I'm certainly no insulation or window expert, but AFAIK argon filled gaps between windows are more common than vacuum. https://vistaza.com/gas-filled-windows-gu

I'm certainly no insulation or window expert, but AFAIK argon filled gaps between windows are more common than vacuum. https://vistaza.com/gas-filled-windows-guide/ https://vistaza.com/gas-filled-windows-guide/