Natural Cooling

For anyone that has built or owned a natural building. Is there a way to cool a natural building without electricity? I live in the midwest where it gets fairly hot around uppers 80s on average.

If you have a low north-facing opening and a high south-facing opening (by which I mean window), open both and allow air to travel freely through your house from one to the other.

Block out the midday sun as much as possible.

If you have ceiling fans upstairs set them to push air upward and turn them on.

Plant deciduous trees in front of south-facing windows. In the summer they'll have leaves and shade the windows, but in the winter the bare branches won't block too much sun.

Just a few ideas, there are probably many others...

Install insulation inside the roof.  This slows the heating of your attic space….assuming you have an attic space. I am not talking about insulation above the ceiling between the joists but under the roof between the rafters.

Invest in a solar vent fan for the attic.

A higher price approach is to take a practice from experienced tent campers. Install a fly.  Installing a metal roof above your present roof with air space to allow for natural venting will significantly lower internal temps.  Of course, it will help I’d the “fly” is reflective.

If the high is 88F and the low at night is 68F, you will find that if you set a sensor inside the house it will stay at 78F for most if not all the 24hrs.
The issues is that you are constantly adding heat to your building so lets identify the heat sources and how we can mitigate those heats.

Solar Radiation.
"Paint the roof white"
Add a liner and then add 1inch of sand to the roof, then have water drip circulate to cool your roof
Create a GreenWall by planting vines along the walls or even just some shade trees, or have huse roof overhangs

Kitchen
Bake less and use your stove top more
Vent your kitchen of all the moisture and heat
Use an outdoor kitchen

Bathroom
Take colder shower
Vent your bathroom of all the hot vapors and moisture
Use an outdoor shower/bathroom

Laundry
Vent properly
Use an outdoor one
Dry on a clothline

Electronics
If you are using 30KWHr of electricity per day, then that means that you are adding 30KWHr of heat into your space.
Use less electricity, and lower powered ones, etc

Thermal Buffer
If you add more thermal mass to your house it will help

Insulation
If you add more insulation, then your AC will not have to work as hard

Humidity Control
Maybe there is a way to absorb the humidity from the air, then during the next day "boil off" the absorb moisture and then re-use it.

Ned Harr wrote:Plant deciduous trees in front of south-facing windows. In the summer they'll have leaves and shade the windows, but in the winter the bare branches won't block too much sun.

I, and others, have planted pole beans to run from a planter up to the eaves. Shade, food, and they only last for the hot season!

If you have dry air, look at the historic architecture of the Arabic countries. (Iran, Morocco, Algeria, Saudi Arabia...)

- Avoiding sun hitting the walls
- thick walls
- Good ventilation

For existing building:
-insulate the roof
-add shading plants; on the southern side I would only recommend annuals - in winter you don't want to shade your southern wall
-casement windows that fully open for ventilation
-avoid cooking inside

For new building there are numerous approaches, but for that climate I would do masonry walls, prope eaves, insulation, high ceilings, good placement of casement windows.

In the Middle east tall wind
towers are built on homes to pull air through the building. Air is usually drawn from a courtyard with
fountains so moisturised air is pulled through aND upwards.
I started a topic on it but cannot find it at the moment a while ago.

Look at this information

Also look at this topic
https://permies.com/t/220447/Wind-towers#1933580

This is an awesome topic!

I remember from several years ago seeing house designs that were designed with passive solar cooling in mind.  The houses all had good southern exposure which helped to heat the homes during the winter months (assumes northern hemisphere).  The sunlight from those southern facing windows would shine upon huge masonry cylinders that were filled with water.  The masonry was heat conductive and the water has an amazing specific heat capacity meaning that the cylinders could hold a lot of heat for release over night.

In the summer months, things reversed.  The sun was no longer low in the sky and passed right overhead.  This meant that the southern windows were properly shaded by an overhang specifically designed for the exact latitude.  The masonry cylinders were located adjacent to a set of skylights that were kept shaded in the summer daytime by louvers.  At night, the louvers were opened.  Any heat absorbed by the cylinders was then radiated out the top of the roof through the skylights, cooling the cylinders and cooling the house.  During the daytime, that giant, cool mass then absorbed heat from the inside of the house as the house warmed up during the day.  The result was a considerably cooler interior than would otherwise be the case without that great big cooling mass.

This effect can be amplified with some clever painting.  There is a special, highly reflective white paint made from barium sulfate (which is harmless and used medically as an X-ray contrast agent for diagnose GI problems.  It is simply consumed orally as a thick liquid).  Barium sulfate has the unusual property of being even more reflective that fresh snow!  When painted on a surface and exposed to direct sunlight on a bright sunny day, the painted surface actually cools instead of warming!  The barium sulfite reflects almost 100% of the radiant energy and it further radiates away heat to the open sky, thus cooling the surface!  This does not work quite as well during days where there is a thin, overcast layer of clouds that lets in sunlight but blocks heat radiation.  But still, this works wonderfully during hot, cloudless days and in amazing during clear nights!  Perhaps the combination of a barium sulfate painted roof and cooling masses inside could really work together to cool down a house on an otherwise very hot day?

I thought this was worth some thought.

Eric

I'm at Zion National Park, where the temps have been in the 70s and 80s. The visitor center is naturally cool with this design.

The stick built house I’m in the hot desert was designed for somewhere else. It gets hot during the day and cold at night. It needs help. I’m tired from going in and out ten times a day struggling with the broken evaporative cooler that isn’t working correctly. I can’t get anything done because this thing and the heat takes most of my energy. And it’s using a lot of water. I’d like to plant vines but the they have to be protected from all the hungry animals that would devour them. That means fences and other protections from the wind which will whip up and destroy things. Everything feels like a big project because the house was not designed well from the outset. I think they were snowbirds who never intended to live here in Summer. And did not plan on much gardening.
 My current bandaid fix is to funnel the water from the leaking evaporative cooler to a few trees so the water is not wasted. And to run the cooler at night. That’s what I should have done last night but didn’t. I loath bandaid fixes. I’d prefer to fix this house permanently so it doesn’t need much cooling.  But for now I’m looking at sail shades on the west and east side which are great but need huge posts or the wind will take them to the next county. And vines that cover areas that the sail shades dont cover but it’s too late for vines this season. So much is about timing.. This is the goal for next spring. Build planters in winter and plant in spring. And fix the old evaporative cooler. If it was my house I’d do a rammed earth addition to add mass and much more insulation in the roof. I’d build a tower on the roof to suck warm air out and draw cool air in from tubes buried under the rammed earth addition. I’m frustrated after studying this stuff for 30 years to end up with another poorly designed stick and drywall house. Built for somewhere but I dont know where lolz. I see broken down houses out here. As if someone just gave up. I fear I might end up like that. Starting over is hard. Sigh.

Jeremy Baker wrote: If it was my house I’d do a rammed earth addition to add mass and much more insulation in the roof. I’d build a tower on the roof to suck warm air out and draw cool air in from tubes buried under the rammed earth addition.  

I'm strongly in favour of local building codes that prevent exactly the frustration you're feeling from the Permaculture saying, "wrong plant in the wrong place" only the housing version! Have you considered a version of a water wall out of upcycled buckets? Ideally stacks near windows?

My engineering son says to stop summer heat from entering, you need to hang "curtains" on the outside - like from the eves. Can you get cheap sheets/curtains from Charity shops in your area? Can you attach them under the eves in a removable way and make each section small enough that they'll flap like flags in the wind, but not actually cause damage or be damaged?

Hang in there - it's frustrating to know what needs to be fixed, but not have the resources or power to just get on with it. Definitely I would work on planters as time allows, as projects so often take longer than we think. In my ecosystem, some shrubs trees actually do better when fall planted than even spring. The experts all say plant in November. The garden shops always sell fruit trees in the spring. Sigh...

I just want to put one small note in. People talk about vines or other shading devices on the south side, but i also recommend the west side. This is because early morning sun is often welcome even in summer, but the afternoon sun, in the hottest part of the day, needs to be screened out. We built out house up against tall trees to the west for this reason--it works even better because there is a steep hillside there, covered with trees busy with transpiration--so cool air comes in with the prevailing breeze, through the downstairs and upstairs windows on the west side, then goes out through the cupola.
Another thing is we have off-grid solar. We have to conserve energy in cloud, short-day winter, but this time of year we don't--so when it's hot, it's surely sunny and it's no problem to run fans--even big ones but we mostly use little homemade ones my husband made out of two computer fans soldered together, which need only a few watts.

Just thought to share a comment and ideas about the picture with the screen hook. The red cart you see is made of metal frame with canvas cloth. I found a bin that fit inside it perfectly which then holds two 5 gallon pails which I use to carry grey water from kitchen sink out to yard. I used to hand carry the buckets one by one but that got so hard to do! So thankful for this option and idea that came together. Found this cart at the second hand store. I lined the cart with cardboard to keep clean- it lifts out easy and protects the canvas somewhat. The bin is to help catch the water that sloshes out of the buckets as I'm pulling the cart over rough terrain, even with lids on. Found that too at the thrift store just the right size (no lid so it was cheap)! I then just lift out the bin and pour the spilled water on the plants after the buckets are emptied. I use a small container to dip out the water from the full buckets when I don't feel like lifting them out full. The container stores in a corner of the bin as there's space also for small tools like trowel or clippers too if I need them where I'm going.  So handy and a back/arm saver that helps in re-using water too!

Here is a video about ancient cooling using a method of air pathing through subsurface rooms, and then out at a higher warmer area. The temperature difference will make the draft.

Similar theories about hearing and cooling discussed in the ebook "the earth sheltered solar greenhouse"
This link is selling the book, but there are many free resources out there.  
https://permies.com/t/141701/Chapters-Earth-Sheltered-Solar-Greenhouse

Here is a video where Mike discussed some of his underground building
https://paulwheaton.com/oehlers-earth-sheltered-solar-greenhouse/

Without knowing details about your building site, I would suggest that both wind and water are important resources that need to be funneled for effective cooling. Being near water is often a cooling thing.

For the best water use of your land, I would suggest the method known as key line irrigation. This was designed by a man by the name of P.A. Yeomans.

https://www.scribd.com/document/80339307/p-a-Yeomans-The-Keyline-Plan

The basic of keyline irrigation is to utilize contour and elevation to your benefit. They do this deep plowing along contour lines that nearly irrigates itself, as it is said to be much more efficient use of natural rainwater than the normal topography. They also discuss the importance of gathering rainwater up high, to allow for controlled distribution downhill in times of drought.

I mention keyline irrigation, because they discuss how to route water safely so that it doesn't degrade your roads. The tactics here are said to reduce the surface area of the land dramatically.  Cooler area around you would lend to cooler breeze.  You want the opposite of standing on hot asphalt.

Two easy ways of having cooler ground is planting cover crops, and mulching to where the sun does not beat onto soil.  There are many tactics in permaculture that could help towards cooling.  

It would be really fun to brainstorm some solutions for you.

A largely underground house with a well-insulated roof goes a long way on keeping warmer in winter and cooler in summer. I can't stand rooms without windows though, so no wall is completely underground, and the south and east are mostly above ground and mostly glass for the view and winter heating. Outdoor curtains made of light-colored polyester bedsheets or shower curtains found at yard sales keep the summer heat out very effectively. They are on all widows except north. Polyester seems to be very UV tolerant and lasts a long time. They block the heat but still let in a lot of light.  A strip of duct tape is folded over at the top edge and stapled because the tape won't stick to the polyester, more tape is used to fix the taped edge to the window frame, easy to apply and remove and works great. Shade trees strategically placed at the SE and SW corners such that their branches don't block solar gain in winter help too. The entire west end is shrouded by trees. The north is wrapped in evergreens to reduce winter winds.

A significant issue with keeping a house naturally cooler than outside is some 95-degree very humid air still gets in, moisture condenses, and everything is damp. I've found no solution to that other than running a small air conditioner. 5000 btu seems sufficient for the whole house but since it doesn't have to do much in the way of cooling it has to run at full throttle, or it switches off and often still does. At night once we are in and the door won't be opened again, we can turn it off. So much water drips out the back of it through the day, we use it to water patio plants.

S Bengi wrote:

Thermal Buffer
If you add more thermal mass to your house it will help

Insulation
If you add more insulation, then your AC will not have to work as hard

This video was just posted this morning.  It's kinda long.  But, in it he shows a fascinating method for moderating the temperature swings in his shed.  It would take some time and expense to set up.  But, it looks like it might be able to moderate building temperatures for years with no further energy input.



On his channel he has experimented with some other interesting heat reflective materials.

This company is into this business
https://pcpaustralia.com.au/

Ryan Burkitt wrote:For anyone that has built or owned a natural building. Is there a way to cool a natural building without electricity?

I have built a natural building. To summarize the many prior posts, yes, there are multiple ways to cool a natural building without electricity.

Some excellent methods discussed include using the thermal inertia of the earth.  First, earth tubes: buried ventilation pipes that draw into the structure air cooled and dehumidified by ambient subterranean temperatures.  Second, building an earth-integrated structure, such as an underground building or an earth-berm building, to tap into those ambient temperatures through direct contact rather than convection.

A less extreme but still effective version of the same concept is to build a non-earth-integrated building with enormous mass in the walls, so that they possess their own thermal inertia.  Examples would include a monolithic cob structure, or possibly earth bag or adobe brick structures if the walls are exceptionally thick.

The problem is that all these techniques could potentially work for new construction, but if you are talking about an existing, conventional, above-ground structure - the OP didn't specify - then they are out of the question.  None can be retrofit.

Actually, it might be possible to add earth tubes after the fact, but it wouldn't be easy, and I don't immediately see how it would work without incorporating electric fans.

My own experience is with a non-earth-integrated natural building: a fairly conventional, above-ground structure integrating some natural/alternative materials into a passive-solar design.  You will find a subtle bias in the literature to discuss passive-solar architecture in terms of heating a building.  But it can be just as effective at cooling a building.

In a very brief nutshell, passive-solar architecture works like this: design your structure around a large thermal mass exposed to the interior space; wrap around that mass a building envelope as highly insulated as is practical to construct; orient the whole structure according to (or very close to) the cardinal directions; and then carefully position and size the windows, doors, and roof overhangs so to control the ingress of direct sunlight into the building.  There can be additional subtleties to it - optimizing indirect daylighting, accounting for local conditions like prevailing winds, incorporating exterior plantings and landscaping, choosing appropriate types of window glass - but I've just summarize the core principals in one paragraph.  And depending on one's design choices, it is possible to achieve good passive-solar results without adding $1 to your design.  Except for the cost of "extra" insulation and roof overhangs, but the general architectural advantages of these features should be self-evident to a smart designer in any case.

During the winter, your interior thermal mass is flooded with direct sunlight and naturally warmed, in turn warming your rooms and occupants.  During the summer, it is kept (nearly) completely shaded and absorbs no additional heat except for ambient room temperature.  In the evening, as soon as the temperature outside drops below the temperature inside, you open up windows to let the cooler air in.  This can be improved using exhaust fans, but they are not necessary (since we are aiming for "without electricity").  A good design includes high and low windows - possibly including a clerestory or a steeple - to create a passive thermosyphon that draws in cooler air all night.  In the morning the windows are closed again, and the thermal mass retains the cooler nighttime temperature into the day, in turn cooling rooms and occupants.  An unused rocket mass heater can be well integrated into this summertime system.

According to the books, a thoroughly designed passive-solar building has 1/3 less need for climate control.  Will this keep you cool in the Sahara?  By itself, it would keep you cooler, but probably not cool enough.  It would be a good start, but there are other traditional architectural techniques designed for cooling in a desert climate.  I find it is very adequate (together with minimal electricity invested in ceiling fans) in South Carolina.

But can you retrofit any passive-solar benefits into an existing structure?  Not easily, but it could be done.

To start, you need interior thermal mass.  This could be achieved by adding a trombe wall in a good spot, if you can make the room for it and if the existing floor can support the weight.  This is a massive interior wall, often a half-height wall, typically made of compressed earth or masonry +/- 1 foot thick.  Water is also an excellent thermal mass.  Adding an interior pool would work, but is probably impractical for anything but the most extreme retrofit.  A "trombe wall" made by permanently lining up very large water vessels is a possibility.  If your structure is built atop a monolithic concrete slab foundation, this will be the easiest way to gain your thermal mass, because it is already there.  Tear up any carpet and foam and subfloor - think of these as insulation separating your thermal mass from the interior space - then refinish the slab by staining and sealing it as a finished floor, or by covering it directly with non-insulating material like ceramic tile.  And remember what I said above about a rocket mass heater.

Now that you have some mass, you need to control its exposure to direct sunlight.  This is why passive-solar design orients the building North/South/East/West, because then it is very easy to choose on which walls to locate and how to size your windows and doors.  The goal is to have minimal openings facing East and West, or none at all, where it is impossible to control sun exposure during sunrise and sunset; modest openings to the North, which are essentially holes in your insulated building envelope, but also can provide desirable indirect lighting (and sometimes code-mandated emergency egress); and large openings to the South, to let direct winter light flood your interior mass.  Your roof overhangs and possibly additional plantings will keep summer light out.  Note that South-facing windows can be too large, also.  There is a science to optimizing these openings relative to your thermal mass and climate, which I won't go into here.

Existing conventional construction would have been oriented to face the street, which means for our purposes that the building orientation will be totally random, and no thought will have been put into location or size of windows and doors.  Do your best to add exterior awnings and/or perhaps plantings to come as close as possible to the ideals outlined above.  If you can't do that, interior blackout curtains would be the next best thing for some windows, if you can live with them.  Because any of these solutions will be jerry-rigged onto a less-than-ideal building plan, it may be necessary to manually raise, lower, open, close, install, or remove some of these throughout the day or the year in order serve our passive-solar goals without completely shutting out light or views.

Finally, you are ready to consider ventilation.  If you don't have high-level windows or vents to open to create a thermosyphon, or you can't install some, you must rely on cross ventilation from ground-level windows and screen doors.  With double-hung windows, this can sometimes be less effective than the books would have you believe.  Casement windows are better.  If you find that natural cross ventilation isn't sufficient at night, you might have to bite the bullet and burn a little electricity to run some fans.  Adding a whole-house exhaust fan is still a cost-effective investment compared to air conditioning.

Apres la pluie, le beau temps
After rain, nice weather - whatever that is
And indeed, there has been a huge volume of rain, epic flooding not far from me, and now it’s hot and sunny. Grass is very tall, needs attention even if I am a bit of a jungle bunny.

Inside, the thick stone walls are keeping very cool.

The RMH acts as a cooling tower, sucking up hotter air.

On a thread somewhere I read that it could lower the temperature by 2 to 3 degrees.
I imagine that any stove with a tall chimney, when left open, can act as a cooling chimney.

I have used wet sheets in open windows as a cooling medium when in very hot climates.
The shade and dampness were effective in improving level of comfort.

I appreciate all the suggestions, the longer term plantings and the more immediate hanging of curtains or blinds or whatever outside the living space.

At the recycling place where I contribute, work for the love of it, we wil be be having a meet up to think about the pros and cons of heat. How to stay well and how to use it.
It’s not all negative. Cooking outside was mentioned  here, so we might have another tulip solar oven workshop.
Super easy and quick to assemble. We found a local printer who kindly let us have his waste from offset printing, thin shiny metal sheets, lots of aluminum? lightweight, easy to store.
It’s not the most efficient system of cooking but it is a very encouraging start.

And let’s not forget warm, even hot drinks to get our own sweaty cooling system going.
I’ll keep reading, testing and learning, thank you with blessings

M-H