Selective Glass – Guardian Sun
Guardian Sun works in both directions: in winter the low-emissivity coating keeps heat in, and in summer the selective layer turns solar energy away before the room overheats. From the outside it still looks like ordinary glass.
Panes · Types Of Glass Panes
Selective Glass – Guardian Sun
available in 39 and 35 (g) variants natural look of classic glass low-emissivity glass — reduces heat loss in winter selective glass — reduces the heat entering the interior in summer in the laminated version blocks over 90% of UV radiation, protecting people and furnishings suits homes, offices and public buildings in practically any insulated unit
The system
large south- or west-facing glazing that overheats by the afternoon rooms where you want the daylight but not the heat — kitchens, garden rooms, sliding systems interiors where flooring, furniture or artwork is fading; the laminated version stops over 90% of UV anywhere the view matters — colours and shapes through the glass stay true, with no tint to look past
Where it earns its keep
The specification
The details worth knowing
The number is the g-value — the share of the sun’s heat the pane lets through, so the lower number is the cooler glass. Selectivity (S) is daylight divided by that heat: the higher it is, the more light you keep for every degree you keep out. Both options reach 0.5 W/m²K in a triple-glazed unit, and both look like ordinary glass.
The brighter of the two. A double silver coating turns solar heat back outside while 71% of the daylight still comes through — the one to pick when the room has to stay light.
Visible light (Lt)
Solar heat let in (g)
Selectivity (S)
U-value
Guardian Sun 39
The cooler of the two. The same coating tuned a step further: 35% of the sun’s heat gets in instead of 39%, for the large glazing that overheats, at the cost of one percent of daylight.
Visible light (Lt)
Solar heat let in (g)
Selectivity (S)
U-value
Guardian Sun 35
Two options
Guardian Sun 39 or Guardian Sun 35
Tell us the room, the window and what the glass has to deal with — noise, a low sun, a ground-floor window — and we will say what we would fit.
Talk to us
Not sure which glass you need?