If you're looking for the most affordable way to cool an entire house over a long period of time, then central air will be more cost-effective. But when it comes to cooling down a couple of rooms or one floor, a window unit may be the cheaper option, with both a lower cost to install and less energy used to run.
The average window unit uses between 500 and 1,440 watts of electricity in order to run, whereas a central air conditioner in the average-sized home uses around 3,500 watts.
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.
On average, a 10,000 BTU window AC unit will cost anywhere from $200 to $500, whereas purchasing and installing a central air conditioner usually runs anywhere from $4,000 to $8,000. Of course, the actual cost depends on the size of the unit and how efficient it is.
The cost to run a window air conditioner is $0.06 to $0.88 per hour at $0.13 kWh. Unit size, location, hourly usage, and EER will impact the actual average cost. Formula to calculate an accurate estimate: Watts * (hours used) / 1,000 * (Local kWh) = daily cost of running a window unit.
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.
This means an AC unit could cost you from $5.17 to $5.94 per day to run. Or about $155-$178 per month you're running it. Let's say you still have an ideal home setup, but a home that's a little bit less than the size of the average home – around 1900 square feet.
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.
If you're trying to cool a single room, a window unit saves you money compared to central air. However, if you're trying to cool an entire building, running multiple window units is inefficient.
Window air conditioners cool, circulate, filter and dehumidify air in the house. They range in size from small units with a cooling capacity of 5,000 BTUs (enough to cool a small room) to as high as 32,000 BTUs (sufficient to cool a small house with adequate airflow).
Your air conditioning system is one of the biggest culprits behind skyrocketing electric bills. When your air filter is dirty, refrigerant levels are low, your thermostat is faulty or you lack proper maintenance, your A/C system can end up using a lot more energy than it should.
While it's safe to leave the AC running all night. But you must take care of how much energy it consumes or if the cool and comfortable air is spreading equally throughout the room. If you are running your AC for long periods of time then try to keep your home ventilated by turning on a fan.
Heating and cooling: 45-50%
The largest electricity consumer in the average household is your heating and cooling appliance. By a long shot. Central air conditioners and heaters use tons of energy in order to keep your home set to the right temperature.
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.
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.
Portable AC Units typically use more wattage than window units or central units (even though they don't require ducts).
If a standard air conditioner is in good order, it can run continuously without a problem. Wall or window AC units should only run eight to 12 hours before you turn them off. Running your AC nonstop will lead to higher electric bills and more repairs.
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.
leaving it on all day and night is better for the HVAC system because it's less taxing. Should you turn off your AC when on vacation? HVAC experts agree it's better to keep your AC on when you're on vacation, especially if you don't plan to leave any windows open.
You should place outward-facing fans on the warmer side of your home to blow the hot air out and inward-facing fans on the cooler side to draw cool air in, says Barry Jacobs, vice president of product development at Comfort Zone, a home environment product company.
Cons to Keeping Fan Continuously Running:
It could cost you hundreds of dollars a year. The average unit has a 500 watt fan, which uses almost as much energy over the course of the year as a refrigerator, resulting in a $50/month bill.
On average, an air conditioner costs between $0.06 and $0.88 per hour to use. Let's see how much air-conditioning costs every month (assuming it runs for 8 hours per day). The cheapest option is $14.40 per month and $211.20 per month on the high end.
Leave Your Air Conditioner On
You might think you're saving money by turning your AC off when you step out of the house. However, a wave of heat and humidity can sneak into your home in the interim. Therefore, leaving your air conditioner on all day in hot temperatures is more energy efficient.
However, this will depend on various factors, like how often you schedule professional maintenance and how long you use your AC. Running your air conditioner 24/7 puts far more strain on your HVAC system than expected. This speeds up the wear and tear on your AC, effectively shortening its life span.