As a high-profile commercial tower in Midtown Manhattan, this 51-story office building faces demanding expectations for energy use intensity, carbon footprint reduction, and occupant comfort. The owner needed an upgrade that would improve thermal performance, reduce HVAC energy and maintenance costs, and meet stringent energy codes including New York Local Law 97— all without disrupting tenants or altering the building’s iconic aesthetic.
After evaluating multiple options, including full window replacement, solar control window film and interior secondary window inserts, the owner decided on LuxWall’s glass-only retrofit solution with Enthermal to address these challenges. LuxWall provided a high-efficiency solution upgraded the facade from single pane bronze glass to Enthermal R18 vacuum insulating technology. The interior retrofit reduced energy costs, enhanced occupant comfort, reduced street noise levels, and minimized tenant disruption while preserving the building’s architectural character.
R-Value
Glass-only retrofit solution
Enthermal transparent insulation can be installed directly into a building’s existing non-thermally broken frames in less than one hour per window – from inside the building, without removing or rebuilding the original frame. Proven glazing components like glazing tape, dry gaskets, and silicone ensure a weather-tight seal.
The result is a dramatic improvement in the windows’ thermal resistance, reducing heat loss in winter and heat gain in summer – key factors in lowering energy costs and improving tenant comfort. By retaining existing window frames, capital cost is reduced by up to 60%, tenant displacement is minimized, and costly full-scale facade renovations can be avoided.
Enthermal impact
The installation demonstrated the immediate and long-term benefits of LuxWall transparent insulation, and outperformed industry accepted energy-modeled expectations. Occupants noted a more comfortable, less drafty and quieter environment thanks to the insulating and noise-reducing effects of Enthermal.
To validate performance, Building Envelope Testing, Inc. (BET), a NYC-based independent measurement and verification firm with a full fenestration and building envelope testing capabilities, compared Enthermal to the building’s existing single- pane bronze glass. Over the seven-day test period, Enthermal was 9° F warmer at the center of glass and 15° F warmer at the edge of glass than the single pane bronze glass. Even with non-thermally broken frames, the total window R-value delivered an 10x improvement, translating into a dramatic 92% reduction in conductive heat loss, from a 12.6 BTU/ft²h to just 1.0 BTU/ft²h with Enthermal. These results demonstrate LuxWall’s glass only retrofit energy impact delivering significant HVAC energy savings, reduced operational costs and noticeable comfort improvements from day one.
