Dave Smythe

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since Apr 18, 2015
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Recent posts by Dave Smythe

There are videos on Youtube of a setup called Burrow Blocker that fills the holes with a water/sand slurry.


You could also do this on a small scale by the 5 gallon bucketful.
Wonder if ground squirrels make good avocado fertilizer?
1 week ago
One scheme for thermal mass water that I have not seen discussed on Permies is the Skytherm roof designed and built in the 1970s.
Idea is to have a roofpond that is covered/uncovered as appropriate to gain/lose heat depending on season.
Supposedly this maintains the otherwise normal house in the 70s year round in a hot summer/cool winter location in Atascadero CA.
Practically this means having some kind of water container from bottles or gallon milk jugs to larger ones like commercial bladders for liquid foodstuffs in/on your roofspace.
The roof is glazed with a transparent cover such as polycarbonate corrugated panels.
To gain heat in the winter you uncover the water containers during the day and cover at night with insulation to block radiating heat away.
To lose heat during the summer you do the reverse, cover during the day to prevent thermal gain, and uncover at night to allow heat to radiate away.

1 year ago
Just came across this thread now that I am 2 days post-op and minus one gall bladder. I see this is posted under medicinal herbs, but I thought I would post my experience with surgery.
Same day laparoscopic/keyhole surgery went well at Kaiser HMO - 4 small incisions near breastbone, belly button, and two more on the right side of my belly.
I am overweight and live a sedentary lifestyle and while I generally try to eat mostly vegetables I had had several cases of "bad indigestion" over the years, but then a streak of several over a two-week span brought on I think by an ice cream binge on vacation.
Ultrasound showed sludge and maybe stones in the gall bladder and my doctor never really gave me an alternative to removal.
Pain meds are working well and I just feel a bit sore/sensitive here and there. Just cost a $50 copay which is a very pleasant way of getting care.
A previous 2011 lung surgery on a different PPO plan, admittedly a more complex job with 8 days in the hospital was a $200k two-inch thick file of paperwork and I paid for about 1/3 of an inch of it.
Since the ice cream binge I have been eating more carefully and that helps, but I will have to see how things turn out over the long haul.
So far so good.

1 year ago
I wonder if enclosing the tank in glazing would trap even more heat next to the tank?
So a mini tank greenhouse within your main greenhouse. Same principle as double glazing.
1 year ago
All the one-container designs I've seen seem quite cramped although a 40x8 container is really a double or triple-length tiny house.
The best simple design I've seen is two 40 ft containers spaced about 6 or 8 ft apart  (like your 30x40 concept I guess) and offset by about 8 feet lengthways - see the following pin:

Two Container House

This is really open and airy. Note the cutout section of steel from the side of one of the containers could be used for the slanting shed roof.
Another problem with containers is insulation - most people seem to end up building a studwall with insulation inside the container wall which really defeats the purpose.
One cheap option might be to bolt pallets to the outside of the container and then fill them either with insulation and cover with siding, or (my favorite) fill with soil and plant a vertical garden:

If you need more insulation put some sheet insulation between the pallet and the steel container wall.
The container roof can be insulated by putting a layer of straw bales on top and covering the whole with a pitched roof.
Another idea for hot summer - mild winter areas would be a roof pond or swimming pool (!) that would moderate the daily temperature swings.
Temptation is to use the pond to grow tilapia or catfish and filter the pond water through a grow bed on another part of the roof.

1 year ago
I just came across a fascinating photo-essay about the WW2 Anderson bomb shelters Londoners built in their backyards during The Blitz:


Not sure if the J-shaped corrugated iron/steel sections are available anywhere these days but you could build a very livable house out of several of these grouped around a central courtyard, either open to the air or enclosed as a solarium for solar gain.
The covering for the shelter could be dirt or hugelkultur - check out the first photo in the essay of the woman watering her plants!
2 years ago
Well I tried this myself with a pedestal fan, various bottlenecks/constrictions and a couple of different thermometers and I saw no change other than my face is now a bit redder with embarassment.
There's a good video experiment at


that shows there is no measurable cooling effect. The original video at the top of the thread that shows a shot of before and after thermometers is fishy because it shows a difference of 10 deg C which is much larger than the claimed ~5C/10F cooling.
Now if instead they filled the coke bottles with water and stacked enough of them inside their tin shack, they might get some moderation of daily temperature swings, but the daily range between min and max temp in Bangladesh is only about 10 deg C in summer.
2 years ago
I'm surprised how much resistance there is to this. I'm going to try to rustle up a fan, a bottle, and a thermometer and run a test.
2 years ago
Simple test from http://www.geek.com/science/eco-cooler-air-conditioner-cools-a-home-without-using-electricity-1657343/

"To test this, hold your hand up to your mouth then open your mouth wide and breathe out. The air is warm, right? Now do the same thing but with your mouth closed to typical a blowing position. The air leaving your body is cold, right?"
2 years ago
The underlying physics is the Venturi effect which has an amazing number of practical applications according to that wikipedia page.
I wonder if you could use two or three bottlenecks in series, i.e. a stack, to get an even bigger temperature reduction. It would need more wind pressure which you could arrange with a large scoop.
For years we have opened our garage door as a wind scoop to funnel air through a screen door between the garage and our kitchen/dining area. I am going to have to experiment with adding a bottleneck layer to the screen door.
Other ideas are to cut the opening in the bottom of the bottle as a rectangle on the bottle side so as to make the bottle scoop air from wind parallel to the window plane, and by twisting the bottles make it slightly tunable to wind direction.
I have also seen bottles filled with water used in roofs to provide solar lighting - in this case the bottle neck points upward and the bottle body is down below the roof emitting light.
You could make a lighting/cooling window  by combining a rectangular array of intact bottles full of water with necks pointing out with an equal number of chopped bottlenecks pointing in placed so the necks align in the gaps between the full bottles.
You might not even need the outer chopped bottles as the normal ones already provide a constriction in the spaces between them.
At last something useful to do with all the empty two buck chuck bottles

2 years ago