Fridge and aircon you will need a genset like what bro Jason has replied.
You might get away with a large UPS unit for a small fridge but airconditioning
normally not unless you get the 13amp type of air con units like that of the portable brand, Splendid. This type of aircon does save electricity though somewhat noisy.
Gensets are also noisy, i was exploring having some type of wind/solar power over here so i can take myself or reduce the burden on the grid. Then again, everytime i suggest this, my boss at home will shoot it down, saying i will waste more money than i save given that these technology are still expensive and utilities here are reasonable.
So i basically have UPS units for:
Critical desk/stand fans
Tv and Astro
Critical Printers
Critical fax machine
Critical lights
Internet modem/wifi backed up by Celcom broadband - That way, i can fall back to using laptop and remain working for at least 8 hours even after a power outage with the Celcom broadband plugged in.
2nd floor DC powered water pump, can still bathe
There were about a total of 8 power outages in my 2 plus years here, none really bothered me. Sometimes, my wife had to come and tell me, else the beeps from the UPS units would remind me.
Stairs, i use those self powering on types from Philips that would just power on when they sense movement, good for emergencies or times when i don't need to switch on the lights.
