They're less efficient than central AC and will drastically increase your electricity bills. On average it costs 52 cents per day for a 5,000 BTU window unit and $1.14 per day for a 12,000 BTU unit.
Window unit ACs aren't the most energy efficient way to cool your home (compared to central cooling or a ductless mini-split system). In order to cool an entire home, you would need to run a window AC unit for multiple hours, compared to maybe an hour for a central cooling or mini-split system.
EnergySage estimates that a typical window unit costs roughly $320 (CAD 428) per year to run in areas with a 5-month hot season. Therefore, running a window AC will likely add around $27 (CAD 36) on average to your monthly energy bill.
Central units are more efficient than window units. This means that you get more cooling per kilowatt used. That said, cooling one room will be much cheaper, even with a window unit, than cooling the whole apartment with a central unit.
Compared to newer central air systems or ductless mini split options, many window AC units are not energy efficient. Some of the newer window units can be a bit more efficient than older models, but on the whole, these systems aren't very efficient. This leads to higher energy bills than you get with other AC systems.
Split ACs are ideal for larger rooms and offer quieter operation but require professional installation and higher upfront costs. Window ACs are easier to install and more cost-effective but are noisier and less efficient.
The biggest determinant in how long you should run your AC is whether your home uses central air or a wall/window unit. In general, wall and window air conditioning units with smaller capacities can typically run for up to eight hours at a time before they need to rest.
Utilize Curtains or Blinds to Block Sunlight
During the hot summer months, one effective way to increase the energy efficiency of your window air conditioner is by utilizing curtains or blinds to block sunlight. This simple yet effective method can help keep your room cool and reduce the strain on your AC unit.
Cooling yourself with a fan vs. an air conditioner is significantly more energy efficient and cheaper. Fans use around 1% of the electricity consumed by air conditioners. You could leave a fan running for 24 hours and still use less energy than 15 minutes of air conditioning.
Leaving your air conditioning unit running all day won't typically cause damage to the unit itself, but it can strain the system and result in costly energy bills.
A typical AC fan motor uses about 500 watts when it's running. Therefore, if you run the fan continuously for a 30-day month (720 hours), you would use 360,000 watt hours (720 x 500) or 360 kilowatt hours (kWh). Therefore, the fan uses about 360 kWh per month in the ON mode.
A basic window unit typically has a lower initial cost than other models and is relatively easy to install, but they guzzle energy, straining electricity grids, and can contribute to the planet-warming emissions driving extreme heat.
Many property managers say the bans are to prevent damage from improperly installed units, as well as injury and death caused by units falling from second-story rentals.
On average, a well-maintained and high-quality window AC unit can last anywhere from 10 to 20 years. However, this is just an estimate, and individual units may deviate from this range due to different circumstances.
Generally, Window ACs consume more electricity because they are built as a single unit and often lack advanced energy-saving technologies. They are efficient for small spaces but may lead to higher energy bills if used extensively in larger rooms.
"It's best to avoid placing an air conditioner in a window that gets a lot of direct sun," says Chris Regan, CR's resident air conditioner expert. "It'll be forced to work harder." Look for a window that's shaded by trees, an awning, or another building.
As it turns out, the most efficient way to keep your home cool and the bills low is to leave the AC running—ideally, with the temperature turned up toward the upper 70s.
They're less efficient than central AC and will drastically increase your electricity bills. On average it costs 52 cents per day for a 5,000 BTU window unit and $1.14 per day for a 12,000 BTU unit. It's hard to prevent any gaps and drafts with window AC units. Some cold air will leak out of the gaps in the window.
However, leaving a window AC unit running nonstop could reduce its overall efficiency and lifespan if not used smartly. For homes in South Florida and the Florida Keys, where the heat and humidity can be brutal, running your AC continuously might seem like a necessity.
The average cost per hour to run a window air conditioner is around $0.15. So, if you're running your AC 24 hours a day, you can expect to see a cost of about $3.60 per day on your electricity bill.
Allowing your air conditioner to rest is an excellent way to extend its life and ensure it operates efficiently throughout the years. Air conditioners, like homeowners, require rest in order to recover and perform optimally.
Running for 24 hours straight adds wear and tear to numerous system parts, increasing the risk of untimely failures. Rising repair costs: Every time your air conditioner breaks down, you must pay to repair it.
Best AC Temperature Settings While You Are Home
As you consider the most comfortable room temperature for your lifestyle and family, keep in mind that for each degree that you set your thermostat above 72 degrees, you can save up to 3% on your energy bill.