Window Systems

LECTURE SEVEN

Window Systems

Blinds shutters, shades, and drapery

If a drapery covers more than 10% of the wall it is often considered an interior finish by many codes.Specification of design components for window covering systems should be evaluated on the following criteria:

The site – trees, ground surfaces, orientation to sun pathExterior appendages – Shutters, sun screens architectural features, etc.The window framing components – type of operation, sizeWindow glazing methods – applied films, reflecting glassThe building interior components.

Window Systems

Drapery fenestration Data

When sun hits the window treatment the glass and fabric act to:

Transmit a portion of light and heatReflect heat back to the outsideAbsorb heat from the light

Window Systems

Determining the fabric fenestration values

Visible propertiesOpenness factor - % of light transmittedVisible transmittance – used for comparing glare and opacity

Solar Optical PropertiesSolar transmittanceSolar reflectionSolar absorption

Window Systems

Determining the fabric fenestration values, con’t

Shading CoefficientThe lower the shading coefficient the greater the efficiency of the systemMore efficient systems - .40 to .60The fabric color has an effect on this factor

U- valueThe amount of heat conducted through the window configuration -

The lower the U- value the greater the efficiency of the window system.

A U-value of .65 is possible for a single glazed window.A U-value of .37 is possible with two layers draperies.

Window Systems

Determining the fabric fenestration values, con’t

Air tightnessThe volume of air passing through an openingThe closeness of the drapery or window treatment is important.

Additional Considerations Dealing with Energy ConservationDrapery should stack clear of the glass openingConditioned air should not blow between Window Txand the glassThermal liners may be used for better reflection.

Window Systems

Window Systems

Determining Window Measurement and Hardware

Issues you will need to consider:The type of Window TreatmentOperational directionAvailable lengthsDrapery headings accommodatedApplicationBracket supportsMaximum fabric weight accommodated

Window Systems

Determining Window Measurement and Hardware

Critical Measurement Dimensions For Hardware

Formula for Determining the horizontal placement to clear window when fully opened:

Add 12” to the total width of the windowExample – 100 + 12 = 112”

Divide the total by 6112 6 = 18 2/3” – round to the next number, 19

Extend bracket 19” on each side of the window – this will clear the window when open.

Window Systems

Determining Window Measurement and Hardware

Drapery Estimation

Calculate amount of textile needed – Without pattern

1 Finished length – The distance from the top of the rod to the bottom of the drapery – usual 1” clearance at the floor

2 Cut Length – Distance (#1) plus hems and top headingsMay add 18” for sheer material, 17” for unlined, 13” for linedEx. - 84” (finished length) + 17 = 101” cut length

3 Finished width – Distance from bracket to bracket plus the return. Add an additional 6” for center overlap.120” (length of rod) + 3” +3” + 6” = 132”

Window Systems

Determining Window Measurement and HardwareDrapery Estimation, con’t

Calculate amount of textile needed – Without pattern, con’t

4. Number of widths requiredFull Width (FW)

100% fullness is 2 times the width150% fullness is 2.5 times the width200% fullness is 3 times the width.

Finished width x 2.5 Width of fabric supplied = number of widthsIf fraction then increase to next whole numberDivide by two if two panels for draperyExample:

132” x 2.5 = 330” fabric (48”) = 6.87 (7 panels) 2 = 3.5 panels for each half.

Window Systems

Determining Window Measurement and Hardware

Drapery Estimation, con’t

Calculate amount of textile needed – Without pattern, con’t

5 Number of yards required – multiply number of panels required by the cut length to determine the total number of inches required.

Divide by 36 to get total number of yardsExample:

7 panels x 101” = 707” 36” = 19.63” or 20 yd

Window Systems

Determining Window Measurement and Hardware

Drapery Estimation, con’t

Calculate amount of textile needed – Textile With pattern

If pattern then more material would be needed to accommodate the matching requirements. Example:

If cut length was 101” as above example and the Pattern repeat was 24” it would require 5 pattern repeats.

[4 x 24 = 96” so would need extra pattern to include 101” (5 x 24 = 120”)].

120” X 7 Panels = 840”One extra repeat is suggested, so:

840 + 24” = 864” 36” (inches per yard) = 24 yds.

(For institutional Curtains (as around a hospital bed)Measure track length and add 10% for fullness to determine width. The other

calculations would remain the same.

Window Systems

Determining Window Measurement and Hardware

Drapery Fabrication

Pinch pleat SystemsStack pleat systems

7-1/2” spacing – stacking, 3-3/4” deep8-1/2” spacing – stacking, 4-1/2” deep10” spacing - stacking, 5” deep

Roll pleat systemsAccordion – type pleating systems

Window Systems

(Reznikoff, 1989)

Window Systems

Window Systems

Window Systems

Determining Window Measurement and Hardware

Shades and Blinds

Horizontal blinds

Window Systems

Determining Window Measurement and Hardware

Shades and Blinds

Vertical

Window Systems

(Ballast, 2002)