• Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Anne Miller
  • Pearl Sutton
  • r ranson
  • Nicole Alderman
stewards:
  • Joseph Lofthouse
  • paul wheaton
  • Mike Haasl
master gardeners:
  • jordan barton
  • John F Dean
  • Carla Burke
  • Greg Martin
gardeners:
  • Jay Angler
  • Leigh Tate
  • thomas rubino

Natural Air Conditioning

 
Posts: 33
Location: Portugal
5
  • Likes 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

Sorry if this is the wrong forum. Wasn't sure where to put it.

So it's 40C (104F) here the past few days. If often goes up to 48C.
I'm wondering what more I can do to keep my house cool without AC. I have a solar system, it's good but not enough to run AC.

I live in an old stone barn, 2ft thick walls, single storey with a 2-layer terracotta tile roof. Built directly on the bedrock. The sun beats down on the roof all day, so by 4pm I'm suffocating. I spray myself with water and have a standing fan, which is nice, but by 4pm the humidity from all the water I'm spraying, plus me and the dog panting all day adds to the swampiness. The sun doesn't go down until 9pm so there's at least 5 hours of sweltering I have to go through before I can escape outside.
I leave the window and door open all night but it doesn't cool down much. Morning temp outside is 15C, inside it's 25C.

Option 1 is 5cm cork insulation sheets on the ceiling. It's expensive (1200 EU total) but I'm told it's worth it. It will take me until next summer to save up enough.
Option 2 is to knock in another window for ventilation at night. Cheaper by half, but this won't really help me at 4pm though.
Option 3 is to cover the walls outside with clay. But that still leaves the roof to get baked.

Anyone have an opinion on which option will have the most affect?  I'll probably end up doing all 3 eventually, but that will take a couple years so I'd like to know which one would be better to do first.  

I can't start any of these projects until the winter, so in the meantime, if any of you clever folks have any tricks for how to keep the house cooler during the day I'd really appreciate it.  

IMG_20200708_112114.jpg
terracotta brick ceiling and stone wall
terracotta brick ceiling and stone wall
IMG_20200708_112134.jpg
the walls are this thick already, would clay rendering help at all?
the walls are this thick already, would clay rendering help at all?
IMG_20200708_113553.jpg
tile roof. shade netting was considered, but it would have to fight with strong winds
tile roof. shade netting was considered, but it would have to fight with strong winds
 
gardener
Posts: 542
Location: Ontario - Gardening in zone 3b, 4b, or 6b, depending on the day
320
dog foraging trees tiny house books bike bee
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
40 C?! Yuck. I complain if it hits 35. My AC free apartment dwelling aunt in Europe very carefully manages heat like that with windows blinds, windows open on the cool side, and fans to keep cool - but doesn't have an uninsulated roof above.

Roof insulation would be my preference for that situation. Having lived in houses with good and poor roof insulation - it makes a massive difference in the summer. Also shutters or blackout or insulating blinds/curtains for the windows during the day.

I wonder if rolls of that reflective insulation ( brand name here is reflectix) would help? On the ceiling or cut to fit the windows on the sunny side?

Does the insulation have to be natural? Would foam board or fiberglass or rock wool insulation be cheaper than cork? R value is really what you are looking for.

Could you get a ceiling fan? I find them far more effective in keeping me cool than even several floor fans.

Could you whitewash the house and possibly even the roof - white tends to reflect light and therefore be cooler.

For night time ventilation, if you decide to knock in another window, I would suggest making it in a place that allows you cross breeze between it and an existing window.  Do you have a vent near the roofline or a window that can be opened to allow hot air to escape at night, and encourage cooler outside air to be drawn in through the lower levels?  
 
pollinator
Posts: 127
Location: SE Indiana
96
  • Likes 4
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
This stuff webpage
Works great covering our hot hot south patio. If you could manage to attach it to your roof, and extend it out past the roof a ways it might help eliminate a lot of the solar gain during the day.  It's kind of expensive but easy to work with and I've used it several years with no degradation by UV.
Actually the link I gave goes to some that is 70% block, mine is 90%.

We also have outdoor curtains made of it on all south and west windows. And we only open windows when outside temp is equal or lower than inside.
 
gardener
Posts: 3895
Location: latitude 47 N.W. montana zone 6A
1120
cat pig rocket stoves
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi Anna;
I Agree with Catie;   The roof is your weakest link in trying to stay cool.
Adding any insulation there will be the most effective use of your money and time.
An extra window or two would be very nice but with two foot rock walls the labor/cost is not cheap.
Heavy curtains and a ceiling fan, will help as well.
Depending on the cost ,shade cloth would certainly deflect some of that heat.  But not if it blows off every time the wind picks up.
How bad is the humidity?  I suspect it is high.  
If the humidity is not to bad then a swamp cooler (evaporation cooler) could help and they use little power so your solar set up could run it.
You can make your own.
Do you have a good supply of nice cool water? Water dripping on a burlap curtain (or any material) with a fan behind will produce a cool breeze.
Channeling that water away and out to a garden or just a good drainage point is the challenge with a home made evaporation cooler.

I feel your misery. We have a small log cabin with awesome western views... we also can get the high heat that by afternoon can be sweltering.  Thank goodness there is little humidity here!
We do the best we can, by opening all night, using fans to transfer the air. heavy curtains indoors and roll down shade cloth on the west facing windows,  ceiling fans.
Someday's its just too hot and there is not much to do about it. If you can go swimming, if not then light airy clothes and stay in the shade outdoors until it cools enough to stand being indoors.


 
Mark Reed
pollinator
Posts: 127
Location: SE Indiana
96
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator

thomas rubino wrote:Hi Anna;
Depending on the cost ,shade cloth would certainly deflect some of that heat.  But not if it blows off every time the wind picks up.


It is expensive, at least for me. I made a net with about 2' squares of polyester cord, also UV stable and have two layers one above and one below the cloth like a sandwich. The cloth is attached between them with short pieces of cord tying the two nets together. At the edges the two nets are joined and used as the tie downs, all the stress is on the nets, it's handled some pretty strong winds.
 
gardener
Posts: 1828
Location: South of Capricorn
714
dog rabbit urban cooking writing homestead ungarbage
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I've lived in a similar environment now in three houses on concrete pads made of masonry, with and without a concrete structure under the roof. The difference is night and day. Whatever you can do to insulate yourself from the roof will really make a difference, whether that is cork or anything else. Not sure what your winters are like but it will probably also help you keep your heat inside your house when you're cold.
 
master gardener
Posts: 2154
Location: southern Illinois.
530
goat cat dog chicken composting toilet food preservation bee solar wood heat homestead
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Your house is beautiful!  There are a number of good ideas here that I do not want to repeat. So to go in a new direction, have you considered a reflective coating  for the roof?  I am not suggesting to destroy those beautiful tiles, but rather a space blanket like tarp to tie onto the roof....or portions of it.  On a much smaller scale, I have had success using a space blanket as a tent fly when hiking I  the desert.
 
pollinator
Posts: 3656
Location: Kansas Zone 6a
118
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
How is your water supply? Running a sprinkler on the roof does AMAZING things for lowering temperatures, even in higher humidity.  
 
John F Dean
master gardener
Posts: 2154
Location: southern Illinois.
530
goat cat dog chicken composting toilet food preservation bee solar wood heat homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Hi R Scott,

Good point. That takes us to the possibility of a swamp cooler.
 
pollinator
Posts: 1440
Location: Bendigo , Australia
90
dog gear plumbing earthworks bee building homestead
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I studied a few examples of those coppo roofs to understand how they are constructed, but I had trouible getting a clear image of same.
Your roof looks new and may have been constructed with ventilation built into the roof structure. Coppo tiles were used to create an airflow under the tiles.

However, if its possible to get inside the roof and see if battens are exposed, you may be able to fasten reflective sheet under the tiles.
You need a gap of about 2 inches for the material to reflect well.

Then install wool type batts [ earth wool, fibreglass, wool ] insulation on the ceiling as thick as you can afford. I use 300mm depth of the batts.

I live in Bendigo, Australia where 40 C is common in summer.

If there is a cavity in the roof, a powered roof vent will ensure built up heat will be drawn out during the day and at night.
Mine are operated thermetically, in that when the cavity temperature gets to 25C they come on and stop when its below 25C.

The construction of a middle eastern style wind tower  will also help.
 
pollinator
Posts: 3113
Location: Massachusetts, Zone:6/7, AHS:4, Rainfall:48in even Soil:SandyLoam pH6 Flat
322
forest garden solar
  • Likes 2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
You have heat gain during the day from the sun and heat lost during night from the colder air.

I would reduce heat gain during the day by:
1) shading all the walls and windows on the outside with trees/shrubs/curtain/etc
2) painting the roof white, spraying water on the roof, having trees shade the roof esp in the afternoon.
3) removing the hot air at the top of the house with some type of chimney/fan/vent
4) venting the bathroom and kitchen, so that the humid air goes directly outside vs spreading to the entire house. likewise for hot air (oven/stovetop/shower/etc)
6) Increasing the airflow during the night esp at dawn when the air is coldest, can you power a fan from the solar battery
7) Maybe spray the outside wall down at night with cold water so that it can quickly lose all that extra heat.
 
John C Daley
pollinator
Posts: 1440
Location: Bendigo , Australia
90
dog gear plumbing earthworks bee building homestead
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
Perhaps you can give us a few more details of the building.
I have experience that may help.
Some questions;
- Do you have to keep the exterior stone walls as they are?
- Do the walls allow moisture to enter the house?
- Do you have any roof space or a pitched, triangular roof?
- Are you handy with hands?
- Can you shade the walls easily?
- How does the sun hit the house as the day passes/
  - from the side, across the back [low wall] to the other side?
  - Or from the side across the front taller stone wall?
- What temperatures do you get inside of hot days?
- Does it cool down every night?
- How tall are the ceilings?
- Does the ceiling have concrete beams running one way and terracotta beams inserted
 on or into those beams running the otherway?

Stone walls by their very nature bad news.

From Building with stone, problems
"The reason is that with so much uninsulated thermal mass, the house tends to take on whatever the average temperature is outside and just stay there...so in the winter it will be very cold,
and in the summer it might be very hot. The way to overcome this is to add a layer of insulation in the shell somehow.
This can be done in various ways, such as making a double stone wall with an insulated cavity in the middle,
or by putting insulation over the stone (preferably on the outside) and applying a stucco or plaster over this. "

In Australia with a dry heat I use a lot of shade, so if you house was here I would initially shade each wall that faces the sun with shade clothe.
It would be fastened at the top of the wall and be fastened to the ground say 900mm to 1-5M from the wall.
This will allow breezes to pass the wall.
Assuming you cannot attach anything to the roof because of laws, high winds or for cultural reasons, the roof lining I spoke of earlier with insulation over the ceiling.

I would then add a venting system to get hot air out either during the day  and / or at night.
The best systems use electricity and really cause large volumes of air to move. The ones that rely on wind, luck or heat thermals dont usually work at night and do not move a lot of air.

I use a lazer thermometer and measure and record in a diary what is going on, to track improvements with their effect.

I have assumed a few things;
- you cannot paint the roof
- electricity is available
- you can carry out some tasks yourself
- you cannot spray water around, or dont want to.
- you cant wait for trees etc to grow.

 
pollinator
Posts: 352
125
  • Likes 3
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
If you lay a drip hose along the peak of the roof, it should help a lot. I know someone else said to use a sprinkler, but I've had trouble with the water finding gaps that rain misses, because the sprinkler was sending the water in a different direction than normal. But a drip hose should work without causing leaks inside.
 
Posts: 4
1
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
I am no "expert" here but, I have seen and felt the following idea work in real life  I have used it in a desert environment AND it is very simple.  Terra Cotta tubes dripped with water early in the day is passively cooled with air dynamically moving through the tube by convection.  The previous mentioned convection causes air movement and not only is natural but quite satisfying.

Here is a link to one version, anyone can create their own improvements:  https://www.treehugger.com/low-tech-terracotta-tube-air-conditioner-ant-studio-4858405

 
master steward
Posts: 4095
Location: USDA Zone 8a
1239
dog hunting food preservation cooking bee greening the desert
  • Likes 1
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
We have a similar problem, we have a/c though our machine room doesn't have any a/c.  Weather forecast is "excessive heat warnings" with triple digits.

Our problem is all the machines are starting to overheat. If the one for our phone system goes out we will be without any phone service.

I suggested freezing bottles of water, then have a fan blowing over the frozen bottles.  That would help cool the room.  This might be something that might work for you.

Here is how to make a DIY swamp cooler:

https://www.instructables.com/id/Swamp-Cooler-1/




Here are some pictures I found on Pinterest to give you some ideas:









 
Posts: 74
2
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
a couple of good ideas here use of shade sails to shade the roof is always a good idea. Because you are in a stone building one thing that comes to mind.. plant a lot of Vines so the vines will climb the walls an eventually onto the roof.. It creates a wonderful micro climate. make sure you do irrigation so the vines always have enough moisture to expire around the house.  I would also recommend if you can putting up a radiant barrier as mentioned a couple inches from the roof. Best if you have great ventilation at the soffit level The heat will find its way out.  Last couple of things.. put up netting and loose blow in about 2 ft of cellulose insulation(it cheap). Then put up some sort of sheet goods like sheet rock .. get it well sealed around the perimeter of the walls your walls already are pretty tight being 2 ft thick.  Between everything you will be able to let your ac do its job.  Do not know how big your house is.. but where you are likely have high humidity.  Running a dehumidifier may also have a major impact.
gift
 
Rocket Mass Heater Plans: Annex 6" L-shaped Bench by Ernie and Erica
will be released to subscribers in: soon!
reply
    Bookmark Topic Watch Topic
  • New Topic