How Much Electricity Does a 5000 BTU Air Conditioner Use?

The Quick Answer (Before We Dive Deeper)

A standard 5000 BTU window air conditioner typically uses 400-600 watts per hour when running continuously. But here's the kicker – real-world usage usually translates to 0.5-1.7 kWh per day depending on runtime. Let's break down why there's such a range and how you can calculate your specific costs.

Breaking Down the Energy Math

1. Understanding BTU-to-Watt Conversion

Every 5000 BTU AC unit has two critical numbers:

• BTU rating: 5000 (cooling capacity)
• EER (Energy Efficiency Ratio): Typically 10-12 for modern units

Using the formula:

Watts = BTU ÷ EER

For a unit with 11 EER:

5000 ÷ 11 = ~455 watts

2. The On/Off Cycle Reality

Here's where it gets interesting – your AC isn't running 24/7. Most units cycle on/off every 15-20 minutes once reaching the desired temperature. Let's say yours runs:

• 50% of the time in mild weather
• 75% during heatwaves

Daily energy use examples:

• Moderate use (8 hours @ 50% runtime): 455W × 4 hours = 1.82 kWh
• Heavy use (12 hours @ 75% runtime): 455W × 9 hours = 4.1 kWh

Cost Calculations Made Simple

Using the U.S. average electricity rate of $0.16/kWh:

Pro Tips for Energy Savings

• Choose units with EER 12+ – they use 20% less power than EER 10 models
• Seal window gaps – drafty installations can increase energy use by up to 30%
• Use smart thermostats – proper temperature management can cut runtime by 40%

When Numbers Lie: Hidden Factors

Your actual consumption might differ because:

• Older units (pre-2015) often have EER ratings below 10
• Dusty filters can increase energy use by 15%
• West-facing rooms require 20% more cooling than north-facing spaces

For the most accurate estimate:

1. Check your unit's yellow EnergyGuide label
2. Multiply wattage by your daily runtime hours
3. Divide by 1000 to get kilowatt-hours