how long are their expected service life on the poles before they need to be replaced?Do they last just as long as porcelain insulators?
all insulators have to be periodically cleaned, inspected and maintainedpolymer or plastic have failure modes that glass or ceramic do notFirst being a plastic, they will eventually deform in response to applied stressSecond, the complex chemical compound is broken down through exposure to ultraviolet sun radiationThird, being not as brittle, they suffer more from wind/dust erosionThey are more apt to breakdown if exposed to corrosives in the airAnd finally they are sensitive to thermal factors and can melt in the event of current overloads/lightning in the conductors 10 years would be a generous average, it could be shorter depending on environmental conditionsglass/ceramics are proven performers with a good safety record that will be hard for a new product to match.
The most important part of the window is the glassA number of options are available, Argon filled, Lo E, tempered, etcSome of these options have to do with insulation factors and others like Lo E prevent the suns rays from changing fabric and carpet colorsVinyl windows are the standard for new home constructionThe extra cost of fiberglass is not warrantedYou can get complete information at Lowes, Home DepotThey also sell and install windows.
