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> the panels cool water up to 5 ∘C below the ambient air temperature at water flow rates of 0.2 l min−1 m−2, corresponding to an effective heat rejection flux of up to 70 W m−2.

Can someone translate that into layman terms? The chained negative exponents are somewhat confusing. I would think 70 W m^2 would me square meters, but what's 70 W m^-2? I assume it's not really mappable to dimensions at that point...




Sorry, that's the convention of the journal. It's W/m^2 -- heat rejection per unit area.


Oh, I get it now. I totally missed that there wasn't a division there. That makes complete sense now that it was pointed out, I'm just not used to seeing stuff in that format apparently. :)


Negative exponents means its divided by. For instance s^-1 would be equal to 1/s or more formally known as Hertz. You see this every once in a while in scientific papers. This notation is convenient because it makes it easier to simplify the units.


Yeah, it's basic algebra. I just wasn't seeing it for some reason, possibly because I only think about converting exponents like that when trying to solve something (usually when helping my daughter with her Algebra homework). Yet another example of context affecting cognition, I guess.




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