New Frontier in Glazing: room-side low-e coatings?

Published October 20 in labdesignnews.com.

In this month’s column for Lab Design News, we explored glazing options to make spaces more thermally comfortable.

Windows are an invaluable architectural feature to lab design. They provide daylight and views to the exterior. Many studies support the benefits of windows on occupant mood and productivity. However, windows are five to eight times less resistant to heat transfer than a solid wall, and while the insulative values for windows are improving, they still pale in comparison to those for a solid wall. This poses a two-fold problem—energy loss and the effect of thermal comfort on the occupant. The standard measure to compare a window’s thermal performance is U-value or U-factor. This value measures the heat transmittance through a window. A lower U-value equates to a lower amount of heat transferred through the window.

Read the full article.

Key Diagrams:

This diagrams the temperature profile between a triple-glazed IGU and a double-glazed IGU with a room-side low-e coating. The IGU with the room-side low-e coating has a much lower surface temperature and this can create an issue with downdraft.

This is a computational fluid dynamic (CFD) study completed for an office in a lab building and shows the increased air speed and lower air temperature along the window’s interior surface.

Related:
Cut Your Losses: Envelope Performance and Thermal Comfort
Thermal Comfort and Glazing Design