Let’s break down the 17 SEER vs 20 SEER dilemma. As always, investing in higher SEER AC or heat pump will cost more, but you will get energy savings. Let’s look at the 17 SEER vs 20 SEER energy savings (you will also get a savings calculator and chart further on).
Namely, the 20 SEER unit is 17.7% more energy efficient than the 17 SEER unit (that will significantly impact our electricity usage in the next 20 years). Here is how to can estimate 17 vs 20 SEER savings:
Say we are buying a 3-ton AC unit and get these two quotes:
- 3-ton 17 SEER unit will cost $6,700.
- 3-ton 20 SEER unit will cost $7,500.
Which one should go for; 17 SEER or 20 SEER? Can energy savings justify this $800 difference in the initial cost?
Well, to figure that out, we have to calculate how much less electricity the more efficient 20 SEER unit will use compared to a less efficient 17 SEER unit.
With the known SEER rating and AC tonnage (3-ton in our example), we can calculate the average running wattage using this formula:
AC Running Wattage = Tonnage × 12,000 / SEER Rating
Here are the results we get:
- 3-ton 17 SEER unit has an average running wattage of 2,118W. That means it will use 2.118 kWh of electricity per hour. If we run it for 1,000 hours per year, that is 2,118 kWh per day. At a $0.15/kWh electricity rates, that’s $317,70 per year. It will cost us $3,177 in electricity costs to run it for 10 years, and $6,354 in 20 years.
- 3-ton 20 SEER unit has an average running wattage of 1,800W. That means it will use 1.8 kWh of electricity per hour. If we run it for 1,000 hours per year, that is 1,800 kWh per day. At a $0.15/kWh electricity rates, that’s $270,00 per year. It will cost us $2,700 in electricity costs to run it for 10 years, and $5,400 in 20 years.
The energy savings difference in 20 years (presuming 1,000 h/year usage, and $0.15/kWh) is $954 in favor of 20 SEER unit. That is more than an $800 difference in the initial example. The decision between 17 SEER and 20 SEER unit is quite clear here; you should go for 20 SEER unit.
Now, your electricity rates might not be $0.15/kWh. You might be looking at 2-ton, 4-ton, or even a 5-ton unit.
To help you calculate 17 SEER vs 20 SEER yearly energy savings, we have prepared a neat calculator. You insert the AC tonnage you are looking for and your electricity rates, and the calculator will automatically tell you how much you are saving every year if you choose 20 SEER over 17 SEER unit.
Below the calculator, we have also calculated 1-year, 10-year, and 20-year savings for 1 ton, 1.5 ton, 2 ton, 2.5 ton, 3 ton, 3.5 ton, 4 ton, 5 ton, 6 ton, 7 ton, and 8 ton units (presuming 1,000 h/year usage and $0.15/kWh electricity rates), and summarized the result in a colorful chart:
17 SEER Vs 20 SEER Savings Calculator
Here is a quick example of how you can use this calculator:
Let’s say you are looking to get 4 ton AC unit, and you are wondering how much energy savings you can expect to get if you choose a 20 SEER unit over a 17 SEER unit. Your electricity rates are $0.20/kWh. Just slide the 1st tonnage slider to ‘5’, and the 2nd electricity rates slider to ‘0.20’, and you get the result:
Compared to 17 SEER unit, the 20 SEER unit will cost $84.71 per year less to run. That’s $847,10 savings in 10 years, and $1,694.20 savings in 20 years.
If the difference in the cost of 17 SEER vs 20 SEER (cheaper vs pricier) is less than $1,694.20, you should opt for a 20 SEER unit. On the other hand, if the difference is more than $1,694.20, you should opt for 17 SEER unit.
Here is the promised 17 SEER vs 20 SEER savings chart that will help you out as well:
17 SEER Vs 20 SEER Chart For 1-8 Ton Air Conditioners And Heat Pumps
| Unit Size (Tonnage): | 1-Year Savings ($): | 10-Year Savings ($): | 20-Year Savings ($): |
| 1 Ton | $15.88 Savings Per Year | $158.80 Per 10 Years | $317.60 Per 20 Years |
| 1.5 Ton | $23.82 Savings Per Year | $238.20 Per 10 Years | $476.50 Per 20 Years |
| 2 Ton | $31.76 Savings Per Year | $317.60 Per 10 Years | $635.30 Per 20 Years |
| 2.5 Ton | $39.71 Savings Per Year | $397.10 Per 10 Years | $794.10 Per 20 Years |
| 3 Ton | $47.65 Savings Per Year | $476.50 Per 10 Years | $952.90 Per 20 Years |
| 3.5 Ton | $55.59 Savings Per Year | $555.90 Per 10 Years | $1,111.80 Per 20 Years |
| 4 Ton | $63.53 Savings Per Year | $635.30 Per 10 Years | $1,270.60 Per 20 Years |
| 5 Ton | $79.41 Savings Per Year | $794.10 Per 10 Years | $1,588.20 Per 20 Years |
| 6 Ton | $95.29 Savings Per Year | $952.90 Per 10 Years | $1,905.80 Per 20 Years |
| 7 Ton | $111.18 Savings Per Year | $1,111.80 Per 10 Years | $2,226.60 Per 20 Years |
| 8 Ton | $127.06 Savings Per Year | $1,270.60 Per 10 Years | $2,541.20 Per 20 Year |
As we can see, at these conditions, choosing 20 SEER unit over 17 SEER unit will give us:
- $15.88 to $127.06 savings per year.
- $158.80 to $1,270.60 savings in 10 years.
- $317.60 to $2,541.20 savings in 20 years.
With these energy savings calculations, you are now well equipped to figure out if you should go for 17 SEER or 20 SEER unit. If you need a bit of insight, you can give us some quotes and figures (like electricity rates) in the comments below, and we will help you out.