concepts · updated 2026-08-01
Sunbender
confidence: high volatility: cold verified: 2026-08-01fresh
The Sunbender® is Zomeworks' reflector and shade panel system for south-facing collectors and skylights. It directs additional winter sun into the building and provides summer shading — a
The Sunbender® is Zomeworks’ reflector and shade panel system for south-facing collectors and skylights. It directs additional winter sun into the building and provides summer shading — a single passive mechanism that improves both heating and cooling. Baer’s 2009 AIA presentation lists “Sunbender® Reflector/Shades” over skylights — “summer shade, winter heat gain” — as a Zomeworks product line dating from 1988; the underlying reflector/shade principle is older, tested by Ron Shore and Baer in February 1974 and visible in the reflector/shade panels of the Baer House photographs.
What it does
In winter, a white or dull-aluminum reflector panel angled below a south-facing collector or skylight reflects additional sunlight into the aperture, increasing solar gain by more than 30% (per Sunspots Ch. 10: Ron Shore and Baer tests, February 1974). The reflected light “gets in free,” since the glass area — and its heat loss — stays the same. In summer, the same panel pivots to shade the collector, blocking direct sun and preventing overheating (AIA 2009: “summer shade, winter heat gain”).
No electricity. No motor. The same refrigerant-canister physics that actuates the Skylid can actuate the Sunbender’s position.
Patent history
The Sunbender developed through four patents:
| Patent | Year | Title | Key advance |
|---|---|---|---|
| US 3,884,414 | 1975 | Solar Heating Device | Skylid louver with interior/exterior refrigerant canisters — the underlying canister physics |
| US 4,275,712 | 1981 | Suntracking Device with Displaced Heating Surfaces | Tracker with heat-collecting plates separate from canisters; morning auto-reset |
| US 4,476,854 | 1984 | Gas Spring Solar Tracker | Gas spring for positive morning reorientation; large + small canister asymmetry |
| US 4,505,255 | 1985 | Summer/Winter Solar Control System | The shade louver system — overlapping louvers pivot between summer (shading) and winter (transparent) positions; solar-actuated by tracker |
Filed on the same day (November 14, 1983), US 4,476,854 and US 4,505,255 together define the complete Sunbender system: the tracker (4,476,854) orients the panel continuously throughout the day, while the louver control (4,505,255) provides seasonal mode switching between winter gain and summer shade.
The patent series continues past the core four: US 4,528,976 (1985, collector overheating protection), US 4,832,001 (1989, the lightweight compression-frame/tension-member support for mounting the tracker assembly), and US 5,143,053 (1992, freeze-tolerant stretchable collector tubes). See Zomeworks patent portfolio.
The Baer House installation
The patent-series ingest notes identify the Sunbender louver shade system with “the mirrored reflector/shade panels visible in Baer House photographs” — the flat panels below the south-facing drum wall glazing. Note a dating tension: the AIA slideshow (2009) lists the Baer Zome / Drum Wall at 1971 but dates the Sunbender® Reflector/Shades product line “1988–”, so the Baer House panels predate the branded product; they embody the same principle rather than the 1980s patented tracker hardware.
From Sunspots (1975), Section 10.9:
Rough tests by Ron Shore and Baer, February 1974: a white or dull aluminum reflector of width equal to the skylight below it increases heat gain by more than 30% during hours the skylight faces the sun. The reflected light “gets in free” since glass area stays the same temperature.
In summer the reflector shades the skylight instead. This is the Sunbender’s fundamental operating principle — the same physical panel serving both roles depending on angle.
Relationship to Skylid
The Skylid and Sunbender share the same refrigerant-canister physics but serve different functions:
| Feature | Skylid | Sunbender |
|---|---|---|
| Location | Below skylight interior | Outside, below collector |
| Function | Controls heat flow through skylight | Controls solar gain and shading of collector |
| Primary mode | Insulating louver (closes at night) | Reflector (winter) / shade (summer) |
| Actuation | Opens/closes on canister temperature comparison | Continuous solar tracking + seasonal mode switch |
The Sunbender is more sophisticated mechanically — it tracks the sun continuously throughout the day, not just sensing inside/outside temperature differential like the Skylid. The gas spring (US 4,476,854) provides the daily reset force.