Calculating the electrical usage and cost of a mini split AC unit is essential for understanding its impact on your energy bills. Mini split air conditioners, also known as ductless systems, are known for their efficiency and flexibility. One of the key metrics to consider when evaluating the efficiency of these units is the SEER2 rating. 

The SEER2 (Seasonal Energy Efficiency Ratio 2) rating measures the efficiency of air conditioning units, with a higher SEER2 indicating better efficiency and lower energy consumption. This article will guide you through the process of calculating the approximate electrical usage and cost of a TOSOT mini split AC unit, using the SEER2 rating and other essential factors.

Understanding SEER2 Ratings

The SEER2 rating is designed to provide a more accurate reflection of the actual power consumption of variable-frequency air conditioners. It takes into account the cooling capacity of the unit and the efficiency of the system. The higher the SEER2 rating, the more efficient the unit is, resulting in lower energy consumption and cost savings.

SEER2 Electricity Cost Calculation Formula

To calculate the electricity cost of a mini split AC unit, you can use the following formula:

Electricity Cost = (BTU/SEER2 rating) x (total annual usage hours/1000) x your electricity rate 

Where:

• BTU is the cooling capacity of the unit.
• SEER2 value is the efficiency rating of the unit.
• Annual usage hours are the total number of hours the unit is used in one year.
• The electricity rate is the cost of electricity per kilowatt-hour (kWh), with the average rate in North America being $0.13/kWh.

This will give you an approximate idea of how much it will cost to run your unit per year. The actual amount of watts the unit(s) use may impact this estimate. 

Example Calculation

Let's consider an example to understand how to use this formula. For the TOSOT 12,000 BTU Mini-Split Heat Pump Air Conditioner-230V, if used for 12 hours a day for 4.5 months a year:

4.5 months x 30 days/month x 12 hours/day = 1620 total hours of run time 

Formula: Electricity Cost = (BTU/SEER2 rating) x (total annual usage hours/1000) x your electricity rate

Electricity Cost = (12000/20) x (1620/1000) x 0.13 = $126.36

For comparison, if you were to use an 18 SEER2-rated unit under the same conditions, the cost would be:

Electricity Cost = (12000/18) x (1620/1000) x 0.13 = $140.40

Heating Cost Calculation

The calculation rule for heating costs is similar, using the Heating Seasonal Performance Factor 2 (HSPF2) rating instead of the SEER2 rating. The HSPF2 rating measures the efficiency of heat pumps, with a higher HSPF2 indicating better efficiency.

For example, if the HSPF2 rating is 8.5 and heating is used for 12 hours per day for 3 months:

3 months x 30 days/month x 12 hours/day = 1080 total hours of run time 

Now take that 1080 hours of run time and plug it into the electricity cost formula: 

Formula: Electricity Cost = (BTU/HSPF2 rating) x (total annual usage hours/1000) x your electricity rate

Electricity Cost = (12000/8.5) x (1080/1000) x 0.13 = $198.21

Conclusion

Understanding and calculating the electrical usage and cost of a mini split AC unit is crucial for managing your energy expenses. By using the SEER2 rating and the provided formulas, you can estimate the annual cost of running your mini split AC for both cooling and heating. Higher SEER2 and HSPF2 ratings lead to greater efficiency and lower energy costs, making them a wise investment for long-term savings. Utilize tools like the SEER2 Savings Calculator to make informed decisions and optimize your energy consumption.