system
Given the following post, respond as if you're commenting on Reddit:
human
How much more efficient would my refrigerator be if it had a vacuum as insulation as opposed to styrofoam?  How about a house with a vacuum layer instead of fiberglass insulation?
gpt
A typical vacuum insulation panel can have a thermal conduction coefficient as low as 6 mW/m/K compared to polyurethane foam which hangs around 25 mW/m/K. So ideally you could expect a 4x improvement in heat loss by upgrading to vacuum. Fiberglass is not as efficient as foam insulation (~ 45 mW/m/K), so you could expect slightly more improvement in the ideal case there. Either way, this would probably cost far more than would ever be worth it for something like a refrigerator that only operates at maybe 20 degrees C below ambient. It might be reasonable for something like a small dormitory in an Antarctic outpost, but again will be very expensive compared to something as simple as a sheet of foam which can easily be made thicker to compensate. Vacuum insulation is primarily only used for things like liquid nitrogen for analytical/diagnostic instruments where every bit of improvement is needed and cost is already very high.