Sliding Windows — Comet, Zeus and Ultramax
We build three sliding window ranges. This page gives their tested numbers — including one rating we're deliberately not publishing until our sources agree, because a wind rating you can't stand behind is worse than none.
What they are and where we use them
Sliders run horizontally and suit wide openings — and like double hungs, nothing projects when open, which suits paths and walkways. Comet is the residential default, Ultramax the step up in tested performance, and Zeus the companion to our Zeus double hung where a home mixes both.
Wind ratings and tested performance
Our Comet sliding window tested to N3 — both single glazed, and double glazed in the non-exposed position for general and corner windows. Worth knowing: the double-glazed test recorded no rating at all in the exposed position, so we don't claim one there. Our Ultramax sliding window tested to N4 with 1000 Pa serviceability, 2000 Pa ultimate and 300 Pa water resistance.
For our Zeus sliding window we hold conflicting figures across our sources — three documents, three different ratings, possibly different specimens — and we're not prepared to quote a rating until that's resolved with the manufacturer. Quoting the highest figure would be exactly the wrong thing to do. Zeus energy figures are certified and published below; only the wind rating is withheld.
Does double glazing change a slider's rating?
The wind rating comes from the frame, sash and hardware rather than the glass, but each configuration is tested as its own assembly — our Comet slider illustrates it: single glazed N3, double glazed N3 non-exposed but no exposed rating recorded. We always check the rating for the exact configuration being supplied.
Energy performance and glazing options
All three ranges have double-glazed configurations. Sliding window sashes take 4, 5 or 6mm single glazing and an 18mm double glazed unit — thinner than the 24mm our awnings take, which is part of why sliders certify slightly behind awnings on U-value: around 3.2 for a Comet slider double glazed against 3.0 for the Comet awning. Zeus slider certifies 3.3 to 4.3 double glazed.
Sizes and configurations
Zeus and Ultramax sliding windows run up to 2100mm high by 3000mm wide overall depending on configuration. Comet sliders also take the 135-degree bay coupler for bay arrangements.
What we'd recommend them for
Wide openings on reasonably standard sites: Comet. Exposed positions needing N4: Ultramax, whose 1000 Pa serviceability gives real margin. If your schedule specifies a Zeus slider on a wind-rated item, talk to us first — we'll match the item to a system whose rating we can certify today.