[wessorh]

Seems like a lot of work. Greenhouses sometime need shade so we coat them in 50lb bags of Hydrated lime (Calcium Hydroxide) which can be purchases for really cheap. While I enjoyed the video when I have thousands of squarefeet that need coverage hydrated lime works great.

[retrocryptid]

Hydrated lime doesn't cool the reflecting surface below ambient.

[01100011]

But it turns into CaCO3 after absorbing CO2 from the air, no?

[elmolino89]

The input substrate to produce CaO is CaCO3. This requires a lot of energy, often obtained by burning coal and the reaction releases CO2. Absorbing CaO/Ca(OH)2 makes sense only in systems like submarines/bunkers with no external air supply. As a CO2 capture method on a large scale is makes no sense. Even if we think about using CaO as some "CO2 capture and release" material with who knows, storing pure CO2 underground, I think even theoretical no CO2 emitting energy needed for baking CaCO3 has a better use.

[01100011]

What? Did you respond to the wrong comment? Can you tell me what you think my comment is trying to say?

[OlympusMonds]

Yeah, but making lime is very energy intensive.

[mrob]

If the lifetime energy savings are greater than this energy cost then it's still a good idea. You only need a thin coating so it sounds plausible to me.

[retrocryptid]

Did you read the paper?

[littlestymaar]

Wrong thread? (because there's no paper being discussed in this one…)

[retrocryptid]

Scroll up. Find the reference to the paper. Click on it. Read it.

[littlestymaar]

Bad bot

[rabf]

A well applied lime wash is something more people should be aware of in the modern world. If you live in an old stone building it is what you should be using for exterior stonework and not modern paints!

[_jplc]

Tested and proven during centuries https://en.wikipedia.org/wiki/White_Towns_of_Andalusia

[elmolino89]

It is not the problem with lime vs another white paint outside of the buildings. Modern paints based often containing TiO2 are more durable.

But I am with you that using lime especially on roofs/sun exposed walls (assuming lime does not eat up some materials) before summer is sensible if done correctly. Otherwise we will have a spike in hospital admissions of ppl splashing lime over themselves.

[rabf]

Modern paints are often not breathable causing moisture to get trapped in the walls causing no end of problems to historic buildings.

[elmolino89]

Good point. Indeed such impermeable to even water vapor paints peal off/cause the damage to bricks/stones under.

[soligern]

Seems like a lot of work to do yourself but if made commercially there’s nothing in the process that would make the end product very inexpensive either.

[fullspectrumdev]

You say that, but in chemical engineering stuff like this is always a LOT harder to scale than you would think :(