Cool Buildings
Table of Contents
Introduction
As the use of cement grows around the world, and seasonal temperatures continue to rise, a growing number of places (particularly cities with heat island effect) absorb the sun's radiation during the day then release that heat back into the atmosphere at night. This can make nights unbearably hot for residents, contributes to the use of A/C systems which actually increase outside temperatures while releasing dangerous emissions (in addition to the emissions created to power these devices). There's also the "wet bulb" issue where humid places are becoming so warm, that even sweating or using water spray for evaporation is no longer effective in cooling people.
Not everyone has the luxury to design or modify the places they live in. A growing number don't even have homes so I've divided the sections below to help pinpoint effective ways to stay cool with regards to building designs or upgrades, traveling in heat, as well as how to keep food from spoiling.
Homes & Buildings
Exterior & Design (General Concepts)
Avoid building materials like concrete or brick if you live in a hot climate, as these are known for their ability to absorb and retain heat. Instead traditional materials like mud have long helped keep communities warm in the winter but cool in the summer. Some places have developed a stigma against more sustainable materials, but they can be used to create affordable, environmental and luxurious homes.
If designing or retrofitting a building with passive cooling systems such as the following which will work day or night without electricity.
Jali or Jaali is the historic use of lattice-like carved stone, but in more recent forms have used plant-based materials such as wood to passively cool buildings in Asia and the Middle East.
Wind towers use a tower, and internal air movement, plus an underground component that wicks moisture from a cool water source.
Use white paint or a similarly reflective colour on roofs, and walls to reflect excess heat, and it is an affordable way to get instant results.
Basements can be a good place for people to escape to during heat waves as the ground around it remains cool and heat naturally rises. These are only appropriate in certain areas. Two big dangers to consider are if your the area experiences severe flooding, and other common basement dangers such as the gas radon.
How This Desert City Stays Cool With An Ancient Air Conditioning SystemÂ
4:17 minute video about ancient passive cooling design.
The Ancient Method Cooling One of Europe’s Hottest Cities
This 7:07 minute video walks through the new twists on ancient designs, including water cooling systems for the solar panels.
Patios & Balconies
Much like gardens, these can provide a little buffer zone to work with and create a cooler microclimate before heat even hits the building or windows.
Accordion blinds, fabric screens, faux or real plant vines, etc. can function as privacy screens, decoration, and passive cooling.
Live plants in pots can help support pollinators, clean your air, and create a cooler microclimate, but they may need additional screening from harsh sun to survive in the first place. A denser planting will have a stronger effect, and planting edible plants can help provide some food even as weather extremes disrupt our access to basic resources.
Note: If you compost on the balcony, make sure to keep it watered and in shade to keep the healthy bacteria thriving.
Roofing
Avoid roof materials that absorb heat like corrugated metal or dark shingles. Instead look to cool roof alternatives which can include terracotta, grass thatch, and surfaces that can be painted white will help reduce internal building temperatures. Note that metal roofs can count as "cool roofs" if they are painted white or other pale shades, as well as other features like proper insulation between the roof and the rest of the building. Metal roofs without these features can quickly turn a home into an unbearable oven!
Green roof or green walls naturally reduce indoor heat (by as much as 30-40°F or "an average of 16.4 degrees Celsius per unit area") while increasing biodiversity and cleaning the air. Many flat or low slope roofs are appropriate for retrofitting or even containers options like flat trays of flowers or veggies fixed to the existing roof, or bringing potted plants onto a tall building to create a patio garden.
Install solar panels which will produce energy while providing shade for the building beneath. There are a growing number of government programs and organizations like Kiva who can help people afford these life-changing upgrades.
Proper attic ventilation helps reduce mold build up while keeping roofs a more stable temperature all year. Click here to learn about more attic-cooling designs, or let me know if there's a better resource I should include!
Extraction fans improve ventilation even further, pulling hot air out and replacing it with cooler air from outside. These fans can be passive, wind powered, electric, and more recent designs are solar-powered.
***Bonus: Intermingling solar and green roofs installations cools the roof enough to make the panels produce electricity more efficiently!
Walls
White or pale paint will reflect the most heat.
Wattle and daub, or well insulated homes will prevent heat from entering the home better than concrete, metal, or brick.
Old, badly insulated buildings can be upgraded with internal insulation, or an insulated façade which can be built directly onto the exterior wall, or custom fabricated for quicker installation.
Green walls can be created with panel systems. They cool the building first by providing increased insulation, but also harness the power of plants to create cooler micro-climates. Green walls can help support wildlife, especially if pollinator-friendly species are chosen. They also reduce air pollution and run off.
Jali or Jaali is the historic use of lattice-like carved stone, but in more recent forms have used plant-based materials such as wood to passively cool buildings in Asia and the Middle East.
External Wall Insulation Installation Guide
4:19 minute video by The Green Age
Windows
Use curtains, blinds, with white or pale backing to reflect heat. There are special layers for making insulated curtains including blackout lining which can reduce energy costs and temperature fluctuations in both the summer and winter. They are a little expensive up-front, but highly effective in making your home more comfortable.
Outside shading including window awnings and trellises help bounce sun radiation away before it even hits the home or comes through the window.
Double or triple pane windows can help insulate again hot summers, cold winters, and even noise pollution from outside.
Window tinting will just reduce the amount of radiation entering the building, but allow enough for daily activities, and allow inhabitants to see outside. Some can be one-way with black, white or even advertising or art on the outside.
Window decals can help reduce the amount of solar energy entering a home. Decals are often smaller and can be decorative. Some designs are more formal or modern. If placed appropriately, these can double as bird deterrents. Allowing birds to see the window instead of having fatal crashes.
Landscaping
Plant trees nearby (most can be put ~3.5 meters from the foundation, but narrow trees can be closer, and wide-growing species should be planted further away to avoid damage to the building or foundation). Evergreens will protect a building year round from sun rain and wind, but deciduous trees will drop their leaves in the cold to allow for the sun's radiation to naturally warm the building. Trees create microclimates which cool communities and held disrupt the heat island effect that is contributing to deaths.
Bushes, hedges, trellises with vines, trees and even shorter plants can help provide shade at various times of day, as well as provide the additional cooling power of evapotranspiration (absorbing CO2 while releasing moisture). According to the EPA "Trees and vegetation lower surface and air temperatures by providing shade and through evapotranspiration. Shaded surfaces, for example, may be 20–45°F (11–25°C) cooler than the peak temperatures of unshaded materials.1 Evapotranspiration, alone or in combination with shading, can help reduce peak summer temperatures by 2–9°F (1–5°C).2,3 "
Pale walls, and light fencing can also provide shade, but may absorb heat. Darker colors will absorb more energy.
If you are unable to grow a vine on a fence or trellis for shade, it may be worth using a screen or even faux leaves to provide extra shade, as this may help shelter live plants long enough to help them gain a foothold and be able to grow without artificial shading. Some gardeners shade their gardens with a trellis or anchor system and cloth for shading the plants.
Traveling Outside
An umbrella or parasol while out in the day can help keep sun radiation from hitting you.
White or other reflective shades, of loose-fitting, natural fiber clothing will keep you cooler than dark, tight polyester or similar blends.
Bike riding is much cooler than traveling in a car, van, tram, or bus with no AC (these can act like ovens and magnify heat). Make sure to take it slow, bring more water than you think you need (think of it as insurance!), wear bright/visible clothes and a helmet. I often don't notice the heat while I'm enjoying the breeze, but peddling can warm you up, so take frequent breaks in some shade, and plan to stop by places with AC or shade along your route.
Public transportation services including buses and trams aren't always properly cooled, but by reducing the number of ICE vehicles on the road, this choice can help reduce overall congestion, air pollution, and heat generated by too many privately-owned engines on the road.
Hand-held fans can help you stay cooler at outdoor events, in sun or shade, and can double as fashion accessories. These are a great touch if you are into costuming or make formal wear feel even more elegant.
Paper Fans
The video shows how to make a paper fan with some disposable knives, and some sticky-backed paper. You could also use used popsicle sticks.
The instructions beneath show the use of glitter, but in recent years glitter has been found to be a major source of microplastic pollution, which is particularly hard to clean from the environment. If you must use glitter, try to find more eco-friendly alternative such as metals based glitters, instead of plastic. Simple paints would probably be better.
Upcycled Fabric Fans
The video below shows how to use scraps of fabric and trim, with a simple dowel (you could cut a broken broom or shovel handle perhaps) to create a simple, but decorative fan.
DIY A/C
These only work if you have access to cool water or ice, and a reliable source of electricity. If you live in a place with unreliable energy, a small solar panel hung in a window could help during daylight. Clay seems to be the most eco-friendly, readily available, and efficient material, but needs a kiln before it can be used. One redditor also suggested using a solar generator to run some fans.
11 DIY Air Conditioners for Staying Cool This Summer There are many other designs and examples, but safety should always be you top concern. Water and electricity make a deadly mix so make sure that no one can trip on any wires, and the device is in a secure location where it can't be tipped or knocked, secure from pets, small children for example. Make sure to do activities involving fumes (like glue or spray) in well ventilated or outdoor areas.
u/jedimastermomma suggested this method for cooling a 2 story home which consists mostly of strategically placed fans and open windows.
British colonizers apparently survived the heat and humidity of India by dipping the bottoms of their curtains in containers of water. The fabric would wick the moisture and help cool via evaporation as breeze from the open windows passed through the fabric. Sunlight helped to eliminate mold, but could instead promote algae growth. So this method would require laundering the curtains from time to time, and line-drying in sunlight helps to sterilize and lightly bleach fabrics.
CoolAnt's Water and Clay Air Conditioner design is based on ancient cooling methods, and doesn't emit any GHGs other than perhaps for the pump. This design could be powered with renewables such as solar to keep the water pump working. If power was unavailable, someone could scoop water from the reservoir over the top of the clay tubes.
Tips for Keeping Cool/Avoiding Heatstroke
Activities
Avoid cooking, especially with methods that release a lot of heat, including ovens, uncovered cooking pots/frying pans, toasters. Cooking outside may be preferable, but raw foods including salads and fresh fruit will help keep you hydrated.
Avoid moving around a lot. Even normal chores may push your body to into heatstroke at higher than normal temperatures.
Stay in the shade as much as possible!
Swimming in cool water, or even sitting with your feet in the tub or a paddling pool can help cool the body.
Sleeping
Sleep on the floor if possible as cool air will be closer to the floor, tile, wood, carpets, vinyl, stone, or dirt will help keep you cooler than a mattress. A yoga mat or similar item may help make the experience more comfortable.
Sleeping with a damp cloth over your body can have a cooling effect.
Community Level Interventions
How America’s Hottest City is Innovating to Survive a 10:51 minute video
This video discusses the benefits for trees, parks, and lawns in hot communities, and how richer neighborhoods tend to have these resources, which immunizes them better against heatwaves than poorer neighborhoods.Â
They also discuss the benefits of cool pavements and community cooling centers.
Cooling Centers
If your community doesn't already have a cooling center, pressuring your local government to open one may help save many lives. Here is a PDF on Use Of Cooling Centers offered by the CDC.
Africa
South Africa
Article explains how retrofitting buildings and converting unused city spaces could help reduce climate change impacts on the local population.
North America
Canada
Victoria: Extreme Heat (PDF) includes map
USA
Texas
During 2023 heatwaves, public libraries shut down and were temporarily used as public cooling centers.
Oceana
Australia
Victoria: Cooler Places includes link so you can ask for local information on cool places.
Organizations & Programs
North America
USA
The Clean Energy States Alliance "is a national, nonprofit coalition of public agencies and organizations working together to advance clean energy.
CESA works with state leaders, federal agencies, industry representatives, and other stakeholders to develop clean energy programs and inclusive renewable energy markets. CESA members—mostly state agencies—include many of the most innovative, successful, and influential public funders of clean energy initiatives in the country."
Oceana
Australia
NSW
Greening Australia: Cooling the Schools Sydney "We are working with students and teachers to add thousands of native trees and plants to schoolyards, creating cooler, greener, more inviting spaces for learning and play. As they plant, students learn firsthand about the environmental and cultural benefits of planting native trees for First Nations cultures, urban cooling and biodiversity."
NSW Government: Urban Greening Program "To create a sustainable, liveable and cool Greater Sydney, we need urban greening, which includes urban canopy and green cover. More urban greening means communities have more shade, cleaner air and more beautiful places to live.
The Greening our City Program has several initiatives to help reduce urban heat and create a cooler, sustainable and more liveable city.
The program aims to increase green cover across Greater Sydney and contribute to lifting urban canopy coverage to 40% by 2036."
Grants & Funding
Asia
Livable Cities: Financing Partnership Facility "The urban operations of ADB benefits from the support of notable trust funds, which are collectively referred to as the Urban Financing Partnership Facility. Under this umbrella, strategic, long-term, multi-partner investments on innovative urban solutions are implemented. These investments help to achieve the vision of livable cities." These include:
Urban Climate Change Resilience Trust Fund (UCCRTF) eligible countries include Bangladesh, India, Indonesia, Myanmar, Nepal, Pakistan, Philippines, and Vietnam.
North America
USA
Power Forward Communities "is a coalition of some of the country’s most trusted housing, climate, and community investment groups dedicated to decarbonizing and transforming American housing. We’re saving homeowners and renters money, reinvesting in communities, and tackling the climate crisis."
Oceana
Australia
NSW
NSW Government: Grant Programs "Urban greening grant programs support local councils across Greater Sydney to enhance urban tree canopy and green cover in our local parks, streets and neighbourhoods. More trees mean more shade, cooler suburbs and attractive places to live and work for our communities.
Each project contributes to our objective of achieving 40% urban tree canopy cover across Greater Sydney by 2036.
Since 2019, the grant program has funded the delivery of 131 tree planting and demonstrations projects across four grant rounds. These projects will result in over 107,000 new trees planted in areas where they are most needed, creating greener, shadier and more attractive suburbs across Sydney."