Don't worry, it's Okay with modern laptops (after approx. 2003). In worst case (high voltage spike when the fridge motor shuts off) only the power supply brick may be damaged.

I see you're also running desktops? Instead of a new PSU it's better to invest into a good UPS unit with large capacity battery. APC has SmartUPS series which provides pure sine wave output your PC's are expecting.

A lot of great info, though! Thanks for sharing!