You'll see a massive reduction in available wattage, instead of two 120v 6k watt legs, you're down to a single 120v 3.6k. watt leg. You can run one AC and perhaps the microwave simultaneously but not the AC, electric water htr, and microwave. You may even trip the pedestal if running the AC and a blow dryer. If the AC has a soft start the pedestal would more likely support a 2 of the 3 combination above. If you have a gas option for the water htr. this would be a good time for it. Worst case, you may have to shutdown the AC while using the microwave or a blow dryer. You'll find out pretty quick.