Small heaters for winter at home

Japanese homes tend to be cold in winter, and the air conditioner alone sometimes isn't enough, so a lot of people add a small heater or two. It's worth working out the electricity cost before you buy. Below I use ¥31 per kWh, the rate the appliance industry uses for its estimates; your actual rate depends on your power company.

Ceramic fan heaters warm up fast. On high they typically draw around 1200W, which comes to about ¥37 an hour, so leaving one on all night doesn't pay off. They're better for short stretches in the toilet, the changing room by the bath, or under your desk. To heat a whole room, the air conditioner is still cheaper to run.

Electric blankets are the cheapest, only a few yen for a whole night. If your bed is too cold to fall asleep in, try one of these first. Kotatsu (こたつ) heaters are mostly rated around 500W, but they regulate their own temperature, so in practice they cost anywhere from a few yen to a dozen or so yen an hour. Amazon has lots of kotatsu from Yamazen and Iris Ohyama; some sell the table and the quilt separately, so check before you order.

A single wall outlet in Japan can generally handle up to 1500W, so running a fan heater at the same time as a hair dryer or microwave can easily trip the breaker. It's best to plug high-wattage appliances into separate outlets.