Tubelite upgrades Therml=Block entrance systems with patent-pending thermal separation; doors achieve 0.50 U-value, supporting buildings' energy efficiency and net-zero goals

Architectural building products with high thermal performance are an essential part of meeting increasingly stringent Model Energy Codes for today and tomorrow. High-performance products also contribute to achieve current project’s ambitious energy-efficiency and net-zero requirements. In addition to storefront, curtainwall and window systems, commercial entrance doors also serve valuable roles in high-performing building envelopes.

Helping our clients compete and meet the requirements of energy-driven projects, Tubelite Therml=Block® architectural aluminum entrance systems have been upgraded and expanded to provide our highest thermal performance. Using a new patent-pending “poured over strut” (patent pending) thermal separation construction, Tubelite Therml=Block doors can achieve a 0.50 U-value, based on glazing with a center-of-glass 0.24 BTU/ft²-hr-°F value.

Glass gains with lower U-values

When thermally broken aluminum entrances and other fenestration are matched with high-performance glass, the system performance is further improved in all categories, including lower U-values. Tubelite Therml=Block entrance system can achieve a 0.50 U-value (frame), based on glazing with a center-of-glass 0.24 BTU/ft²-hr-°F U-value.

U-value, also known as U-factor, is a measure of:

• Conduction – heat transfer through a solid, liquid or gaseous material via molecular contact. For example, touching a hot stove. To reduce conduction in windows, add frame thermal barriers.
• Convection – the transfer of heat through the movement of liquids or gases. For example, facing into a cold, north wind. To reduce convection in windows, add enclosed air spaces.
• Radiation – the transfer of heat through space without relying on an intervening medium. For example, the heat of the sun on your face. To reduce radiation in windows, add low-e glass coatings.

U-value = BTUs / Square Foot / °F Differential / Hour – In this formula, BTUs are British Thermal Units, which is the approximate heat required to raise 1 lb. of water 1 degree Fahrenheit, such as from 59°F to 60°F. U-value allows the HVAC engineer to calculate peak loads, as well as energy consumption, for any size fenestration opening, in any climate. When comparing U-values, remember that lower is better.

The three components used to calculate U-value for fenestrations systems are:

• Center of Glass (COG) – typical value is 0.29 BTU/ft2-hr-ºF (low-e insulating glass)
• Edge of Glass (EOG) – typical value is 0.34 BTU/ft2-hr-ºF (aluminum spacer)
• Frame – typical value is 0.90 BTU/ft2-hr-ºF (thermally broken). A frame’s U-value includes heat transfer through surfaces perpendicular to the glass plane.

Be aware that COG is different than “whole system” U-value, which includes frame and EOG areas. In addition to noting total system U-values vs. COG, be cautious not to confuse U-value with R-value, commonly used in wall and roofing applications. R-value is the inverse of U-value. For instance, a U-value of 0.50 would equate to an R-value of 2.0.

Finishing touches

Beyond the exceptional thermal performance of our Therml=Block architectural aluminum entrance systems, these products support a wide range of applications and aesthetic options. They are available with narrow, medium and wide stiles, and up to 10 feet tall, as well as in a broad choice of finishes.

Along with standard anodized and painted finishes, these Tubelite’s specialty finishing options include Copper and Bordeaux Anodize, textured Terra Cotta coatings and Wood Grain finishes. Tubelite Therml=Block entrances also allow for dual finishing options and different colors on the interior and exterior.

New and upgraded Tubelite entrance door products are immediately available. Please visit our entrance product webpages to learn more about the features and benefits of Tubelite Standard and Monumental Entrances, or contact your local Architectural Sales Representative for personalized assistance.