How to Read Roller Shade Fabric Optical Data: Ts, Rs, As, Tv and g-tot

Keep four kinds of information apart

For a consistent solar-energy accounting basis, Ts + Rs + As should total about 100%; rounding can affect the displayed sum. Tv is a separate visible-light quantity and does not belong in that sum. An openness value should not replace either quantity.

Use the openness and sample-selection guide for the broader room and privacy decision. The task here is narrower: checking exactly what a particular data row measures.

Read one real row, then check its limits

Phifer’s SheerWeave 5000 swatch card, version v24-072624, lists the following for color P60 Bamboo/Birch. This is an attributed manufacturer example, not a Saiwenna supply offer or a substitute material.

1. Check identity. Keep the collection and color together. Another color in the same collection can have different values.
2. Check the accounting. 21 + 59 + 20 = 100. This confirms the arithmetic of these displayed solar columns, not the accuracy or applicability of a laboratory result.
3. Keep visible light separate. Tv is 18 in this row; it is neither the sum above nor a direct promise of room comfort.
4. Read both glazing headings. The same fabric has two reported g-tot values under two stated glazing conditions. Taking 0.24 into a different window schedule without checking the glass would remove an essential condition.
5. Retain installation assumptions. The card identifies internal installation and zero-degree profile angle. Compare the project condition with the original report or manufacturer data before using a value in analysis.

Compare like with like

Build the comparison from exact codes rather than descriptions such as “white 3% screen.” Record the face presented toward the glass where the source distinguishes face and back, and keep the measurement basis or reference report. If two sheets use different glass or conditions, mark their combined-performance columns as not directly comparable.

When a source provides only a summary number, request its underlying basis for the selected material. A low visible-transmission figure may inform glare assessment, but the room’s viewing direction, bright sources, glazing and controls still matter. Avoid rewriting a fabric percentage as a guaranteed reduction in discomfort or energy use.

Likewise, daytime outward view does not prove privacy with indoor lights on after dark. Assess the actual sample under the relevant lighting. A blackout fabric also leaves the finished assembly’s edge gaps, channels and interfaces to be reviewed separately.

A worksheet for the material decision

Material identity

Manufacturer ______ Collection ______ Color/code ______ Face/back ______

Source identity

Document/revision ______ Page or table ______ Test/report basis ______

Fabric properties

Openness ______ Ts ______ Rs ______ As ______ Tv/VLT ______

Combined performance

Glass type ______ Installation ______ Profile angle ______ g-tot/SHGC ______

Project objective

Glare / outward view / privacy / heat / other ______ Priority ______

Sample observation

Location and lighting ______ Viewing directions ______ Result ______

Unresolved comparison

Missing or inconsistent fields ______ Confirmation owner ______

Carry the accepted fabric into the shade specification

The optical decision is one part of a complete shade configuration. Preserve the approved code and document version alongside fabric width, orientation and seams. Review those manufacturing questions with the railroading and seam guide, and keep material thickness and roll build-up in the physical section review.

Then match the fabric and shade dimensions with the tube, drive and mounting configuration in the roller technical pack. Saiwenna’s currently published catalog category or color code alone does not establish tested optical properties, current stock or a confirmed sample scope.

Prepare a fabric sample review Include the exact source row, project objective and unresolved comparison so the next discussion addresses a defined decision.