Heating Vs Cooling: Why Does It Take More Energy To Heat A Home Than To Cool One?

Does heating or cooling use more electricity? Heating a home almost always costs more than cooling because of larger temperature gaps and the physics of HVAC systems.

Most people will agree that paying bills is a dreadful part of life, particularly if you live in a cold region and are paying your heating bill in the dead of winter. While people who experience warmer climes may also get hit with a large air-condition bill in the summer, it is less costly, on average, to cool a home than to heat one. This discrepancy in cost has mystified people for decades, even though both warming and cooling technologies have advanced and become more energy-efficient.

Furthermore, natural gas is the most popular fuel for heating systems, which is cheaper than electricity and other fuel sources, so many people would assume that heating systems would be less expensive, yet that isn’t the case. So… why does it take more energy to keep your house warm than it does to keep your house cool?

Heating And Air Conditioning Systems

Before we dive into the nuances of heating vs cooling, we must briefly review the details of both heating and cooling systems. To begin with, heating systems include furnaces, boilers, heat pumps, space heaters, stoves and fireplaces, among others, but this article will focus on furnaces, which is the most common variety found in North America and Europe. A common forced-air furnace ignites the natural gas or propane in the burner, which then warm a heat exchanger attached to a flue. The heated exhaust is then blown out through the vents of the house, effectively warming all the rooms. Even when a heating system is using natural gas, it still requires a significant energy input to create and maintain that elevated temperature.

Air conditioning systems are primarily driven by electricity, which is a less efficient and more costly form of fuel. Rather than using natural gas directly, the gas must be converted into electricity and then used to power the air-conditioning system, a conversion that results in waste. This results in an even greater cost to the consumer. The air conditioner then draws warm air outside the house, where its heat can be dissipated, before returning to the house in a newly cooled state. While there are variations in design and functionality for both warming and cooling systems, these are the fundamental processes involved in both.

Temperature Variations

Given what we know about how air conditioners and heaters work, and what types of fuel they use, it still may be confusing as to why it costs notably more to warm a house than cool it. However, to get an answer for that, we need to look at the temperature change that is demanded by such systems.

For example, if you live in Washington DC, the average high temperature in the summer is about 87 degrees Fahrenheit. During the winter, the average low temperature is roughly 28 degrees Fahrenheit. Everyone is different, but people generally like to keep their house around 74 degrees Fahrenheit, a number that falls squarely in the middle of “room temperature”. This means that, to achieve 74 degrees Fahrenheit in the summer, the air conditioning must affect an average of 13 degrees of temperature change for comfort. During the winter, the heating system must raise the temperature by an average of 46 degrees Fahrenheit to achieve a comfortable temperature. Clearly, far more energy must be expended to overcome a 46-degree difference than a 13-degree difference.

As an example at the extreme, Las Vegas, Nevada has an average summer high of about 104 degrees Fahrenheit! The average winter low of roughly 30 degrees Fahrenheit. The temperature difference for an air conditioner is about 30 degrees Fahrenheit during the summer, but the temperature difference for a heater is still greater at 45 degrees. In northern areas, sometimes people never need to turn an air conditioner on, but they will have to heat their home for 8-9 months of the year!

Generally speaking, inhabited areas get much colder than hotter. This means that heating systems will have to work harder and burn more fuel to maintain a comfortable temperature during the winter. Air-conditioning systems may need to work hard in the summer in some places, and may use a less efficient form of fuel, but it still doesn’t cost as much as the wintertime heating!

Moving Vs Heating

The other fundamental difference between heating and cooling the home is the process by which they are done. Heating a space requires a machine to make heat, which requires a good amount of energy. Basically, you cannot get warm air from the environment, so you must create it. Turning gas into electric energy, and then turning electric energy into heat energy (for those heating systems using electric power), is a very resource-heavy process.

Cooling a space, on the other hand, requires a machine to move the heat, by taking it out of the house, and replacing it with cool air in an efficient cycle. Some “heat pumps” perform a similar process to heat a house by reversing the cycle and moving warmth indoors. Older heat pumps struggled in very cold weather, but modern cold-climate heat pumps with inverter-driven compressors and enhanced vapour injection now operate efficiently down to roughly -20°C (-4°F) and below, making them an increasingly popular alternative to gas furnaces.

Within the HVAC industry, air-conditioning systems have also made greater strides in terms of energy efficiency than heating systems, due to the basic nature of their function. Heating systems can be greatly benefited by effective insulation throughout a home, such as double-glazed windows, insulation in the roof, walls and attic, and tight seals on all the doors and gaps. Even with a tightly sealed home, heat is inevitably lost, requiring more energy to re-elevate the temperature. On the other hand, when you open a door on a hot day while the air conditioning is on, the AC system can stabilize the temperature more quickly, and with less energetic effort.

Why Can A Heat Pump Be More Than 100% Efficient?

Here is a fact that sounds like it should break the laws of physics: a heat pump can be more than 100% efficient, while a gas furnace never can. Burn a unit of natural gas and, at best, you capture most of the resulting heat, with the rest escaping up the flue. Even the most advanced condensing furnaces top out at around 98% efficiency, and many older units run well below that. You simply cannot get more heat out than the fuel put in.

A heat pump (and the air conditioner it is built from) sidesteps this limit by not making heat at all. As we saw above, it moves heat from one place to another, and moving is far cheaper than creating, which is the very same principle behind your kitchen refrigerator. Engineers measure this with the coefficient of performance, or COP: the units of heat delivered for every unit of electricity consumed. A typical heat pump runs at a COP of roughly 3 to 4 in mild conditions, meaning it delivers three to four units of warmth for a single unit of electricity. That extra energy is not invented out of nowhere; it is simply scooped up from the outside air or the ground. The U.S. Department of Energy estimates that a modern heat pump can cut the electricity used for heating by up to 75% compared with electric resistance heaters.

That single number explains the whole puzzle. Cooling, and heat-pump heating, lean on this multiplier, while a flame-based furnace is stuck at or below 100%. The catch is that COP falls as the outdoor air gets colder and there is less heat to harvest, although modern cold-climate models hold up surprisingly well below freezing.

Does Heating Or Cooling Use More Electricity?

So far we have talked about energy and money in general, but plenty of people really want to know something narrower: which one runs up the electricity bill? The honest answer is that it depends entirely on how your home is heated.

Most American homes do not heat with electricity at all. Natural gas was used in roughly 58% of U.S. households as of 2020, and in those homes the furnace burns gas while only the blower fan draws a trickle of electricity. The air conditioner, by contrast, runs almost entirely on electricity, and air conditioning accounts for about 19% of all the electricity an average U.S. home uses. So if you heat with gas, your air conditioner can easily pull more electricity than your heating does, even though your winter energy bills are still the larger ones overall.

The picture flips in all-electric homes. Electricity has quietly become the most common main heating fuel in the country, powering heating in about 42% of homes by 2024 as natural gas slipped to 47%. Where heating runs on electric baseboards, a furnace coil, or a heat pump, the heating season usually dominates the electric meter. In short, "heating versus cooling" on your power bill is really a question about your fuel, not just your thermostat.

How Much More Does It Cost To Heat A Home?

For all the talk of averages, it helps to put real numbers on just how lopsided the two seasons are. According to the U.S. Energy Information Administration's Residential Energy Consumption Survey, space heating swallowed about 42% of all the energy used in American homes, making it comfortably the single largest end use. Air conditioning, by comparison, accounted for just 9%. Together, those two jobs eat up more than half (around 52%) of a typical household's annual energy.

In other words, averaged across the country, homes burn through more than four times as much energy keeping warm as they do keeping cool, and that ratio is exactly why the heating bill tends to sting more. Of course, the balance shifts with the map. In a hot, humid state like Florida, air conditioning can climb to around 28% of a home's total energy use, while in a cold-winter state like Maine it drops to as little as 2%. A reader in Phoenix or Miami may genuinely spend more on cooling than on heat, but for the average household in the colder, heating-dominated climates typical of much of the US, UK, and Canada, the furnace remains the bigger drain on the wallet.

A Final Word

Depending on where you live, your heating and cooling bills may generate very different levels of financial stress. However, on average, heating bills will empty your wallet faster than air-conditioning costs. Based on the need to overcome colder temperatures in populated areas, and the physical differences of warming air vs. moving it, heating systems simply demand more energy! Even if you only heat a space when you’re using it, and ensure that it is properly insulated, when all the coins are counted, your winter bills will likely still be higher than those you receive in the summer!