conservatory roofs

[coke71]

We're thinking of having 'polycool' (solar reflective inserts) installed into our conservatory roof, the claim is that they keep heat in during the winter and out in the summer without cutting any of the light out. Has anyone had these fitted and if so did they make a difference

[buildersmate]

I can understand the logic of the summer working - the film or whatever keeps out sun's radiated energy.
I cannot see it making a blind bit of difference in the winter - the heat loss in winter is by principally via conduction (not convection or radiation) through the thin and leaky glass or polycarbonate. It's a simple fact that even the best polycarbonate is at least 6x worse than the requirement for Building Regs of a normal insulated roof. Ask Polycool exactly how this is supposed to work in the winter.