These are typical estimates, not your appliances' exact numbers. Motor-driven appliances (pumps, compressors, fans) draw far more power for a fraction of a second when they start than while running — that startup surge, not the running load, is usually what determines the generator size you actually need. Check the nameplate or owner's manual on your own equipment where it matters, and for a permanent whole-house installation, have a licensed electrician confirm the sizing before you buy.