If an appliance that is rated for 220V is used with a 110v-to-220v transformer in a 110v country, or an appliance that is rated for 110V is used with a 220v-to-110v transformer in a 220v country, how much of the electricity is wasted? That is, how much more will it consume compared to the appliance used in its native current country?
If it matters which type of appliance, let's assume something like a humidifier, dehumidifier, air purifier type.
Best Answer
Something like a dehumidifier which has a fairly high load and a high start up current, will require a larger transformer. Cost and portability will be major considerations.
Smaller appliances with low current draws, will be easier to fit to a small transformer.
For reasonable quality transformers, figure a loss of about 3%.