Energy Efficiency Comparison
We break down the technical specs in plain language so you can pick the most energy-efficient window — without needing an engineering degree.
U-Factor
Measures heat loss. Lower is better. Ideal:
Solar Heat Gain (SHGC)
Sunlight turned into heat. Depends on Climate Cool = low, warm = high
Air Infiltration
Drafts through frame seals. Lower is better. Max allowed: 0.30
Solar Heat Gain (SHGC)
Overall energy score combining all metrics. Higher stars = better.
U-Factor Comparison
Lower bar = less heat lost = more efficient
Andersen 100 Series
0.25–0.30
- Good
Infinity by Marvin
0.20–0.24
- Best
ProVia Endure
0.22–0.26
- Excellent
Alpine Windows
0.27–0.32
- Average
- ENERGY STAR® North Zone Threshold: 0.25
Typical performance shown. Actual NFRC ratings vary by configuration and glass package.
Overall Performance Score
Overall energy rating across all metrics
Andersen 100
4.0
Infinity (Marvin)
5.0
ProVia Endure
4.5
Alpine Windows
3.0
Solar Heat Gain (SHGC)
What’s ideal depends on your climate zone
Andersen 100 Series
0.25–0.30
Infinity by Marvin
0.20–0.24
ProVia Endure
0.22–0.26
Alpine Windows
0.27–0.32
- For cold climates (like the Northeast), higher SHGC = more free heat from the sun. For hot climates (like Texas), lower SHGC keeps AC costs down.
Air Infiltration
How much cold or warm air sneaks through the frame
Andersen 100 Series
0.10
- Good
Infinity by Marvin
0.04
- Best
ProVia Endure
0.06
- Excellent
Alpine Windows
0.19
- Average
- Code maximum allowed: 0.30 cfm/sq ft
Side-by-Side Specs Table
All four brands compared across every key efficiency metric
- Full View
U-Factor
Lower = less heat loss
0.27
- Good
0.22
- Best
0.24
- Excellent
0.31
- Average
SHGC
Climate-dependent
0.30
- Balanced
0.27
- Low Gain
0.25
- Best (Hot)
0.32
- Average
Air Infiltration
cfm/sq ft — lower is better
0.10
- Good
0.04
- Best
0.06
- Excellent
0.19
- Average
ENERGY STAR®
Certified rating
Glazing Options
Certified rating
Double / Triple
Triple Only
Double / Triple
Double Only
Thermal Performance Score
Our combined rating
4.0 / 5
5.0 / 5
4.5 / 5
3.0 / 5
- ESTIMATED ANNUAL SAVINGS
$320 – $680 / year
Replacing single-pane windows with top-rated double or triple-pane units. Based on 2,000 sq ft home, mixed climate zone.
Infinity by Marvin
$680
/year saved
ProVia Endure
$590
/year saved
Andersen 100
$430
/year saved
Alpine Windows
$320
/year saved
* Estimates based on DOE methodology. Actual savings vary by installation quality, climate, and existing windows.
ECOVISTA EFFICIENCY PICK
Infinity by Marvin wins on energy efficiency
With the lowest U-factor (0.22), lowest air infiltration (0.04), and ENERGY STAR certification, Infinity by Marvin outperforms competitors — especially in cold-climate zones where heat retention matters most.
