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Seasonal costs

Heating and cooling appliances do not run at their annual average when the weather demands them. These pages raise the duty cycles to match in-season operation and rank what it actually costs.

Why the season changes the answer

Every appliance and category page on this site prices an appliance at its annual-average duty cycle — how much of the year it actually draws power, averaged across warm months and cold. That average is the wrong number in the week you are asking the question. A heat pump that runs a little in October runs almost continuously in a January cold snap, and an air conditioner idle in spring cycles most of a July afternoon.

These two pages raise each appliance’s baseline duty cycle to approximate in-season operation — 60% higher for mid-winter heating and 50% for peak-summer cooling — and show the multiplier openly rather than folding it into the result. The figures come out higher than elsewhere on the site, and, more usefully, the order can change: the cheapest option through a whole season is not always the one that looked cheapest at the annual average.

The ranking is not the wattage order

The single most expensive thing you can do with a seasonal appliance is choose it by the number on its label. Electric resistance heaters all convert power to heat one-for-one, so a 1,500-watt space heater and a 1,500-watt section of baseboard cost the same to run — while a heat pump of similar draw delivers several times the heat per unit of electricity. In summer the trap runs the other way: a ceiling fan and an air conditioner sit far apart on cost but do different jobs, and treating the cheap one as a substitute for the expensive one just leaves a room that is no cooler. Each page below leads with the ranking those distinctions produce, then the reasoning behind it.

What these pages are not

Neither page is a forecast of your bill. Climate, insulation, thermostat habits and the age of the equipment move a real seasonal cost far more than any national average can capture. What these pages answer is the question you can actually settle without knowing your house: given the same assumptions, which option costs less to run through the season, and why. For a number tied to where you live, set your state on any appliance page.