Glazing Materials

Glazing Materials Class

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.

C = COST/sq. ft.           measures the cost of the glazing per sq. ft.
T = TRANSMITTANCE    measures the visible light that passes through the glazing.
R = REFLECTANCE        measures the IR radiation trapped by the glazing
U = CONDUCTANCE      measures the heat loss through the glazing
D = DURABILITY           measures the resistance to breaking due (High, Low, Moderate)
L = LONGEVITY            measures the expected life span of a product in years.
A = APPEARANCE         measures the aesthetic appeal (High, Low, Moderate)
W = WORKABILITY       measures how easy the material is to work with (H,L,M)

The following table compares some popular glazing materials. Your first task will be to finish filling this comparison table by using research tools available on the internet and any other resources you wish. After sufficient data is gathered and compiled we will summarize the data and verify it with some hands on research. FRP = Fiberglass Reinforced Plastic

GLAZING MATERIAL C T R U D L A W

Glass single pane	$4	.9
Glass double pane	$10	.8
Lexan .5"	$5	.7
Plexi glass .25"	$3	.9
Polyethylene single	$.04	.8
Polyethylene double	$.08	.7
FRP untreated	$2	.7
FRP treated	$3	.8

or you could get a little more involved with a table like this:

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 to 4 years	$.06
Double Polyethylene Film	Inexpensive Saves on heating costs Easy to install	Short life	77%	.70	1.43	1 to 4 years	$.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

We'll use the bulletin board and chat room to divide up the work load and communicate our findings. What we learn will be as important as how we learn. Cooperation is an important part of this online classroom learning experience.

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.biogeorecon.com/tutorial.htm

http://www.solar-components.com/default.htm

Chat Room Bulletin Board

Good Luck. I'll stop in from time to time to see how you're doing.