If you are in the market for outward-opening casement windows, you have probably run into the ALPES range and found yourself asking which of the outward-open models is the right one for your project. Three names tend to come up again and again: the C113, the C116 and the C120. All three are thermal-break aluminum casement windows built on 6060-T66 profiles and PA66GF25 insulation strips, yet each has been engineered for a slightly different priority. This article breaks down what makes them different and when each one is the smarter choice.
In short: the C113 Outward-Open Window is a well-balanced, cost-conscious daily option; the C116 Outward-Open Window pushes thermal insulation and unimpeded views the furthest with its wider frame and ultra-slim mullion; and the C120 Outward Opening System Window is the fully-loaded system window that is built to handle the toughest wind pressure and the busiest areas of the home. If you want the strongest structure and the most features, choose the C120. If sleek looks, panoramic light and top insulation matter most, the C116 is hard to beat. If you want dependable performance at the best value, the C113 is your answer.
| Feature | C113 | C116 | C120 |
|---|---|---|---|
| Frame wall width | 113mm | 116mm | 119mm |
| Thermal K-Value | Not stated (multi-chamber) | 1.7 | 1.6 |
| Glass sash thickness | 57mm | 81mm | 62mm |
| Profile thickness | 1.8–2.0mm | 1.8–2.0mm | 1.8–2.0mm |
| Insulation strip | PA66GF25 | PA66GF25 (34–44mm multi-chamber) | PA66GF25 multi-chamber |
| Mullion / frame design | Standard | Slim 22mm mullion | Square cavity, reinforcement |
| Hardware | CMECH | Wehag upgrade available | ROTO transmission & anti-pry locks |
| Best for | Value & all-round | Views & insulation | Strength & heavy use |
The C113 is the entry point of the three and the one most families ｓｅｌｅｃｔ for a standard replacement project. It uses 6060-T66 profiles with an 8mm-thick profile for solid rigidity, and its full glue-injection process with integrated glued corner brackets creates a seamless, single-piece structure that stays stable over the years. The multi-chamber design keeps rooms warm in winter and cooler in summer, while the triple sealing defense blocks wind, rain, noise and extreme temperatures.
A detail worth noting is that the glass centerline, the thermal-break strip and the equal-pressure sealing strip sit on the same axis in the C113, which is exactly the kind of alignment that improves long-term sealing performance. It ships with CMECH hardware, a German Red Dot Design Award winner that has been cycle-tested to 30,000 operations, so the handle and locking mechanisms are built to last. For most homeowners and many budget-conscious builders, the C113 delivers dependable quality without paying for capabilities they will not use.
The C116 takes a visibly different design direction. Its signature feature is the oblique press line with a slim 28mm frame that gives the window a sleek, modern appearance, and the 22mm slim medium mullion keeps the bars out of your sightline to maximize the field of vision. If you are installing windows in a room where natural light and a wide view are the priority, the C116 is the natural fit.
On the thermal side, the C116 uses 34–44mm multi-chamber insulation strips for strong insulation performance with a K-value of 1.7, plus a unified isothermal line design that limits cold bridging. It also includes easy drainage with a flat-channel, obstacle-free system, triple sealing strips with seamless welded corners, and two handle options (a 90° baseless handle or a side-mount handle) so you can match the operating feel to your preference. For those who want the highest grade, an upgrade to German Wehag hardware is available, and the 304 stainless steel high-load hinges with a built-in hardware groove add real durability. This is the model to pick when design and winter comfort matter more than raw structural bulk.
The C120 is the most comprehensive system window of the three and is engineered for the situations where strength and everyday usability are paramount. Its full standard square cavity delivers superior wind pressure and deformation resistance, which makes it an excellent option for upper floors, large openings and areas exposed to strong weather. It is built on a 1.8mm new-national-standard profile with a multi-cavity thermal break system and a K-value of 1.6, the best of the three.
What really sets the C120 apart is its integrated door-and-window-with-mesh design. The nail-free rolled press mesh structure is corrosion- and stain-resistant, roller-precision pressed, and sits flush for a stable, clean fit, so the window doubles as a bug screen without breaking the sightline. The frame, sash and mesh are fully sealed with injection-molded structural adhesive, and high-strength corner reinforcement with complete corner sealing keeps the whole unit stiff. On the security side it pairs a ROTO transmission box with anti-pry lock points and adds an ALPES fall-rope safety mechanism and roller locking device, which is a genuinely useful safety net for homes with children or pets. If you want one window that does everything, structural strength included, the C120 is the flagship.
The right choice depends on your priorities rather than on any single specification. Choose the C113 when you need a solid, proven casement window at the most accessible price and you are not chasing record-breaking insulation numbers. Choose the C116 when visual appearance, slim frames and generous natural light head your list, especially in bedrooms, living rooms or anywhere you want a wide view with strong thermal comfort. Choose the C120 when you value maximum structural rigidity, integrated mosquito mesh and extra safety features for busy or high-traffic areas.
Whichever model you settle on, you are getting a real thermal-break aluminum profile with PA66GF25 insulation and 6060-T66-grade aluminum, all manufactured in line with international building codes. As an aluminum casement window manufacturer and supplier with production centers in Foshan and Zhaoqing, ALPES can customize color finishes, glass configurations and hardware to match your project, whether it is a single home, an apartment block or a large villa development across the Middle East, Australia or Europe.
There is no single "best" casement window model, only the best model for your project. The C113 is the balanced value pick, the C116 shines where light and insulation meet modern design, and the C120 is the strength-and-feature flagship. For a clearer recommendation, share your window sizes, climate and aesthetic preferences, and an ALPES specialist can match you to the right outward-opening casement window in the range. Contact the team for samples, technical drawings and factory-direct pricing.
