This means it will rain - moisture will condense in the tube and collect inside. It is necessary to put a drain of some sort at a low spot on the tube to get the collected moisture out.

You could put a drain and reservoir at the low end and a sump pump with a float to pump it out periodically as the level rises.

kreech1 · April 30, 2006, 02:11:19 PM

hello Glenn I thought it may be leakage because after i covered the tubes i capped both ends of all the tubes. i really like the idea of the sump pump.i,d like to know more about this.what puzzle,s me is how would the moisture be directed to the pump? thank you for your time kurt

glenn kangiser · April 30, 2006, 02:22:17 PM

It would take a bit of planning ahead or possibly be a bit of a problem if the tubes are already in place.

The water will naturally condense and run to the bottom of the tube --- leakage would likewise drain out the bottom. The tubes would have to be sloped when installed or you would have to find the low spot and drill a drain hole - dig a sump about a foot or more lower than the bottom- install a plastic tub or ferrocrete liner then sit a submersible sump pump with a float on it --such as the ones on sale at Harbor Freight for about $40 sometimes - in the bottom of the sump to periodically pump the water out. Leave power to it so it will take care of itself. It should be on a GFI circuit I would think. I think Manhattan could tell you if this is correct or not.

Even if the ends of the tubes are capped, you can get several liters of water out of air being cooled as it is pulled through the tubes - unless you mean that you haven't even used them yet in which case you are probably right - it may be leakage -- the sump would remove that too.

Are you in a real high groundwater area or just leakage from the excavation? Guess if I'd read closer I would know part of the answer to that.

April 30, 2006, 03:03:30 PM

glenn where do i start at? oh yeah from the begining. well to start off with i will hafta dig the tubes back up anyway for a couple of reasons 1st the tubes are side by side in the ground , found out this is a no no , i was told the tubes should be 6feet apart the 2nd thing i,v got to get the water out of the tubes and drill holes in the lowest part of the tubes for drainage. now the tubes are about 80 ft long & the deep end is 10 ft deep. and yes i,m saying that i,v not yet used the tubes as they are not hooked up(reason for being capped) glenn i do live in tennesse the ground is clay & moist so between that and leakage from the excavtion i,n mot really to sure one is the culpert kurt

JRR · April 30, 2006, 06:14:39 PM

Are you using a rigid or flexible tube?

I think rigid will be more forgiving overall. The horizontal tubes need to be installed with a slope. Septic lines are recommended to be installed at 1/8" per foot ... but these aren't septic lines, you don't need near that much if it is a problem for you. I would consider the recommendation of gutter installers ... I think they use 1/8" per 10 feet ... but keep in mind they are able to "gunsight" their horizontal runs as they go to make sure there are no low spots. Unless you use some straight edge for the tube to mount on ... rigid tube is the only way to avoid low spots in a slight slope situation.

Are you installing a serpertine layout, one that "snakes" around, back and forth? I would recommend a simple field of straight parallel lines. Unless manifolded together at the ends, each of the parallel tubes would have its own air inlet and outlet. The idea would be each tube would carry a portion of the total air ... the total could remain the same as a single tube system ... and therefore the cooling(heating) would be the same.

kreech1 · April 30, 2006, 06:45:07 PM

i,m using pvc sewer lines. i have the tubes on the side of my home going straight out. i dug one trench and put all 6 tubes in. it,s about 80 ft long . it comes to the edge of my home at about ground level. i done this because well i live in a valley basicly. behind my home i have about 5 ft of ground then a big ditch wich then goes up a very long steep hill. in front i have about 22ft and another hill steep 8 to 10 feet tall. however from left to right i have almost 300 ft to play with. my home well it,s a tralior and i thought if i could i would run the tubes in from the side having one tube per room. lloking at my place from side to side my place is almost in the middle. ooppss i meant looking.

Amanda_931 · May 01, 2006, 12:25:21 AM

Not quite sure if I'm visualizing Kurt's tubes--are they going up the hill--underground but up from his trailer? In that case, shouldn't have filled with water without you knowing about it. Or did they and you did?

I'd think that, depending on what kind of soil you have there, backfilling so as to protect the joints in your tubes would be really really important, maybe tricky, that a hard rain might well have shifted one or more. (and ouch! 10 feet down--be careful!) sand bed around the tubes, to try to cushion them, maybe. That Georgia park went through changes trying to get their long runs down in the ground without either killing someone or breaking their pipe.

These links have been here before, although I think the AGS (greener shelter) has some new text.

http://rmrc.org/shopping.htm

(first chapter of the (old) PAHS book is still free, but it's hosted on some gaming site--it worked)

AGS does (among other things, I think) underground tubes, with heat from--in the diagram--the gap between roofing and sheathing, but they are trying to stabilize the earth temperature under the insulation blanket--also for year-round conditioning of the air in the building. I think this article is new--mention of, not links to Australian attempts which might work better only a little farther south than here.

http://www.greenershelter.com/index.php?pg=2

glenn kangiser · May 01, 2006, 12:26:28 AM

I think the solid tube is good too - more slope is better if you can do it - cool air gets heavier and wants to go downhill (think cooling tower) so the low end and drain should be toward the house with water somehow diverted away at the bottom or pumped out in my opinion - fan powered air through tubes, then, near level is not much problem. I was thinking of putting some up a sloping hill and using convection - probably wouldn't work great though-- experimental stuff. The cooling tower is used in the middle east and is reported to work. I haven't seen one in operation personally.

Amanda_931 · May 01, 2006, 12:44:10 AM

The Middle Eastern cooling towers work like a swamp cooler--water sprays into it. No good for here. But maybe for you.

May 01, 2006, 01:36:27 AM

It would work fairly well here - fairly low humidity and high heat here in the summer --- dry heat -- it can be 112 degrees but only feels like 111.

kreech1 · May 01, 2006, 06:13:24 AM

hey amanda wow your neighbor from tennesse myself. if you would like to know where send me a pm. my pipes in level ground but it slopes down as the pipes get further from the trailer. hope that help,s no i didn,t know that it would fill up with water .but i also didn,t put a drain hole either . i have thought a bout putting a bed of small rocks under the pipes about a foot deep. you asked about the soil it,s like moist hard clay. yeah 10 feet was deep but when i first started i didn,t know 1/4 of what i know now. i went into to blindly after the pipes broke that,s when i really started using the net to to find out as much as i could it took awhile i didn,t even know that this even had a name (cooltubes or earthtubes). i also just bought a copy of john hait,s book hope that will shed some more light. thanks for the web sites amanda i wiil look over them . oooppss sorry about that we are neighbors amanda, i,m in tennesse also kurt

Dustin · May 01, 2006, 01:13:10 PM

Speaking of wind towers, a couple years ago I went on a Solar Home tour in Tucson and one of the homes was Rich Michal's featuring a cooling wind tower. It was not up an running when we were there, ut it looked interesting.
This link will take you to some pics and info on his house:
http://www.terrain.org/articles/16/michal.htm

The house had some neat features, but the man really needed an interior decorator because all the exposed concrete interior was far too industrial/modern looking for us.

Sassy · May 01, 2006, 01:59:03 PM

I see they used rammed earth for their walls - that can be very beautiful. I couldn't find any interior pictures but here is another link that obviously (at least to my taste) had an excellent interior decorator... (as well as architect, builder etc) 8-)

http://www.terrafirmabuilders.ca/Portfolio/landscape.html

John Raabe · May 01, 2006, 07:05:16 PM

I find photos like this to be very exciting. Oh, to live in a climate where this kind of thing would work!

At one point in my search for a place to live I almost settled in the New Mexico, Santa Fe area because you could make curvy handbuilt things out of mud.

In the North (and particularily the NW) things have to be made out of wood and insulated from the wet and cold. This kind of construction would always be damp and cold. Kinda like spending a winter in a stone castle on the moors of Scotland - that'll make ya pull down on ya kilt!

Now, you could always spend piles of money on spray foam insulation and stucco to protect it - but that kinda spoils the whole earth connection thing don't ya think?