Thanks for the link to the pdf of the book Amanda; it's one I missed. I wouldn't mind the link to the discussion group you mentioned if that's possible.
Glenn, I have started this as a new topic in the general discussion in case there are a few more ideas floating around.
My plan for the cooling tubes is pretty much along the lines you suggest. The system will be an open loop, with the open end under the house. If needed, I will install a blower on that end. The tubes will vent into both bedrooms and will mainly cool that area. Through the summer, the temps in this area are mostly in 40's, the night temps are only a few degrees lower. We use what you guys refer to as a swamp cooler now, works great but is noisy, uses a heap of water and power. There is no provision for such a beast in the new house so even if we can get a bit of free cooling it's a bonus.
The tubes are 150mm-storm water pipe and will slope away from the house. There will be a drain at the lower end with a sand bed under that. I will install a pull through system in the tubes as I go. There will also be provision for flushing. The humidity in this area is between 30% and 50% through the summer so I'm hoping moisture will not be too much of a problem. There will be two 40-meter loops buried about 1.5 meters, I would like more but room on the block is a problem. One bonus we have, the ground stays moist at a meter down, this will help with the cooling.
The tubes will just be a part of the passive cooling setup and will complement the shading, ventilation and landscaping design of the house.
The vents in the cathedral ceiling work quite well for now. I will, be looking at some kind of solar chimney later on, maybe incorporating a heating system there as well.
jonesy.
I intend to try something similar (in southeast USA), but I have been thinking of a once-thru uphill system. Electrics will be buried with pipe for a pusher fan if necessary.
Look here it may be near enough for you to check out in person.
http://www.solar.org/
Thanks. Fairly close by. I'll try to give a visit this summer.
Hmm. Never heard of those guys. Somehow I thought it was going to be Sequatchie Valley. So now I'm reading about cool tubes in the South-east. Something I'm really interested in.
Cob list
ESSA
ESSA2.
The first two do have archives, not sure if they are up yet for the third--lost the lovely University server. I never use the archives, just search for the topic, generally find myself going on and on.
Has everyone seen this link?
www.greenershelter.com
This is Don Stephens' web site. He calls his system AGS--annualized geo-solar. Get your tubes down far enough (and don't run into ground water!) and you end up doing your exchange about six months later--so, cool inside in the summer, warm in the winter.
He does say, on the web site, that the slower the better on moving the air through the tubes because you want the air to have given up all its temperature differential before (as would be the ideal) it reaches the other end.
(The other year-round version is PAHS--John Hait--the .pdf link posted earlier. He claims to have a new version of his twenty-year-old book out, but I'm not the only one who wonders if color pictures is the main difference. Right now you can get the new one as a .pdf file for $50.00, and the old one in print for $49.95--probably plus shipping. The ESSA (2) list is whining about that right now.)
Mike Reynolds wrote something about just cool tubes in an early book that I no longer own.
I wonder if any of the "cool tube" (aka "earth tube") experimentors plan to insulate the pipe as it passes up through the near-surface earth? It seems to me if they fail to do this they will have lost some of what they went so deep for. ???
Yep.
Hait especially, put insulation all around his mostly underground houses, and out for many feet around the house. Stephens not quite so far out, only about six feet or something.
I think Reynolds had his tubes going mostly down, so it didn't apply so much. (It would to those of us in the east)
Read this link and the earlier ones. Got interested.
Followed all the links and found some other ones. Wound up on some DOE sites.
Conclusion that I drew. Need a chimney. Chimneys are expensive, inefficient, and design unknown.
Earth tubes are a great idea. Design unknown.
Too many variables. Earth temps vary too much...even at the same site...to engineer a standard.
And, remember, we're in an area where the night/day temps vary 40-50 degrees.
Have I missed something? :-/
Let me know, cause we'll pour the slab in < 30 days.
What I'm thinking now is that we'll just plod along, building for solar gain in winter....doing the the things that are recommended for summer...plugging all the air leaks like we always do.
We are thinking about a plumbing system that will allow us to circulate the RIH water to the cold night air and cool it the slab that way. That seems to make sense to us.
There is a house near here with radiant floor heat with a big storage tank - I would guess 2000-3000 gallons. Are you using a storage tank, Shelley? Just wondering about how your system will be set up. Seems to use it for cooling you would need storage to hold the cold. Would you use radiators of some sort to exchange slab heat for air cooling ???
It won't work for me here as nights are about 80 degrees f. for several weeks on end.
Are you putting pex in the floor no matter what? I put it in 3 sections to play with-
Hi Shelley,
That's pretty much the research that I ran into on the web. There is screeds of stuff along the lines of "the therory is great but there are all these problems blah, blah blah."
I am working on the principle of "suck it and see" and have gone ahead and put tubes in the ground. I figure what the hell, if it doesn't work, I'm out a days labor and a couple of hundred bucks.
I took some ground temps at the bottom of the trench and found them to be around 21dgr's. That is about what I would have expected based on my research of the mean average temps in this area. We are just coming out of our summer with temperatures of around 40dgr's plus. The last month has seen temps around 35dgr's. The climate in this area is very dry with an average humidity of between 30% and 50% through the summer. It would seem that around 80% is where you would expect to have problems with the system.
When I installed the tubes, I put a slope in the pipes with a drain hole at the lowest point. I have a soaker line running on top of the tubes to keep the ground moist and the pipes are run under garden beds. If you can keep the system in a shaded area and the earth moist you would expect better cooling.
I think most folk expect the earthtubes to work as a full on air conditioning system, and when it doesn't, see it as a failure. It should be looked at as part of a whole passive system, along with shading, insulation and all the other things needed to keep the house comfortable.
At this stage, I will not bother with the chimney and will simply install a couple of small fans to push the air through the tubes. These fans don't need to be that big, as it's only a small amount of air going through the system. The slower the better.
With our tubes I am expecting to use them solely as a cooling aid, the heating is not a problem around here. I can't say at this time if it is all working as planned but will certainly keep you all informed as we progress.
jonesy
Shelley,
Just thinking about your idea for night cooling. I remember reading about a guy over here that lived up in the Simpson Desert he used something similar to keep his beer cool. It was an old fridge turned on its side and opened to the night air (I think he had some sort of reflector on it). The door was closed in the morning before the sun started heating everything up. The night temps in the desert drop almost to freezing, through the day they can be up to 50dgrs. I see no reason why you couldn't build something similar, maybe with some tubing coils inside. I think the article was on a solar box-cooking site.
Our head researcher may be able to dig it out for you. ;D
jonesy.
Going to put the PEX in regardless. But remember this is metal building/shop/guest quarters.
We've had RIH for years in several houses. Weren't going to bother until we built the house, then thought what-the-hey....why not?
Idea for cooling not fully formed. But since the mechanicals will be in the shop we can figure that out later....as long as the rough-in is there.
There's a company back East that's selling a package for doing it. Way overpriced. Combo of pex running underneath metal roofing. Can't tell from the pics how they're protecting the pex from the screws. Don't know how we'll do it yet. Just need some way to exchange the warmer water in the slab with cooler water from outside. Stop the process at daylight.
One of the solar guys here who's building a house is doing a simpler system. He has several columns designed in his house. Just DW rectangles holding water tanks. Will circulate that water to the roof at night to a panel. KISS.
I'm sure that whatever we come up with will have to be suplemented by evaporative cooling in the afternoon. We don't have enough mass in the metal building. But if it works somewhat, we can transfer the idea to the adobe house. With our temp drop at night, seems like a reasonable idea.
Jonsey,
No shade here and no damp earth either. But don't I remember an old MEN article maybe in the 70s? Home built house in the CA desert. He did something like the cooling tubes. Think he had some kind of chimney too...tho at the time I didn't realize what it actually was.
I just typed the worlds longest reply- hit the wrong button and it's gone.
Are you insulating the roof, Shelley? If not, you can fasten to the purlins with single SD screw clamps - If insulating you could put pex above the insulation. We used 2" UL Vinyl covered insulation years ago sandwiched between insulation and purlins.
Switching could be done with a solenoid on one side and a reverse flow check valve on the other side to prevent back flow to heater - both sides of cool line tee'd into the heat line. If done right you could use the same pump for heat and cool. A cheap timer could control the cooling system.
Sounds like you are pretty much on to it Shelley. A solar water heater will work in reverse. All you need to do is divert the hot water during the day or cover the panels to stop the daytime heating. There is a forum on alternative air-conditioning that discusses these systems; you may pick up some useful tips there. Amanda will probably be able to provide a link for you.
The shade I am talking about is more insulation than shade. This is simply provided by running the pipes under lawn or garden beds. Normal watering of same provides the moisture. I have the added insurance of a soaker line buried with the tubes. I think the odd short burst of water down the line through the summer will assist in keeping the ground from drying out.
Just diverting a bit here. NSW has recently introduced new building codes that come into force on the 1st of July. All new homes will need to comply with water and energy saving guidelines. There is a list of measures suggested to assist in complying. This has caused quite a stir with the local builders. I am hearing stuff like "woe is me, this will put us all out of business, the cost of building a house will go through the roof". It seems that most don't understand that these measurers are simply a matter of good planing. There is no reason that good passive design should cost any more than the normal building costs. Things like, proper orientation, eaves that are designed for local sun angles and insulation will take care of most of this. A few others are, good landscape design, thermal drapes and light colored or reflective roofing. Mostly you need to have a reasonable understanding of the local climate.
A good example of poor planing, is a home not to far from me. The climate in this area is arid and hot. The summertime temps are constantly in 40s, at night the difference is only a few degrees. There is little rain, about 400mm per year. The winters are mostly mild although we can get some cold southerly winds. The area is mostly flat treeless plain.
This house is your typical Mac mansion. Two story brick veneer, no eaves and a black tile roof. All the large windows face the south, because that is where the view is (sun is in the north down here). The house is built in the middle of a large open paddock (no shelter from the southerly winds) The landscaping is typical English garden, all lawn and roses (needs a heap of water). I would bet that the only insulation is the foil building paper. Basically, what you have is a large brick sitting in the middle of the dessert. You can imagine the cost of running that outfit. ???
OK now that I have had my daily grump, I'm off to fix mothers' bike.
There you go Glenn, bet you don't know what I will be up to on Sunday. ;D
jonesy.
BTW, since I am too lazy to convert the metrics for you, here is a conversion table to translate into American. A bit agricultural, but near enough to get an idea of what I'm on about. You can save it to your desktop (feel free to improve it if you like).
http://users.tpg.com.au/jonsey/Conversion%20Table.xls
How did you know I was going to give you a bad time about the metrics, Jonesy ??? Can you foresee the past ???
Okay - thanks for the conversion table - they were trying to teach me metrics in school and telling me how much better they were than our system, but I just chased girls all night and slept through the classes :-/
I guess that's what I get-- have to convert with a chart. :o
Crikey, Jonesy. That conversion chart's a beauty. You must be way ahead of me in Excel. I can usually get it to do what I want but never did find all those pretty colors. I use it mostly for estimating. ::)
I dunno mate? Not only are we pretty, but geniuses as well. Now that could spell trouble. ;D
jonesy.
Hmmm. I don't know anything about an alternative air conditioning forum.
But it sounds like it might be wonderful--or full of people with bees in their bonnets whose ideas range from the "won't work in the humid south-east" to "pretty goofy."
No-electricity ways to make your house friendly to people allergic to lots of things is on my mind right now.
But I think I'll keep the cats and dogs.
I found the air-conditioning forum while looking for stuff on the cool tubes. I didn't keep the link to the site though and a quick search since hasn't turned it up. There seemed to be a lot of knowledgeable folk from all over on there with a heap of ideas. I think it may be well worth looking for. There was a lot of information on making standard systems work well and quite a few home built systems as too. If I get time in the next day or two I will try to find it again.
jonesy
I'm a couple of pages into a search (the greenbuilding forum isn't turning up for some reason) but I did find this--huge, deep, long tubes with drains, powered by convection (solar) chimney. A pretty far cry from what those guys in Georgia are doing, but you are SOL if you're building on a lot, or in the woods, etc.:
http://www.i4at.org/surv/aircond.htm
Could you just not drain your cool tubes and run a circle with your pipe through an air-to-air heat exchanger, cooling your room air without exhausting it, sending the cool tube air back underground?
Couldn't use solar chimneys (or wind scoops or whatever we're going to agree to call them) if you wanted to keep the mildewy air away from the building, I guess, but....
Underground air needs to go as slowly as possible. Would that be a problem?
I don't see any reason that you couldn't hook the far end of two tubes together and make a closed loop, Amanda, with a fan on one side to keep flow in one direction. Then you are not fighting cooling massive quantities of outside moist air, so no great amounts of moisture to deal with - may work as a dehumidifier if you have a small drain to get the water out of the tubes.. Sounds like it's worth a try. You probably wouldn't even need the heat exchanger if you kept the intake and outlet in separate areas of the house to move cool air throughout and prevent short circuiting the air from outlet to intake.
Amanda, I found that link.
http://groups.yahoo.com/group/solar-ac/messages/421
There are a couple of methods that you could use. One is the open loop like I am using. Another is a closed loop. This is where the air is drawn from inside the house and pumped through the tubes back to the inside. There is also a heat exchange system. With this type, the tubes are filled with water, which is continually circulated through the pipes. A heat exchanger is placed in the system and can be incorporated into your standard ducted heating or cooling system.
This site is worth looking at, this guy has quite a few pages on cooling and heating ideas.
http://mb-soft.com/solar/index.html
Thanks for the links, Jonesey.
The idea of the heat exchanger would be so you wouldn't have to have spore-laden underground air in your house. Just the house air recirculating. You'd have to deal with ventilation separately.
That one link was suggesting that huge corrugated pipe that we use for culverts. Almost impossible to drain completely.
I have a variation of the "earth tube" idea I've been playing with. I have a country property, now within city limits, that has an old house and an old dug well on it. The house needs much work and maybe it'll get some this year.
The dug well needs cleaning and I will probably pay someone in the business to do this for me. Where allowed, new wells installed in this general area today are often bored by machine ... to a diameter of 24" (I believe). My local municipal restrictions no longer allow well-water use except for outside use and heat exchange. Water can be expected at 50', or less, depth.
Therefore, if the well is reconditioned, it could be a source for gardening water. And ...
If a capped-off (say, 12" dia) pipe were installed to several feet vertically below water surface .... with a small furnace-type condensate pump inside at the lowest point .... and a smaller pipe (say, 8" dia) were run down inside to within a foot or so of the bottom of the larger pipe ... would this all make for a "conditioned" air source? Down the larger pipe, return up the smaller pipe?
Advice?
I'll bite on this one, JRR.
I drilled wells for about 10 years. A variation of the method you are talking about is usually done with two wells -one for cool water and one for disposal of the water after the coolness or heat is taken from it by a heat pump.
It sounds to me like you are talking about a version of a swamp cooler recycling air down two pipes in the well - I don't know how well that would work - once all the air was saturated with moisture you would loose the cooling effect it seems. The well water being fairly static may increase in heat. Water in the heat pump situation is considered degraded if not by contaminants at least as to temperature.
If you are adventurous you can clean the well yourself with a 3 or 4" light wall pipe with an elbow on top to direct the flow and a 3/4 to 1"air line going to within a foot of the bottom and a winch to raise and lower the pipe. The air line goes into a elbow welded onto the side of the larger pipe making an air lift pump that can be used as a sort of dredge to clean out the bottom. If you have an interest in this let me know and I can get into more detail and specifics with you. Be sure to check back with me for more details as it is possible to get hurt doing this-- just common stuff for well drillers though.
Glenn, thanks for info. I value your insight.
My pipe-inside-a-pipe is nothing more than reconfigured "loop". The concept would be: Filtered atmosphere would go "down" and atmosphere would return "up" ... hopefully with less water vapor and at a different temperature.
But your comment about the well water becoming contaminated with heat is interesting (disheartening, but interesting). I was hopeful that even a single shallow well would act more as a "perfect" heat sink.
Not only is there no "free lunch", ... there's no "reasonably priced lunch"!
Geothermal heat pump....that is one thing we looked at since we will already have a well. It is a closed loop system so no pollutants get discharged back in to the groundwater but there would be a temperature difference. I don't imagine it would make a difference given the amount of water below ground. Here are some different configurations: http://www.fhp-mfg.com/geothermal/geothermal.htm
This can be used for heating and cooling.
I think the amount of heat being put into the well could affect the temperature of the well in varying amounts. If the water underground is flowing -which is not real common then there may not be much change. When a well is being pumped you create a cone of depression in which the bottom of the well becomes like a low pressure area and everything flows toward it. Opposite that if you are putting heat into it the hottest point will be the well itself and the heat will have to dissipate in all directions. Maybe it would go away fast enough- maybe not. There are many variables.
Reading the above site it looks like they have taken this into consideration -maybe even have a track record. ;D
Jonesy-- any progress report on the cool tube experiment ???
Not yet mate, I have been a bit sidetracked over the last few weeks. We have had some decent rain here and the cockies have been breaking tractors flat out, so I have had to do some real work for a change. It's been a bit of a holdup on the building work. I have managed to get some of the deck on and will be updating the page in the next week or so.
jonesy ;)
Glenn, as I was reading thru Jonsay's posts I too was getting ready to jump him about the metrics when I got to your last one and you beat me to it!
Thank god, he had sent me his conversion program a few months back so I was one step ahead but still hated to pull it up to convert! How lazy can I get? Yeah, I know, pretty lazy!
Just have one question for Jonsay..how do you keep the guann's out of the buried pipe? I think you are talking about an open ended pipe that comes out of the ground at some point to take in hot air, pull it thru the tubes and discharge it into your house? Here in TX we have a LOT of snakes and you'd be amazed at the small holes they can get thru...how would you keep them out of the tubes and eventually your house? I'm thinking some type screen but, not coming up with anything I'd feel really save with. Also wonder how you drain the condensation out the inlet if you have like a 90 degree ell coming out of the ground...am I missing something here?
Okie Bob in Texas
Hi Bob,
Good to hear from you again mate. I have a blue heeler tied up at the entrance to the tubes and I reckon no goanna is going to mess with him. I think we should be safe enough there.
Na! That's a fib. ;D
There will be a mesh screen over the end of the tubes and they are sloped away from the house. I have a couple of holes drilled at the low point and have put a bed of sand around that area. Moisture shouldn't be too much of a problem as we have low humidity out here.
BTW I found a couple of mistakes with the conversion table I sent you; there is a better version on the index page of my website if you want to update.
jonesy
I don't have much experience with cooling tubes as I'm living in an area where there are only a handful of days a year when the thermometer reaches past 90ºF and then the night usually dips down into the high 60º's.
There might be two nights a year when we don't sleep with a blanket!
At any rate, here is a link for a somewhat elaborate passive air cooling tower.
http://millennium-ark.net/News_Files/INFO_Files/How.To.Stay.Cool.in.Desert.html
Simplified versions of this have been used in the Middle East for centuries. Usually there is some type of wind scoop on the roof pulling hot air out on the leeward side of any breezes (some modern metal ones can rotate while older units are fixed masonry). Then, below at a window on the shady side of the house, incoming air is run through a screen or cloth that is moistened by dripping water.
This is similar to some I saw in Iran and the kids usually had the job of keeping the water reservoirs filled.
These can work quite well in climates where the air has low humidity.
I was just thinking of adding one of these to my cabin yesterday- I'm at a point where it would be easy to incorporate into the front corner and let it exhaust out the greenhouse above (for a solar chimney).
I want something that works in high humidity, sometimes a lot of hot weather, and maybe not much in the way of breeze.
(I'm afraid it's called a noisy AC unit I've already started this morning (it's for the dogs, of course!)
I do know of someone in West Virginia who has PAHS--the passive annual heat storage. The person who sent me the air-to-air heat exchanger plans (that I could forward). Haven't heard from him in a while, but I recall that he thought it worked pretty well.
Yes, AC is the answer to high humidity cooling. :'(
Refrigeration has made a huge difference in where people can live and where they choose to move to over the last 75 years. (Think dusty Phoenix in 1910).
Seasonal heat storage is doable but very expensive. I have never seen a system that even came close to having a realistic payback. Some of it is just hard work, so if you have a source of free labor (you?) then things like earth tempered air exchange systems can be effective. Especially in dryer climates like Jonesy's.
Some of these conduction systems seem to have problems with drop off efficiencies — that is they don't work as well the third year as they did the first. This may be due to seasonal heat retention in some types of soils.
The ones that really work are higher density water storage systems in insulated tanks. With enough money you could build a house that is 100% solar heated and cooled (run the pumps on PV).
You can also run your AC on solar panels for "free" too ;), and maybe someday that will be cost effective.
John, I believe you are right on about A/C in humid climes such as E TX where I am building. Glenn and Jonesy don't have the humidity problem Amanda and I have!
For me, I just had Icynene sprayed under my metal roof and inside all exterior walls. Then as soon as I got the sheetrock on the ceilings, I turned on my small window unit and viola! nice and cool. In fact, I turned on the window unit and left for the night, came back in the next morning and was surprised to find I could hang meat inside! Course I'm only talking 16X24 living area but, found I had to turn the A/C down to the point it barely uses the compressor and when it does, it produces enough water flood the yard and should provide enough for a garden! Course that was a day with 100 degree (F) and about 90% humidity.
I did insulate the entire under-roof area...about 50X24 and the cost was $2768. NOT a DIY project as you can't even buy the material unless you have a license with the manufacturer. Can't say enough about the benefits of this product and would be happy to expand on it if anyone is interested.
Okie Bob
How thick was your insulation and other relevant information, Bob. No goanna problems I assume ???
Sounds great at any rate, Bob. ;D
A great example of the power of good insulation!
When you build a smaller house, and then insulate it well as you have, it really doesn't matter where you put in your heating or cooling - and it won't take much of either.
The better a house is insulated the less incentive you have to do some expensive alternative heating or cooling system.
You can hold your head high even if you are using electricity for both heating and cooling as you will only be sipping the juice lightly.
One mistake I see sometimes is that someone will build a small well insulated house and then spend $10,000 on a super efficient radiant, geothermal or other alternative heating or cooling system.
Such a place can likely be heated with two electric baseboards and cooled with a $100 window air conditioner. And, because good insulation (and good windows and doors) give you a uniform heat loss barrier, the temps will be about the same everywhere in the house no matter where the source is located.
Expensive, high-efficiency heating and cooling systems usually only make economic and comfort sense in INEFFICIENT or VERY LARGE houses.
What John says is absolutely right. And it kind of works in reverse as well. A small amount of heat or coolth can make up for terribly inefficient structure as well. Like my 2" of fiberglass, a lot of single-pane, mostly louvered windows.
I expect that I will go ahead and insulate well, even the main room of the guest cottage. Although it may mean that I will sleep out on the screen porch most of the year.
Friend of mine thinks that icynene is wonderful. I refuse to have it around until I get positive assurance that there are no isocyanates in it--"poly-" or otherwise.
It's probably fine for most people who haven't worked with automotive paint, not even everyone who did back in when the formulations had a lot of it ended up sensitive to it, not even sure that I was, although the doctor at the time thought it fairly likely. Once applied--they occur in the blowing agents for icynene--they disspate rapidly. Once the stuff has dried, no problems even with someone deathly sensitive to it.
But I did make a heck of a lot of trips to emergency rooms and doctor's offices when I worked where the non--painters got worse doses of paint fumes than the painters (the rules were such that only the paint booths were subject to remediation and prevention).
I think you lost me, Amanda-- With a small amount of heating or cooling in an inefficient structure, won't you still be excessively hot or cold ???
A related question about super insulated spaces: what about air exchange? If air can't infiltrate/exfiltrate, sooner or later the air is going to go stale and there will be humidity build up from occupants and their activities. As an asthmatic, this concerns me greatly.
I think when you have successfully stopped nearly all sources of air movement you open windows and doors for fresh air- especially when you hear someone say, "Who stepped on the duck?" :-/
Yes, good levels of insulation will likely mean some kind of controlled ventilation. In mild weather it can mean cracking a low and high window...
In very cold or very hot climates air sealing (http://www.mme.state.va.us/de/energybook/hbchap2.html) and air to air heat exchangers (http://www.warmair.com/html/air_to_air_exchangers.htm) can be worth the investment. For folks with allergies controlled ventilation can also mean filtered, and UV sterilized air if needed. (http://www.lightyears2.com/FreshAirPump.html)
The alternative is, of course, uncontrolled ventilation —which can have a whole host of other problems in severe climates.
In mild climates, who cares?... Just throw another shrimp on the Barbee. :D
I guess the lesson here is that you have to be more anal-retentive in a severe climate. Maybe that explains the Scandinavians! ;D
Maybe thats what my uncle on my moms side was talking about-- the family came from Sweden and settled in Wisconsin. He said Wisconsin winters were so cold you had to wet the bed just to stay warm..... but that was in the old days before the had fiberglass insulation etc. ;D
Great followup posts everyone!!! And Glenn, I believe Jonsey has the goanna situation under control, at least for his 'cooling tubes'. Still not sure about the potential moisture problem he may have?
Glenn, I had 4" of Icynene blown under the metal roof and filled the 2X4 stud walls with the stuff. Not only is it great for temp but, also for noise control. I have an air compressor in the garage, right on the outside of the inner dividing wall and can't hear it running with the insulation. My wife is a bit unhappy as she loved the sound of the rain on the metal roof and now can't hear it at all!
One other point the contractor told me was that they recommend completely sealing off the attic area...no ventilation at all. I already had a power vent installed in the gable end and vented Hardi Board soffets on all four sides. He wanted to insulate off the soffit vents and close off the power vent fan and build the dividing wall between the garage and apartment all the way to the metal roof and insulate it...completely closing off the attic.
He had pictures with electronic thermometers reading the temp above and below the ceilings with 1/10th degree difference!!! In my current home I'm guessing the temp difference between the living area and attic something on the order of 40 degrees F (again for Jonsey). I thought that was pretty remarkable.
The place has been closed off all week as I have been in town working. Can't wait to see what the room temp is like when I get back down to the lake this evening!
Okie Bob
Let us know how this works out. There are some good arguements to be made for the elimination of attic ventilation and cathedral ceiling ventilation when air sealing can be counted on to block the delivery of moisture to the framing. Icynene can do this.
Most code inspectors have to be convinced however, and some parts of the country could be more problematic than others.
I thought I might share this with you all. At this stage my tubes are still not hooked up or operating. I am hoping to get onto them in the next couple of weeks so it shouldn't be long until I can give a report of my own. The second e-mail was interesting in that I hadn't realised we could be eligible for carbon credits.
-------- Original Message --------
Subject: Cool tubes
Date: Mon, 27 Feb 2006 14:40:23 +1100
From: Jim Mcknight <e-mail addy removed for privacy>
To: <jonsey@unowhere.com.au>
Hi, thanks for your very interesting page. I've been following it with interest and was very taken with your discussion of earth tubes.
By way of reassurance, cool tubes do work, amazingly well. I owner built a 700 m2 house near Sydney with six 250mm cool tubes. With the help of the University of Athens SUMMER programme I modelled my site and calculated that I would get 82% of my cooling in lines only 30 metres long. I buried them in a radial spread 3.5 metres deep in clay which has a year round 18.2C subsoil temperature. I have abundant cooling, virtually no refractory period and can keep the house at any temperature from 24C upwards effortlessly all year round. We completely aircondition our huge house for an overall cost of $15.60 a year the cost of running six blowers.
A problem though is that cool tubes are wonderful dehumidifiers and that with high dehumidification come all sorts of moulds etc. To combat this I use slow release chlorine tablets which knock this stone dead. When working gives a very faint ozone smell in the house which is quite pleasant. A handful once a season does the job.
Thanks once again for your excellent journal.
Jim
Subject:
RE: Cool tubes
From:
"Jim Mcknight" <e-mail addy removed for privacy>
Date:
Wed, 1 Mar 2006 10:18:18 +1100
To:
"laurence/jones" <jonsey@unowhere.com.au>
Hi Jonsey, make sure you claim greenhouse carbon credits for your
system. This will return you a healthy dividend when you sell them to
Rheem or the other water heater mobs.
In haste, Jim
Great to hear from someone who is actually using it and it is working. That is a monster house-- rough guess in my head conversion - I would say over 7000 square feet.
Thinkng about this a bit -putting the cool tubes up a hill sloping toward the house would assist the fans as cool air is heavier than warm air -the falling would pull more warm air down with it like a cooling tower. Moisture would drain toward the bottom so a drain could take away the water to a collection tank or irrigate a garden.
Won't help much if your land is flat as a pancake, eh, Jonesy-- but then again you could construct your own small mountain with enough room and machinery. :)
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.
Jonsey, good idea about the slow release chlorine tablets.
How are they placed? Throughout the tube? Or just inside one (or both) ends?
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.
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.
Actually one of the oxygen bleaches might work just about as well.
Does on clothes.
There is a peroxide powder available as a pool supply that is better for hot tubs than chlorine or bromine that might work.
I found this while checking out Amanda's suggestion on Oxygen bleaches.
http://sci-toys.com/ingredients/bleach.html
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.
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.
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 (http://www.thenaturalhome.com/earthtube.htm)
• natural (passive) cooling for desert climates (http://www.azsolarcenter.com/technology/pas-3.html)
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
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.
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
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.
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
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.
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.
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
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.
The Middle Eastern cooling towers work like a swamp cooler--water sprays into it. No good for here. But maybe for you.
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. :)
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
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.
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
(https://i36.photobucket.com/albums/e44/kathykrn/foyer.jpg)
(https://i36.photobucket.com/albums/e44/kathykrn/northentrance.jpg)
(https://i36.photobucket.com/albums/e44/kathykrn/terra65.jpg)
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?
It's my understanding that rammed earth can be used pretty much anywhere, as long as you have a good roof overhang (a wise design concept for all houses, in my opinion) and a good concrete foundation. It's strength usually comes from concrete or plaster of paris admixture.
I absolutely love rammed earth and cast earth walls in a house, and would love to do one. The cost is just astronomical though. I looked into it and the only folks that do it want to build houses in the $600,000 and up category. I even considered hiring someone to just do the walls and leave me to do the rest, but they still wanted so much money it wasn't even worth considering. Maybe one day when I hit the lotto.
The Michal house does have some rammed earth sections (not complete walls), but uses a lot of exposed concrete block that looks pretty fugly. I'll have to find some of my pictures when I took the tour and scan them- I forgot my digital that day. I think he could fix the stark home with a little warm earth plaster (like from American Clay). Some color and depth is all that is required.
Dustin - you're doing it wrong -- dirt is free. Don't ask a contractor. Get the rammed earth house book by David Easton.
Drier than mud - a few percent cement if necessary - check your soil per book instructions -make friends with it --get to know and love it. When you and your soil are intimate you are ready to start building with it. Play with it --test it -- make mud with it -- add sand, straw or clay as necessary. It's not rocket science - its mud -- Eastons book will tell you how to make bond beams and pillars - cement columns or wood can be used between them. It will be expensive if you let others do it but Afghans and people all over the earth have used it for centuries because it is free.
I got a used pneaumatic rammer for $250 from a rental place - for slow - a 30 lb rock on a stick will do.
Your choices are huge when working with dirt.
Cob (sand/straw/clay) so time-consuming that people have done really creative work with design. Michael Smith, Ianto Evans, Becky Bee are the standard authors. I've recently gotten one by a British pair who studied with them and does just gorgeous work--more info later.
Earthbags (now there's a good use for plastic). I really like what I've seen of earthbags--especially the Hunter/Diffmeyer book.
Cinva Ram (addresses for machines and plans available at www.dirtcheapbuilder.com). It and has been used for generations now in Latin America. Similar machines in India.
Other rammed earth blocks--the hydraulic machine made usually don't have to be cured.
Adobe (called "mud" in Australia, what Cecelia and Jonny used)
the Easton rammed into forms style
Underground.
Living roofs
Probably more as well. In fact I know there are more, I've been reading a not-very-new book by Gernot Minke.
The other earth-bag guy, Nadir Khalili of Cal-Earth, invented/re-invented or something, a fired-in-place ceramic style (The fired brick kilns he found in Iran were made of unfired brick, and had fired, probably neither evenly nor well, after years of making fired bricks).
His book on the subject has a lot about domes and vaults in it, by the way, so even if you've no desire to build a mud-brick house then put a huge fire in it for days to turn it into fired ceramic, it may be valuable.
I know someone on-line who took a course at Cal-Earth, built part of his house as an earthbag dome.
But a friend of mine cautioned that sometimes "free" wall building materials end up expensive because all the other systems (and sometimes just the fasteners) end up costing more because they are not well integrated into the design--sometimes cannot be integrated into the design--running conduit into a fired ceramic house?? Choice of ugly or forget everything above baseboard level?)
Glenn-
You're right of course. I do have the Rammed Earth book and several others. I can certainly try to do it myself. But I'm not quite confident enough in my abilities to attempt to build a full scale primary residence of rammed earth walls in town (and get it to pass code) with all the room and systems for a growing family of 5, which is what I need to do for my family. This is why I looked at contractors to build the walls and consult with me on how to get the various required systems for a modern home in an unconventional building system and pass code. It was just too costly even for bare bones walls and some consulting help.
When I decided I was going to build a home for us, I did a lot of research. We looked at earthships (even went to Taos and took the tour), strawbale, and some other design methods. I ended up going with First Day because I knew I could get some help and hire people to do it where I couldn't and I could get a mortgage on it. It's not my perfect dream home, but it's a step up, and it gets me some experience homebuilding of which I have none yet.
I think what I am going to end up doing is building my wooden house first, get experience with the homebuilding process there where I know I can bring in knowledgeable help when I need it. I don't have an expert like you I can bring over to help me. Maybe if we were neighbors!
Once I'm done with my new house, I will be free to experiment beyond prying eyes and inspectors, and use my homebuilding experience on my 20 acre ranch in the mountains. The ranch is 2 hours from where my new house is going to be built (right now I'm about 7-8 hours away in suburbia land in a another state). I think that I will use Mike Oehler's methods to build a small underground house like yours, Glenn. It looks like something I can do. I might want to pick up some earthmoving toys on the way though.
I was talking to the local engineer the other night at the Slow Food dinner. He mentioned that even he had thought of building a minimum house to get past code ----300 sq feet? then doing a few things as he pleases.
You are right about getting things to pass code - rammed earth can be made to pass code with bond beams -etc. but the process changes from free to lots of money as you mention.
You could start honing your skills by building a dog house- barbecue, or out building. of some sort. It does make a fun project.
I'm not really a pro on alot of this stuff -- I just like to read and do and am not afraid of failure - as long as I'm not under it. :-/
That is the key to learning a lot of this stuff - learn what you can then just do it to the best of your ability - usually modifications in future experiments will fix problems you have had in the past. The only ones who never fail are the ones who never do anything.
You heard of "Cast Earth"? I thought this would be something I could have done with a minimal amount of labor costs. Basically they pump a slurry of water, a retarder, plaster of paris, an metal oxides for color with earth into a concrete truck and mix it all up then pour it into forms just like concrete walls. You'd think it was cheaper to do than concrete walls...not!
There's not a lot of labor, just setting up the forms, but considerable equipment costs, like a concrete mixer/pump truck and the forms. A house can be poured in a day or two. It looks a lot like rammed earth but more like manufactured sandstone. Very pretty.
The few folks that have worked with it charge a premium, unfortunately.
:(
If that's what I've seen links to before, it's a patented, expensive training course type of system, so of course it's expensive.
But it's lovely.
Very. I've seen it up close, and man, gorgeous stuff.
Well, not cool tubes.
But here's a description of a dessicant AC unit that is apparently in use in an off-grid house, using a different take on an air-to-air heat exchanger. It requires a very hot attic.
site is associated with a yahoo group.
http://www.fossilfreedom.com/attic.html