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I'm now wondering if painting a roof white is better than covering the same roof with solar panels and using that to drive air conditioning (in the house). My
by rwmj 1y ago
I'm now wondering if painting a roof white is better than covering the same roof with solar panels and using that to drive air conditioning (in the house). My intuition is that painting it white must be vastly more environmentally friendly, although it probably doesn't reduce the temperature very much compared to aircon.
- bragr 1y agoIt's worth factoring in that solar panels also provide solar insulation to the roof by effectively shading it, ie the sun shines on the panels and there is an air gap between the panels and your roof.
- 3eb7988a1663 1y agoIn cooler climates, you are now taking a hit on heating costs. That now blocked Winter sun would have provided some amount of free warmth.
- mauvehaus 1y agoIf it's that cold, you probably have a fair amount of roof insulation anyway that's preventing heat absorbed by your roof from being conducted to the conditioned space.
- 3eb7988a1663 1y agoSure, but the physics still cuts both ways. Either sun hitting the roof causes measurable heating or it does not. The temperature gradient must flow. Sun heating in Winter = awesome. Sun heating in Summer != awesome. I am not arguing the strength of the effect, only that you must account for all seasons.
- Thorrez 1y agoDoes the house already have AC or not? And are you talking about indoor temperature or outdoor temperature? Also many places are cold. Running AC would make it worse.
- thfuran 1y agoThere are certain materials that aren't just white but also specifically radiate heavily in IR bands that the atmosphere is particularly transparent to and so can actually stay sub-ambient temperature while in sunlight. See, for example, https://onlinelibrary.wiley.com/doi/full/10.1002/eom2.12284 https://onlinelibrary.wiley.com/doi/full/10.1002/eom2.12284 But adding conventional AC is never going to cool down the world.
- Projectiboga 1y agoAC doesn't make it cool it merely transfers the heat to the outside in an energy efficient manor. The emerging tech is special coatings that convert heat to an infrared frequency that easily escapes the Earth's atmosphere.
- antonvs 1y agoMost manors aren’t very energy efficient. Take Downton Abbey for example.
- Projectiboga 1y agoThank you! man·ner /ˈmanər/ noun 1. a way in which a thing is done or happens.
- ASalazarMX 1y agoGiven the era it is about, Iy could be considered energy-efficient, as the carbon footprint of individuals and households was much lower a century ago.