'ENTS
3 ECONOMICS OF SHUTTERS AND
SHADES 25
Dollar Value of Heat Lost Through Windows 26
Dollar Value of Heat Saved by Shutters 26
Maximum Acceptable Cash Outlay for Shutters 27
Some Graphs of Heat Saving 28
Incremental Cost vs. Incremental Saving 31
List of Miscellaneous Penalties and Benefits
Associated with Shutters 31
Does the Availability of Free Heat Affect
the Economics? 32
4 CONSIDERATIONS GOVERNING DESIGN
OF SHUTfERS AND SHADES 34
Brief List of Criteria of Success 35
How Great a Reduction in Heat-Loss
Should One Seek? 35
Use of Trapped Air 36
Seals 36
Optical Properties 38
Convenience 39
Durability 39
Warping 39
Moisture 40
Danger of Overheating the Shutter or Glazing
on Hot Summer Day 41
Sudden Temperature-Change Danger to Thennopane 41
Fire Hazard 41
Other Hazards 41
Chimney Effect 42
Wind 42
Reducing the Wind Speed 42
Principles Relating to Manufacture, Shipping,
Installing, and Adjusting 42
Which Location is Best: Outdoors Between
Glazing Sheets, or Indoors 43
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