Glazing Materials
Glazing materials are used to maximize
heat gain while minimizing heat loss. Commercial greenhouses use special plastics capable of withstanding UV
degradation, but more durable materials are popular with
home owners who value efficiency, longevity and appearance more than cost.
Methods of mounting, cost, transmittance, reflectance, conductance, durability,
longevity, appearance, and workability are factors to consider when choosing a
glazing material.
|
|
|
Covering
|
Advantages
|
Disadvantages
|
Light
Transmission
|
"U"
Factor
|
Insulating
Value "R"
|
Estimated
Lifetime
|
Cost
per Sq./Ft.**
|
|
Single Polyethylene
Film
|
Inexpensive
Easy to install
|
Short life
|
85 %
|
1.2
|
.83
|
1 year
|
$.06
|
|
Double Polyethylene
Film
|
Inexpensive
Saves on heating costs
Easy to install
|
Short life
|
77%
|
.70
|
1.43
|
1 year
|
$.12
|
|
Corrugated
Polycarbonate
|
High transmittance
High impact resistance
|
Scratches easily
|
91%
|
1.2
|
.83
|
15 plus years
10 year warranty
|
$1.00
|
|
Glass Double Strength
|
High transmittance
High UV resistance
Resists scratching
|
High cost
Difficult installation
Low impact resistance
High maintenance
|
88%
|
1.1
|
.91
|
25 plus years
|
$2.00
|
|
Glass Insulated
|
High transmittance
High UV resistance
Resists scratching
|
Very high cost
Difficult installation
Low impact resistance
|
78%
|
.70
|
1.43
|
25 plus years
|
$5.00
|
|
8mm Twin Wall
Polycarbonate
|
High impact resistance
Saves on heating costs
|
Requires glazing system
to install
Scratches easily
|
82%
|
.62
|
1.61
|
15 plus years
10 year warranty
|
$1.50
|
|
16 mm Double
Wall Polycarbonate
|
High impact resistance
Saves on heating costs
|
Requires glazing system
to install
Scratches easily
|
81%
|
.55
|
1.82
|
15 plus years
10 year warranty
|
$3.10
|
|
16 mm Triple
Wall Polycarbonate
|
High impact resistance
Saves on heating costs
|
Requires glazing system
to install
Scratches easily
|
81%
|
.42
|
2.38
|
15 plus years
10 year warranty
|
$3.10
|
|
HERE ARE A FEW LINKS
TO GET YOU STARTED
http://www.uark.edu/~mrevans/4703/learning_units/unit_03/unit_03_printable.html
http://www.patent-glazing.com/glass%20solar%20control%20intro.htm
http://attra.org/attra-pub/solar-gh.html#glazing
http://www.solar-components.com/default.htm
