May 17, 2021
Energy Usage in California

You are making a huge investment in your home when you buy a new cooling system, so you want to feel confident that you make the best choice, both for your budget and your family. The process of selecting a new AC unit brings to light a dizzying array of options, such as energy efficiency, cost, wattage, BUTs, and so much more. At White Mechanical, Inc., we help homeowners in Foothill Ranch, Orange County, and neighboring communities in California find the solutions that fit their needs. Our team understands HVAC systems and provides expert guidance throughout the buying process.

Why AC Size Matters

One of the factors for finding a good cooling system for your home is size, and this is described in several different ways. The reason why you want to pay extra attention to size is that it affects your budget upfront, as well as for years to come. If you buy a unit that is too small, you run the risk of a cooling system that uses up more energy to keep you comfortable. Buying an AC that is too large means that you invested too much upfront and will never use the unit to its full capacity.

Metrics for AC Size

When we refer to size for a cooling system, we don’t necessarily mean the physical size. Some of the metrics that indicate size are:

  • Seasonal Energy Efficiency Ratio (SEER)
  • British Thermal Units (BTUs)
  • Watts
  • Tonnage
  • Physical Dimensions

What Are Watts?

Although SEER ratings and BTUs are key aspects to consider for your new AC system, watts are just as important. The topic is rarely discussed, so few homeowners understand the metric. As with amps, volts, and ohms, watts are another way to describe power. Watts is a calculation that equals one volt multiplied by one amp. Before you pull out a calculator, there is an easier way to understand watts. The term describes the rate at which power moves through an electrical system, unit, or component. Higher watts mean that power moves more quickly, and lower watts mean that power moves more slowly. Using a lightbulb as an example, when power moves slower, the bulb is dimmer. When power moves faster, this is when you have the bright light of a 100W bulb.

Why Are Watts Important for AC Units?

You are familiar with watts from the lightbulbs that you use in your home. More watts typically mean brighter light, but additional light uses more energy, which means you pay more in utilities. The same concept applies to heating and air conditioning, but on a much larger scale. If you are wondering how long it will take to see a return on your investment, watts are a good place to start.

How Are Watts Used in Air Conditioning?

The rate at which your home cooling system uses energy to keep you comfortable is valuable information when you are evaluating true energy efficiency. The watts are used with the amps and volts to get a good baseline understanding of how many kilowatts per hour are used to operate the unit. If the unit is not labeled with watts, you can multiply the volts and amps, then convert the number into kilowatts per hour. Using the rates for your electric company, you can then determine how much it will cost each hour to run the unit.

Total Watts for Cooling

Several components of your cooling equipment use energy, and a common mistake among homeowners is that they only look at the compressor. When you are determining the number of watts for your new unit, be sure to include power needs for all components. If you aren’t sure what needs to be included, give us a call, and we will walk you through the process. You can also schedule a time for one of our technicians to come by and calculate watts and energy use for you.

BTUs and Watts

Another metric that is detailed on new AC systems for Southern California homes is BTUs. One BTU is the amount of heat that is needed to raise the temperature of one pound of water by 1°F. There are approximately 3.41 BTUs per watt, so you can divide the BTUs by this number to calculate watts.

BTUs, SEER Rating, and Watts

If the label on the AC system shows the SEER rating and BTUs, calculating watts is a bit more straightforward. Divide the number of BTUs by the SEER rating, and the result is the number of watts. You can then convert that to kilowatts and use the rate from your electric company to determine a baseline for operating the unit during the summer.

Average Watts for Home AC Systems

If you only need an idea of how much the energy costs are for residential AC units, you can use a quick reference as a general guide. Before you purchase a new system, though, be sure to make a more detailed calculation, so you aren’t disappointed with your choice. Here are the watts for some of the more common residential air conditioners in Southern California.

  • 5,000 BTU cooling system uses between 417 and 625 watts per hour
  • 6,000 BTU cooling system uses between 500 and 700 watts per hour
  • 8,000 BTU cooling system uses between 667 and 1,000 watts per hour
  • 10,0000 to 12,000 BTU cooling systems use between 833 and 1,500 watts per hour
  • 15,000 to 18,000 BTU cooling systems use between 1,250 and 2,250 watts per hour

Reasons to Choose High-Wattage AC Systems

Given the higher cost of operation for AC systems that use more watts, why would you want to buy one of these units? Why not just buy the lowest watt model? Watts do serve a purpose, and the intent behind calculating the number of watts for a particular unit is to help you understand the cost of operation. You should never skimp on watts as a way to save money now or in the future. A better way to choose your new AC system is with BTUs and SEER ratings, then only use watts to understand how much to budget for electricity during the summer months.

Combine a New AC With Other Upgrades

If you find that your new AC does require more watts than what fits comfortably in your budget, the experts at White Mechanical, Inc. can help. We offer many upgrades to HVAC systems that reduce overall energy use in Foothill Ranch homes. One product that can help save money is a programmable thermostat, and another is a zone system. To learn more about these and other options, call us to speak with one of our cooling experts.

Residential Cooling Experts

Since 2002, White Mechanical, Inc. has provided professional HVAC services to homeowners in Foothill Ranch, Orange County, and surrounding areas of southern California. No matter what you need, we are here for you. We offer installation, repairs, and maintenance, including 24×7 emergency repairs. We also carry a line of top-notch AC and heating systems to simplify your buying process. Call us today to learn more, and be sure to ask about our ceiling insulation, sheet metal fabrication, attic, and duct services.

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