PVC — IGLO Series
IGLO LIGHT
The slim-mullion 5-chamber window. 32% narrower movable mullion than the standard IGLO 5 system. More daylight per opening, less visible frame. Uw = 0.88 W/(m²K). For projects where the ratio of glass to frame is part of the design intent.
- 0.88 W/(m²K) Uw
- 32% slimmer Movable mullion
- 5 Chambers
- 70 mm Build depth
- Warm-edge Swisspacer (free)
- Ug 1.1 Double-pane glazing
Why spec this one
IGLO LIGHT is built around one specification: the movable mullion is 32% narrower than the standard IGLO 5 system.
The movable mullion is the vertical frame element between two operating sashes in a double-sash window. On a typical PVC tilt-turn it is wide because it carries the locking hardware and steel reinforcement for both sashes — usually the widest visible element of the window. IGLO LIGHT redesigns that mullion with different reinforcement geometry and hardware layout, giving a significantly slimmer visible frame at the meeting stile.
Three downstream effects:
- More daylight. Same opening size, more glass area visible. Brighter interior, particularly on north and east elevations.
- Cleaner view through. The thin mullion stops drawing the eye to the frame — the window reads as glass with a thin trim.
- Modern aesthetic. The slim profile matches contemporary architecture without going to aluminum.
If the project specifies daylight performance, sightline minimization, or contemporary residential aesthetics on a PVC budget, this is the model.
Standard equipment
- MACO MULTI-MATIC KS hardware with 2 anti-burglary engagement points and Silber-Look anti-corrosion coating
- Sash lifter (sash position blocker, dependent on window height)
- Microventilation on tilt-turn sashes
- Hinge covers in 4 colors (white, silver, light brown, brown)
- DUBLIN aluminum window handle
- Double-pane argon-filled IGU at Ug = 1.1 W/(m²K)
- Swisspacer Ultimate warm-edge spacer (free option)
- V-Perfect weld corner
- 2 EPDM perimeter seals in black
- 1.5 mm U-channel steel frame and sash reinforcement (2 mm for balcony door)
- White PVC core
- 5-chamber PVC sub-sill profile with seal
Performance specs
| Thermal transmittance (Uw) | 0.88 W/(m²K) |
|---|---|
| Frame chambers | 5 |
| Build depth | 70 mm |
| Movable mullion width | 32% narrower than standard 5-chamber systems |
| EPDM seals | 2 (interior and exterior perimeter) |
| Glazing (standard) | Double-pane single-chamber, Ug = 1.1 W/(m²K), argon-filled |
| Spacer | Galvanized steel or Swisspacer Ultimate warm-edge upgrade (free option) |
| Acoustic insulation | 34 dB |
| Anti-pry engagement points | 2 with MACO MULTI-MATIC KS |
| Steel reinforcement | 1.5 mm U-channel in frame and sash (2 mm in balcony door sash) |
Full technical detail
IGLO LIGHT is a 5-chamber PVC tilt-turn window system at 70 mm build depth, designed for daylight maximization through a redesigned movable mullion that is 32% narrower than the standard IGLO 5 system at the same depth and chamber count, manufactured from primary PVC with embedded steel reinforcement.
The movable mullion — the vertical frame element between two side-by-side operating sashes — is the most visually prominent element in a multi-sash configuration on standard PVC platforms. On IGLO LIGHT it is engineered with revised internal geometry that allows the same hardware platform and structural performance at significantly reduced visible width, giving a higher glass-to-frame ratio, increased daylight transmission, and a sightline closer to modern aluminum systems.
Thermal performance of Uw = 0.88 W/(m²K) is achieved with the standard double-pane argon IGU at Ug = 1.1 W/(m²K) and the Swisspacer Ultimate warm-edge spacer included as a free upgrade (a differentiator from the standard IGLO 5 program). Upgrading to the triple-pane double-chamber IGU at Ug = 0.5 W/(m²K) reduces the Uw to approximately 0.71 W/(m²K).
Hardware is MACO MULTI-MATIC KS with Silber-Look anti-corrosion coating, 2 anti-burglary engagement points, sash lifter, and microventilation; the DUBLIN aluminum handle is standard. Steel reinforcement is 1.5 mm U-channel (2 mm in balcony door sash); the mullion uses a custom reinforcement geometry delivering standard structural performance at reduced visible width. EPDM sealing uses two perimeter seals in black; V-Perfect corner welding provides clean weld seams.
Acoustic insulation is rated at 34 dB with standard glazing; heavier acoustic packages are constrained by the slim mullion glazing thickness limit. For ratings above 40 dB, the IGLO ENERGY 7-chamber line is recommended. Operation types include tilt-turn, fixed, tilt-only, side-hung, and top-hung, with the slim mullion advantage most visible in two-sash and three-sash groupings. Application range is residential new build and replacement, multi-family, and light commercial across the Northeast. NFRC-equivalent thermal data and mullion comparison drawings available by direct request.
Colour range
Pick a foil finish — the preview updates live.
Selected finish:
Where it fits
Spec it for
- Contemporary residential where daylight maximization is on the program
- North and east elevations where the slim mullion compensates for limited natural light
- Replacement work where existing windows have heavy frames and the client wants more visible glass
- Multi-sash window walls and horizontal banding installations
- Premium residential where PVC is acceptable but the aesthetic needs to read modern
Don't spec it for
- Single-sash standard openings (use IGLO 5)
- High-performance residential requiring Uw < 0.8 (use IGLO EDGE)
- Acoustic-driven projects above 40 dB (use IGLO ENERGY family)
- Outward-opening applications (use IGLO EXT or IGLO PREMIER)
Within the line
IGLO LIGHT, EXT, and PREMIER all sit on the 5-chamber 70 mm platform with different signature features.
| Model | Uw / Ud | Chambers | Depth | Notes |
|---|---|---|---|---|
| IGLO 5 | 0.89 | 5 | 70 mm | Standard 5-chamber |
| IGLO 5 CLASSIC | 0.83 | 5 | 70 mm | Three colors, wider Renolit |
| IGLO LIGHT This model | 0.88 | 5 | 70 mm | 32% narrower movable mullion |
| IGLO EXT | 0.89 | 5 | 70 mm | Outward-opening, concealed hardware |
| IGLO PREMIER | 0.89 | 5 | 70 mm | Outward / top-hung, scissor hinges |
Lead time and process
Quote in 5 business days. Lead times typically run 8 to 12 weeks from order confirmation.
Inspirations
IGLO LIGHT windows in real homes across the Northeast.
Ready to Price an IGLO LIGHT Package?
Send drawings or a window schedule. Note which openings include multi-sash configurations where the slim mullion is the design intent. We respond in 1 business day.
90 Dayton Ave, Suite 212, Passaic, NJ | Serving NJ, NY, PA, CT