Cost and Energy Saving Potential of Glass Facacde Construction

There are remarkable temperature difference between glass surface and indoor air when temperature is normal winter day temperature in Nordic Countries. Cold surface makes cold wall effect and cold air natural convection. With glass facades in cold climates traditionally has been used radiators or fan coils to improve winter time indoor conditions. Besides of current solutions, there are no guaranteed solution to prevent coldness and cold draught inside building.

Fan coils and radiators heat façade up to 55°C during cold winter day. This makes heat loss double compared to system where glass surface temperature is heated with electricity to room temperature 21°C. Remarkable energy can be saved by using electrically heatable glass in facades in Nordic climate conditions.

Radiators and fan coils needs space from floor area which is very costly and fan coils/radiators needs investment. Glass facades in cold climates can be made remarkable lower costs with electrically heatable glass. Pure façade purchase cost with electrically heatable glass is more expensive than façade without heatable glass, when only pure façade costs are compared. When also necessary compensative HVAC system and space savings are taken account, huge sagings can be reached. Savings from reduced floor space and savings coming from missing fan coils / radiators will make electrically heated glass façade superior compared to non-active glass façade. Total saving from this new façade can be up to 50%.