Coping with heat

[Creekside]

Is it still hot over there? -6C here this morning. I've switched from keeping heat out to keeping it in. I'll probably remove the tarps over my south-facing windows today to hold off having to fire up my heater.

I heard that eastern Canada had its heat dome collapse.

Yes, all those heat-absorbing surfaces in cities makes a difference. I wonder how much of a difference it would make if the pavement in a city was concrete rather than asphalt.

Someone should do a study of the total economic effects for a city if the council mandated roof colour or types. Even with white granules, asphalt shingles absorb a lot of solar heat. White metal roofs would not be much more expensive to install than asphalt shingles (and the price would drop due to increased demand and supply), and might make a significant savings in cooling costs for all buildings in the city, and make the city air a bit cooler for everyone. I don't think anyone's life would be dramatically worse if they couldn't choose dark red asphalt shingles for their house.

 

[Mij]

And planting trees on top of buildings or just paint the roofs white? I have noticed (living in a high-rise) and looking below that new roofs are being installed in lighter white/grey.

 

[Creekside]

And planting trees on top of buildings or just paint the roofs white?

I'm not sure of the cooling effect of trees. They will absorb more heat than a bright white surface, and raise local humidity levels. Maybe someone has done a comparative study? Trees also trap heat below them. The area under my spruce trees is significantly warmer than the ground around it.

 

[Peter T]

Google AI suggested this 2024 review on the cooling impact of street trees:

Abstract

Urban planners and other stakeholders often view trees as the ultimate panacea for mitigating urban heat stress; however, their cooling efficacy varies globally and is influenced by three primary factors: tree traits, urban morphology, and climate conditions. This study analyzes 182 studies on the cooling effects of urban trees across 17 climates in 110 global cities or regions. Tree implementation reduces peak monthly temperatures to below 26 °C in 83% of the cities. Trees can lower pedestrian-level temperatures by up to 12 °C through large radiation blockage and transpiration. In tropical, temperate, and continental climates, a mixed-use of deciduous and evergreen trees in open urban morphology provides approximately 0.5 °C more cooling than a single species approach. In arid climates, evergreen species predominate and demonstrate more effective cooling within compact urban morphology. Our study offers context-specific greening guidelines for urban planners to harness tree cooling in the face of global warming.

Cooling efficacy of trees across cities is determined by background climate, urban morphology, and tree trait​

See https://www.nature.com/articles/s43247-024-01908-4​

my bolding

 

[Tom Hill]

Heat is one of those things that leaves me struggling more. I have no access to air conditioning.

I thought maybe if there are others who also struggle we could share some tips or ideas that help us.

Last year I bought these window heat reflecting things for the window. I have them in my bedroom. They do reduce the temperature a bit in my room.

https://amzn.eu/d/avhjlAa

Solidarity with you struggling with this. Can you be more specific about how heat affects you? In my case, at its worst, it leads to a feeling of swelling around my sinuses that ends with a terrible migraine in the worst cases. I’ve started trying to prevent heat-related-PEM by regularly rubbing an ice cube all around my forehead and temples until it’s fully melted (though usually for me the big problem is some sort of exercise at the same time as being in hot conditions). And drinking big gulps from a half gallon container of ice water through a straw throughout the day (which seems to cool the blood flowing by, helping reverse the feeling of increases in heat in my head). And plunging my head in a giant cooking pot of cold water regularly (I’m in the Deep South so our summers are long and unbearable even for fully healthy people - and even with AC). But that’s tailored specifically to my own issues with heat. Sharing in case it helps you figure out your own protocol tailored to you.

 

[Tom Hill]

Google AI suggested this 2024 review on the cooling impact of street trees:


my bolding

As someone in the Deep South I can confirm the neighbourhoods covered in enormous Live Oak trees are significantly cooler than the ones without during our epic summer heat. If you roughly calculate the vast surface area of the leaves on a large tree (with each leaf furiously absorbing solar energy for photosynthesis) you start to get a sense of how they can be powerful coolers of the area around.

 

[Sean]

Long time tropical dweller here. Trees definitely work, in two ways: Keeping sunlight off the ground/buildings/you, and cooling the air around them through transpiration.

There is also some interesting work going on developing a new class of reflective paint that are more selective in the wavelengths of light it radiates back out, maximising a certain infra-red range that the atmosphere is transparent to, so the heat it carries get radiated away much more effectively. Apparently they can actually reduce the temperature under the roof to below the ambient air temperature.