WINDOW FILMS FOR ENERGY CONTROL
Value in Weatherization Programs
– Darrell Smith, International Window Film Association–
Introduction to Window Films of Today • Primarily a solar control retrofit product
• From dark or highly reflective products to clear films • Scratch resistant coating standard
• UV protection standard
• Some safety benefit from all film use
• Some of newest films being introduced in low-e versions • Over 200 products now NFRC-certified
Why Consider Window Film in Weatherization Program • Proven to be one of the most cost effective and energy
efficient retrofit technologies available
• Generally has lower climate change impact than many other solutions, especially replacement options • Even where little short-term advantage, can have huge
advantage in savings per investment basis in longer term • Changes being made in N.E.A.T. program to evaluate films
Analysis Comparing Film Retrofit to Window Replacement • Used RESFEN software for analysis
• Home model
•1500 square feet., single story, existing window frame •Envelope package Exist01 (AL1), R11 Ceiling, R7 Wall,
R0 Floors
•Slab on Grade Foundation, no basement •Electric heat pump for both heating and cooling
Analysis (continued)
• Window options
• Existing home: single pane clear glass, aluminum frame/no thermal break
SHGC=0.86, U=1.10
• Upgrade with Film: same existing window with neutral gray film applied
SHGC=0.49, U=1.10
• Upgrade to New Low-e Windows: SHGC=0.42, U=0.42
Initial Savings Review Annual
Annual savings Low-e Electricity savings with low-e Film Window
cost with film window Installed Installed Location per kwhr upgrade upgrade Cost Cost Film only on East, South, West Exposures w/ Low-e windows on all exposures
Miami FL $ 0.080 $110.08 $143.60 $720 $4,440 Tampa FL $ 0.100 $105.80 $161.40 $720 $4,440 Phoenix AZ $ 0.100 $116.50 $227.40 $720 $4,440 New Orleans LA $ 0.080 $54.40 $112.56 $720 $4,440 Houston TX $ 0.100 $74.00 $157.20 $720 $4,440 Bakersfield CA $ 0.140 $71.40 $207.62 $720 $4,440 Dallas/Ft.Worth TX $ 0.100 $49.30 $161.10 $720 $4,440 Birmingham AL $ 0.080 $20.80 $105.44 $720 $4,440 Atlanta GA $ 0.080 $17.44 $102.56 $720 $4,440 Little Rock AR $ 0.080 $17.44 $122.80 $720 $4,440 Los Angeles CA $ 0.140 $2.52 $61.04 $720 $4,440 Sacramento CA $ 0.140 $19.74 $165.48 $720 $4,440 Kansas City MO$ 0.100 ($10.30) $198.20 $720 $4,440 Baltimore MD$ 0.100 ($24.50) $159.50 $720 $4,440
Lifespan Savings
20-year Low-e 15-year Low-e Film Window Film Window Installed Installed Lifespan Lifespan Location Cost Cost Savings Savings
Film only on East, South, West w/ Low-e windows all exposures
Miami FL $720 $4,440 $1,651 $2,872 Tampa FL $720 $4,440 $1,587 $3,228 Phoenix AZ $720 $4,440 $1,748 $4,548 New Orleans LA $720 $4,440 $816 $2,251 Houston TX $720 $4,440 $1,110 $3,144 Bakersfield CA $720 $4,440 $1,071 $4,152 Dallas/Ft.Worth TX $720 $4,440 $740 $3,222 Birmingham AL $720 $4,440 $312 $2,109 Atlanta GA $720 $4,440 $262 $2,051 Little Rock AR $720 $4,440 $262 $2,456 Los Angeles CA $720 $4,440 $38 $1,221 Sacramento CA $720 $4,440 $296 $3,310 Kansas City MO $720 $4,440 ($155) $3,964
Savings to Investment Ratios Low-e 20-year Film Window Ratio 15-year Low-e Savings Savings Film SIR
Film Window to to to
Lifespan Lifespan Investment Investment Low-e Window Location Savings Savings Ratio Ratio SIR Film only on East, South, West Exposures w/ Low-e windows on all exposures
Miami FL $1,651 $2,872 2.29 0.65 3.55 Tampa FL $1,587 $3,228 2.20 0.73 3.03 Phoenix AZ $1,748 $4,548 2.43 1.02 2.37 New Orleans LA $816 $2,251 1.13 0.51 2.24 Houston TX $1,110 $3,144 1.54 0.71 2.18 Bakersfield CA $1,071 $4,152 1.49 0.94 1.59 Dallas/Ft.Worth TX $740 $3,222 1.03 0.73 1.42 Birmingham AL $312 $2,109 0.43 0.47 0.91 Atlanta GA $262 $2,051 0.36 0.46 0.79 Little Rock AR $262 $2,456 0.36 0.55 0.66 Los Angeles CA $38 $1,221 0.05 0.27 0.19 Sacramento CA $296 $3,310 0.41 0.75 0.55 Kansas City MO ($155) $3,964 (0.21) 0.89 -0.24 Baltimore MD ($368) $3,190 (0.51) 0.72 -0.71 $9,369 $41,718 0.93 0.67 1.38 Summary of Analysis
• Only thru lifespan analysis can full comparisons be made • Many films have better SHGC and have larger savings • Some of the newest films in low-e version have larger
savings
• Most films have lifetime residential warranties, so if lifespan of base window longer, total savings on film use more • UV protection from film healthier for occupants and saves
General Concerns About Film Use 1. How do I know which type is best? 2. What does it cost?
3. Will it make my windows too dark or shiny? 4. How long will it last?
5. How can I find a dealer in my area?
6. How do I know the dealer is telling me the truth? 7. Where can I go for more information?
Answers to Concerns (1)
• The only real measure of total solar film performance on a given window is the Solar Heat Gain Coefficient (SHGC)
• Can be found by subtracting the Total Solar Energy Rejected (TSER) from 1.00
• Is approximately .87 times the Shading Coefficient (SC) • Infrared Rejection (IR) not a measure of total energy
performance
Answers to Concerns (2)
• Film costs depend on area of country, type of film selected, and type of window/glass on which it is to be installed • General price ranges (installed) would be:
• Standard films: $3.00-$5.00 per square foot • Hybrid films: $4.00-$7.00 per square foot
Answers to Concerns (3)
• Window films of today do not need to be dark or shiny to have high heat rejection
• Conventional films had to either increase amount of tint (absorb more heat) or amount of metal (reflect more heat and light) to improve
• Newer films use metals which reflect more infrared energy and reflect visible light less and in color
• Some of the newest films also have low-e properties
Answers to Concerns (4)
• All quality window films today have manufacturer’s warranties
• Most are limited lifetime on residential
• Warranties include removal of old film and reinstallation of replacement in case of failure
• Contact information for manufacturer is on warranty in case dealer does not comply
• Warranty is a manufacturer’s printed document and not from the dealer or distributor
Answers to Concerns (5) • Consumers can find dealers
• Using the Yellow Pages under “Glass Coating and Tinting” • Going to the IWFA website (www.iwfa.com) and using the
Find A Dealer program
• Going to the IWFA website (www.iwfa.com) and using the Locate a Distributor or Locate a Manufacturer and then asking for a recommendation
Answers to Concerns (6)
• The consumer should ask the dealer for copies of the following BEFORE signing a contract for film installation
• Copy of the manufacturer’s Film-to-Glass recommendations showing the selected product is recommended for his/her window
• Copy of the manufacturer’s warranty he/she will receive
• Copy of any glass breakage/seal failure coverage from the manufacturer included
• A sample (8” X 10”) of the film to be installed with a
Answers to Concerns (7)
• If you or a consumer needs more information, they can contact the IWFA office at:
International Window Film Association P.O. Box 3871
Martinsville, VA 24115 Phone: (276)666-4932 Fax: (276)666-4933 E-mail: [email protected]