Re: Which is the best material for an aerial sleeve?
I guess that would be down to the vertical pipe getting less overall exposure to the UV as the sun direction moves round than a horizontal one which would have one side exposed all day. When the sun's high in the sky, the energy/area exposed for vertical would be less, too.
Whether this would just slow down the degradation or there's a "threshold below which" effect, I've no idea.
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