Cooling a house without air conditioning
Major function of AC is humidity control. If you have humid summers, AC will help your house to stay dryer and prevent mold and other damage. There are climates in which AC is essential and even the most advanced thermal and airflow design can not replace conditioning.
Not everyone has the time and energy to build their entire house, but I found that one relatively easy thing that helps a lot is attic insulation and a bit of DYI. It turns out that contractors often do really shoddy work when it comes to insulation because it's exceptionally easy to skimp on materials to save money: they buy the cheap fiberglass stuff and they use too little of it.
You can buy 15-20 bags of cellulose insulation and rent the blower machine from home depot, and you can do the whole attic in a few hours yourself. Including a rental van, that cost me around $600.
This alone made a noticeable difference in my house in Toronto (where it can easily get to 32°C/90°F in sun in the summer)
This article isn't so much "cooling a house without air conditioning" - it's more "here's some designs for houses that can be cooled without air conditioning".
This has very little to no help for existing homes unless you have a large budget to demo your existing home/yard/surrounding-infrastructure. For a perpetual renter such as myself (bay area lifestyle), this is useless information.
Where I live in the bay area - we live in a greenhouse of an in-law unit. Only solution to cool it without AC would be to tear it down and build something different. I can't even keep the top room below 80F on quite a few days with a window unit I installed. That unit is rated to do over 2x the size of the room too but it can't keep up. On days we know it'll be 95+, we leave the AC on all day. Otherwise, the heat soaks into the walls so much that we can't cool the house down after we get home and it'll still be 85+ in our bedroom past midnight. Opening windows has no effect since we can't get an effective cross-breeze.
I feel bad about it but I don't have much of an option if I want to be somewhat content. I get quite unbearable to be around if I am suffering in the heat.
The funny thing about solar panels is that just having panels above your ceiling cool your house a ton.
It makes me wonder if people in hot climates that can't afford solar shouldn't just put white glossy panels a foot above their roof.
There are a lot of other obvious, non-exotic things we can do, like require a certain amount of tree coverage and reduce the spread of concrete surfaces. We could also use shade sails a ton more than we do (which are nice because they can be removed in the winter).
I was in Phoenix last summer in what (to my poor Canadian body) was the hottest day ever, anywhere. I think it was like 111F / 44C. While my friends and I were over at an outdoor mall looking for dinner, we entered a spot that was more than 10C lower than the ambient temperature. Just instantly colder. I honestly stopped in my tracks.
Above us, a mister was spraying water. None of the water was coming within 10 feet of the ground as it all instantly evaporated- Phoenix is a desert- but in doing so, the air was chilled. The cold air dropped, cooling this small area.
I cannot believe just how effective this means was. Now, granted, to do this they had to waste clean fresh water in the middle of a desert, which isn't great. But it does go to show the potential of some of these tricks. May not work in 99% humidity, mind you, but there are other tricks up the sleeve of the clever engineer.
I only use air conditioning once or twice a year (in DC). This article was very interesting, but if you can't rebuild your home you have fewer options. Here's how I deal with it to make it not miserable.
1. You don't need to cool "a house" - just the room you're in. If I do run the air conditioning for 20 minutes before bed, I'll block under my door to keep that cold air in.
2. If there's no reason for you to be in a hot house, then don't be. If I'm teleworking, I end up not just being cooler, but also happier, if I find a nice quiet spot somewhere else. I'm lucky enough that I have a free museum not far from me that has an indoor courtyard I can work at.
3. Air circulation and window fans that expel heat from the room can do a lot. Fan quality and fan placement is tremendously important for circulation.
4. At least the last two minutes of your shower should be cold.
5. Blinds should be closed during the day.
6. Drink lots of water, of course.
I think there's more I can probably do. For example, I've been meaning to research reflective blinds to see if they do more than normal blinds at keeping out heat. (Shutters aren't an option for my building.) Dehumidifiers are also something I want to look into.
I haven't personally found that bed sheets make much of a difference, outside the way too obvious things like I don't use my winter (flannel) sheets. But this might reflect that I only buy nice ones.
If you live in a dry climate (I'm in Colorado), consider a swamp cooler. It's an amazingly simple and efficient machine: just a water pump and a fan, and peanuts in electrical costs compared to a full air conditioner. As long as you can establish airflow throughout the home, it feels just like A/C on days below 95F; you won't feel chilly on 95F+ days, but it's still quite livable.
The Earthship[1] were designed to solve this problem (among others).
Persians know for millenia how to store ice in scorching desert [1] and have in places like Yazd 'windcatchers' [2]
I've seen through Islamic world and India buildings at least 500 years old that were constructed around constant air flow through buildings, having patterned stone mesh windows. It can be done with low tech approach.
[1] https://en.wikipedia.org/wiki/Yakhch%C4%81l [2] https://en.wikipedia.org/wiki/Windcatcher
Thick stone walls (well brick). I live in Hungary EU, lot of old houses (early XXth/late XIXth century or earlier) has really thick stone walls. In the summer it keeps the house cool (as long as you close the windows and shades) and in the winter it keeps the warm inside. Even if the temp outside is +35c the inside is between 23-25c (or even less)
I have found (in mild but sometimes warm South Africa) that the best bet is to prevent the sun from getting through the windows.
Curtains/blinds are not nearly as effective as external shutters or some kind of external blind.
I make my own frames with light coloured textile stretched across it that I attach over the sun-facing windows, which has a dramatic effect without completely blocking out light.
Yes, a building in San Francisco doesn’t need air conditioning in the summer, what a surprise. Make the same design work in Phoenix Arizona and we’ll have something.
I visited Savannah, GA this summer. In the 19th century houses were designed to have tall ceilings to capture heat, and large doors to verandas to capture wind. It was actually tolerable inside when touring these old houses.
I thought the obvious solution is solar powered run AC. What am I missing?
Why not have solar panels on the roof absorb all the sunlight and keep the house cooler via an air gap?
Furthermore, I would love to have water heating this way. Solar panels heating a water container in the winter, that is mixed into showers and even small pools on demand.
Any observant Jews here who don’t want to use water heating on Shabbat? This may be a great idea.
PS: Heating a house is the only application of Proof of Work Mining that I approve of. But even then, I would rather it be useful work like SETI or protein folding:
http://www.cleantechconcepts.com/2018/06/home-heating-with-c...
There are also air conditioners that don't use refrigerated air. The principles of it are similar to the evaporative cooling mentioned in the article but with a fan and water pump. If your climate is dry enough to use it, it can be a great option and much cheaper than refrigerated air. You'll see one on the roof of almost every home driving through certain neighborhoods of El Paso.
This reminded me of zero electricity air-con made of plastic bottles: https://www.straitstimes.com/world/zero-electricity-air-con-...
The hot air flowing from outside through your windows could be compressed making it cool.
I wonder if there are existing, not so ugly commercial products providing that. This could be a green alternative for air-conditioning.
Granted, I live 'up north' but it still gets hot in my new house. I mounted some exhaust fans in the ceiling to pull the hot air from where it naturally rises too. Combined with the forced air furnace fan to circulate cool air (pulled from floor level). Finds the inside of my house 9C cooler on the hottest days of the year.
This is especially important as the brick gets heat soaked and releases its heat well into the night.
Maybe one of you smart people can solve this "mystery": The old farmhouses here in the region (Flanders) were all built with their length axis on the north-south line, no matter where the road was.
An old farmer here claims that such a house is cold in summer and warm in winter. I once saw an architect on TV claim the same thing. But I was not able to find any explanation for this anywhere.
Ceiling fans are ridiculously effective. I'd seriously consider installing one in the bedroom after the past few years of heatwaves.
This guy grows oranges in Nebraska using very little electricity. He mentions in the video the same principals can be used for cooling.
I live in the southwestern USA, and have no air conditioning. I do have a solid brick house that is an awesome insulator. So we open up all windows and doors at night, and close the house up tight when the sun rises, putting heavy curtains over the windows. It still gets warm - up to 85 degrees inside on a 100+ degree day, but you get used to it.
It wouldn't work on all the suburban homes around us. The walls aren't insulated enough, there are so many windows that you'd never get them all covered.
we've been living in our current house for 11 years. it is a little over a km from the beach in Denmark, it has big doors that open onto the front porch and in a direct line with those doors are the windows in the bathroom, in the summer if we had both open we never experienced the house getting hot. That has actually stopped this year - now we sweat inside. But until this year we had a pretty good way to keep the house cool.
Interesting that this article is posted on the eve of Burning Man. This year should be especially hot. Every year I bring a simple swamp cooler, this year I'm going a step farther and bringing 2, plus an active ventilation fan and ducting. My total power consumption is about 18w, not too shabby to bring down the temps about 15f in ~1000ft^3 space and well within my modest solar panel setup.
The article focuses on strategies effective in arid climates. In California, evaporative coolers worked really well for us except on the hottest days. No way they'd work for us here on the US East Coast.
OTOH, I'm pretty enthusiastic about the exchange systems that circulate fluids to exchange heat with soil beneath home. That's a really reasonable approach.
Funny that this article doesn't talk about keeping warmth out. Whatever you can keep out you don't need to cool. So invest in:
- Insulated glazing
- Sunscreens in front of windows
- Wall and roof isolation
The nice thing about this is that these measures also keep you warm in the winter (lower energy bill), it's a double-edged sword.
UV reflective film on the windows seems to be helping one room in my house which was consistently 10 degrees fahrenheit warmer than the others. Alternately, but a little uglier, taping white kitchen paper towels to the window solved the problem as a temporary solution.
I really wish I could have a well-designed (for electricity use) house. Unfortunately, they don't seem to exist unless you build it yourself, and I can't even dream of doing that (although to be fair I can hardly dream of buying a house at all).
My house has an attic, and an attic fan or vent helps a lot.
I have cheap asphalt roof shingles (even so, $10K to replace them)- I did look into reflective shingles, but they were much more expensive, plus I had to consider resale value..
In Houston? No. Next question.
Whole house fans are one possible solution to reduce (not eliminate) the need for air conditioning - I'm using a quiet cool right now which works fairly well (haven't tried it during the spring or fall yet)
Water, so precious.
https://en.wikipedia.org/wiki/Pot-in-pot_refrigerator rocks.
You can spray water on your roof with a garden hose and cool your house. Of course water isn't free either.
Anyone else browse www.hvac-talk.com from time to time?
The Earthship people called. They want their cool-hunters back.
Solar powered AC
My question: Is it healthy or safe to live in a house or apartment that has no working AC in areas like the southeastern US. I know AC is a modern luxury and that people survived for years without it, but I wonder if the design and construction of later houses or apartments affects anything. My AC ritualistically dies every summer and while I wait for maintenance to drag its feet, I often find myself waking up in pools of sweat
Obligatory reading: The Revenge of the Circulating Fan https://www.lowtechmagazine.com/2014/09/circulating-fans-air...
We used to have these water coolers that worked very well and used very less electricity. You fill up the thing with water and a big fan forces air through husk mats wet with the water. But of course nowadays it is just much easier to simply get an AC installed.
> installing energy-hungry air conditioners – a major contributor to climate change
Is this a fact?
A lot of the need for AC (and having lights on) is just really, really bad modern house design. I recently finished building a house (my first one) and everyone acted like I was crazy for not building in central air conditioning. (This is in New Hampshire)
I built in an older style, with windows on every side, with a mind towards ventilation and light. Inexplicably most houses in the area, even $500k+ houses do not have these two things. My mom's condo has central air but the system is so feeble and the venting upstairs so poor that two bedrooms in the house remain stuffy anyways. It seems like light and natural ventilation are not even afterthoughts, but non-thoughts, and the designs all rely on electric light and forced air. Its amazing being in an expensive home where you need a light on in the kitchen at 8am. How do they decide what to build?
I built 9 foot ceilings on the first floor and 8.5 on the second. Then I placed the attic (3rd story) door centrally in the upstairs hallway. The result of the design is that airflow moves on the first floor in all directions, and upward, and on the second floor can move at least east-west (bathroom and hallway windows), and also north-south if bedroom doors are open. Finally, air flows upwards to the attic, which has windows north-south. So winds should suck air higher, and out.
If I close windows in the morning and open around 7pm, the result is that the house stays very cool, about(? only tested with temp gun a few times) 74 downstairs and 76 upstairs during these 90 degree days, and then gets cooler at night as I open windows again. So far, I've only bought one fan, though things might work better with more. Note I'm not an expert or an architect, I just included some design features that should be obvious to anyone who's lived in an old house for a summer.
This takes some manual control, but there are far fewer parts to maintain (this was a general design goal beyond AC), and summer electric bills are $50-60/month. With this design, there have been 3 icky-hot days so far this year, when there was no wind and the night did not get very cool.