Passive Home Cooling

Discussions center on passive strategies for keeping houses cool without air conditioning, such as thermal mass, insulation, nighttime ventilation, shading, and reflective surfaces, especially in hot climates like deserts or the southwestern US.

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e.g US SP UrbanForestry DC PS PV AC youtube.com UK cooling heat house roof ac insulated thermal insulation temperature solar

Sample Comments

makomk Apr 2, 2021 View on HN

Keeping heat out is of somewhat limited use unless you have air conditioning, because there are a whole bunch of sources of heat (people, appliances, solar gain through the windows, etc) that are enough to make the inside of a well-insulated and well-sealed building warmer than the outside. Also, a lot of non-US countries strongly discourage aircon on residential buildings for environmental reasons; I know the UK certainly does and Canada is probably similar.

gdpgreg Apr 6, 2019 View on HN

The feasibility of this is completely determined by the insulation and albedo of the house. Working around the thermal inertia of the house is tricky, blasting the AC hard at night is only effective if your house is moderately well insulated or good at not absorbing heat (reflective roof, wall insulation, reflective blinds etc, and by reflective I don't mean tinfoil, I mean like white or bright colored, basically no black or dark). Building elements are remarkably bad at storing heat/c

ClumsyPilot Jul 5, 2023 View on HN

Might be huge thermal mass?It does need heating in winter like any normal house, but does not het hot in summer days

guard-of-terra Aug 21, 2014 View on HN

When there's a lot of sun your home needs cooling, when it's cold there is not much sun.

ndjskska Jul 28, 2019 View on HN

Have some decent insulation and sun blinds. Keep windows shut during the day and open at night.Works in many hot places around the world. AC can be complementary, but you dramatize.

FreshStart Jul 6, 2023 View on HN

Which is just bad construction? You can add coolant reservoirs to buildings. The tiles in Mediterranen housing come to mind. You could make temperature creep highways, like moving the water of a night cool pool into the cellar. It's just rarely done because moving part and lots of space. Finally AC, a gets your air cold, thus the materials in contact with air, but it's way to late a defense line. Sunlight does not have to reach your house. Plant trees or have masts with sunsails on th

kevinmchugh Jan 8, 2019 View on HN

Do those have enough thermal mass to make a difference?

OldTimeCoffee Jun 16, 2021 View on HN

What the article describes won't work in most houses as it's designed around a thermal chimney. It doesn't work with high temperatures, even at only 85 degrees it's 78 inside. They note that building is effectively unusable during heat waves and the hottest part of the day. And the article ends by noting that the problems are continuing to get worse as the temperatures increase.AC cooling has massive advantages, there are solid reasons why every building should have heat p

codingdave Aug 23, 2019 View on HN

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 ge

fizgig Sep 29, 2016 View on HN

Not having active cooling in the arid southwest US does not necessarily mean dangerously hot during the day. When night-time temps can hit the 50s and 40s in higher elevations, a house with decent mass can remain comfortably cool throughout the day if you ventilate properly at night.