Thermal image of REHAU tilt-turn demonstrates how effectively this design separates warmer air and cooler air in order to achieve optimal energy efficiency.

One often overlooked measure of how well fenestration products perform in commercial buildings is their ability to manage moisture. The American Architectural Manufacturers Association (AAMA) created the Condensation Resistance Factor (CRF) to facilitate comparison of window and door designs. This designates three ways to improve condensation resistance:

  • Use of high performance insulated glass units with special coatings
  • Use of a high performance spacer system in the glass unit
  • Replacement of a highly conductive metal framing system (such as aluminum) with thermally improved framing materials such as uPVC.

Vinyl frames resist condensation, reducing risk of water damage to commercial interiors.

To ensure that Amerimax 4500 Series commercial window and door designs meet the most stringent energy codes in the United States and Canada, REHAU has conducted numerous thermal engineering calculations. These designs have been simulated using up to 20 different glazing, coating and spacer configurations. The following chart summarizes the thermal performance of our designs.

Thermal Performance

1U-factors (and R-values) measure the rate of heat transfer and tell how well the window or door insulates. U-factors (and R-values) generally range from 0.20 (R-5) to 1.20 (R-0.8). The lower the value, the better the window insulates.

2SHGC (Solar Heat Gain Coefficient) measures the fraction of solar energy transmitted and tells how well the window or door blocks heat caused by sunlight. SHGC is measured on a scale of 0-1. The lower the value, the better a product is at blocking unwanted heat gain.

3CRF (Condensation Resistance Factor) measures how well a product resists water build-up. CRF is scored on a scale of 1-100. The higher the value, the less build-up the window allows.