What is a window rating?
Energy Performance Ratings The rate of heat loss from a building is indicated in terms of the U-factor (U-value). U-Factor ratings for windows generally fall between 0.20 and 1.20. The lower the U-value, the greater a window’s resistance to heat flow and the better its insulating value.
What is a good PG rating for windows?
In addition to energy efficiency, how can I evaluate a window’s or door’s performance?
| Product performance class | Minimum performance grade (PG) | Minimum water resistance test pressure, Pa (psf) |
|---|---|---|
| Windows and doors | ||
| CW | 30 | 220 (4.50) |
| AW | 40 | 390 (8.00) |
| Unit skylights, tubular daylighting devices, and roof windows |
What is CR rating for windows?
between 1-100
Somewhat lesser-known is the NFRC’s condensation rating (CR) which determines how well a window resists condensation. The CR is a number between 1-100, and it is determined by measuring a window’s interior surface temperature at each of the following indoor relative humidity: 30%
What does Nfrc mean for windows?
National Fenestration Rating Council
The National Fenestration Rating Council (NFRC) operates a voluntary program that tests, certifies, and labels windows, doors, and skylights based on their energy performance ratings. The NFRC label provides a reliable way to determine a window’s energy properties and to compare products.
What are good window specs?
In a cold climate a good U-factor for a window is between 0.17 and 0.39. (That’s between R-6 and R-2.5). Lower is better with U-factor–the opposite of R-value, when higher is better. The low end of that range is only achievable with higher-quality triple-glazed windows–windows with three layers of glass.
What does PG mean for windows?
Performance Grade
A product only achieves a “Performance Grade” or “PG” rating if that product complies with not only the structural loading requirement, but all other performance requirements such as air infiltration resistance, water penetration resistance, ease of operation and resistance to forced entry.
What does PG 50 mean in windows?
∎ CW = Product performance class. (CW took the place of C and HC) ∎ PG50 = Performance grade 50, designates Design. Pressure (DP) of 50. ∎ H = Product type is hung window.
What is a good visible transmittance?
While VT theoretically varies between 0 and 1, most values among double- and triple-pane windows are between 0.30 and 0.70. The higher the VT, the more light is transmitted. A high VT is desirable to maximize daylight.
What is visible light transmittance?
Visible Light Transmission (VLT) is a measurement of the amount of visible light waves that transmit through a material. Measured as a percentage, VLT values for vision glazing, like insulated glass units (IGU) that transmits a direct beam of light, typically range between 40-70%.
What is a good NFRC rating?
A good window generally falls between 0.20 and 1.20. The lower the score of a Solar Heat Gain Coefficient the better as well. That good number for that is between zero and one. Likewise, windows with better air leakage will have a lower score.
What is fenestration U-factor?
When it comes to windows, U-factor is a key figure to consider and comes standard on all National Fenestration Rating Council (NFRC) labels. U-factor indicates how much energy will be lost from a building through its windows by specifying how many BTUs can pass through one square foot of material in an hour.