Two numbers on every quote
Every heat pump quote should list two efficiency ratings: SEER2 for cooling and HSPF2 for heating. They are federal ratings under the Department of Energy’s test procedure, and they belong to a specific matched outdoor unit and indoor coil or air handler.
Bluffline Memphis Heat Pumps lists both, with model numbers for both halves, on every estimate.
In one line each
- SEER2, Seasonal Energy Efficiency Ratio 2: cooling output over a typical season divided by the electricity used. Higher means less power for the same cooling.
- HSPF2, Heating Seasonal Performance Factor 2: heating output over a season divided by the electricity used, including backup heat. Higher means less power for the same heat. Because HSPF2 counts the backup strips the heat pump leans on in cold weather, it also reflects how well the unit holds its output as the temperature falls.
What the 2 changed
Federal test procedures changed in 2023. The new tests assume ducts with more resistance, closer to what real houses have, so the same equipment rates a little lower.
| Old rating | Roughly equal new rating |
|---|---|
| 14 SEER | About 13.4 SEER2 |
| 15 SEER | About 14.3 SEER2 |
| 16 SEER | About 15.2 SEER2 |
| 18 SEER | About 17.1 SEER2 |
| 8.2 HSPF | About 7.0 HSPF2 |
| 9.0 HSPF | About 7.7 HSPF2 |
Why it matters when comparing
An older brochure or an online review that quotes SEER can’t be compared directly with a new quote in SEER2. Compare SEER2 with SEER2, and HSPF2 with HSPF2, or convert the old number using the table above.
The rating belongs to the pair
A heat pump’s rating isn’t a property of the outdoor unit alone. It is listed for a combination: a specific outdoor unit with a specific indoor coil or air handler, tested together and listed in the AHRI directory.
What a mismatch does
Pair a new outdoor unit with an old or unlisted indoor coil and the system may not reach its rating at all. It may also run with the wrong refrigerant metering, which costs efficiency and can shorten the compressor’s life. That is why a heat pump replacement usually changes both halves unless the indoor one is a listed match.
Which number matters more in Memphis
In Memphis, cooling runs from May into October and the humid load is heavy. SEER2 drives more of the annual electric bill than HSPF2 in most houses.
When HSPF2 matters more
- All-electric houses where the heat pump carries the whole winter.
- Houses replacing strip heat, where every heating hour used to cost the most.
On a dual fuel system, where gas carries the cold days, HSPF2 matters less.
Federal minimums and TVA tiers
The floor, the rebate tiers and where typical equipment lands:
| Level | SEER2 | HSPF2 |
|---|---|---|
| Federal minimum for new split heat pumps | 14.3 | 7.5 |
| TVA EnergyRight $500 tier | 15 | Not part of the tier |
| TVA EnergyRight $800 tier | 17 | Not part of the tier |
| Typical two-stage units | About 16 to 18 | About 8 to 9 |
| Typical variable speed units | About 18 and up | About 8.5 and up |
The TVA rebate guide explains the program’s rules, including the contractor requirement and which utilities qualify.
How much a higher rating saves
The savings depend on how much the system runs. A rough way to think about it: going from 15 to 18 SEER2 uses about a sixth less electricity for the same cooling.
Who saves the most
- Large houses that run the AC hard.
- Two-story houses with high upstairs loads.
- Houses with sound, sealed ducts, where the rated efficiency actually reaches the rooms.
Who saves the least
- Small, well-insulated houses with modest cooling loads.
- Houses with leaky or restrictive ducts, which lose part of any rating. Fix the ductwork first.
A Memphis cooling season in numbers
To make the ratings concrete, take a 3-ton heat pump in a Memphis house. Assume it delivers about 65 million BTU of cooling over a summer, roughly 1,800 hours of full-capacity running spread over May to October. At about 12.5 cents per kilowatt-hour:
| Rating | Electricity for the season | Approximate cost |
|---|---|---|
| 14.3 SEER2 (federal minimum) | About 4,550 kWh | About $570 |
| 15.2 SEER2 | About 4,280 kWh | About $535 |
| 17 SEER2 | About 3,820 kWh | About $480 |
| 19 SEER2 | About 3,420 kWh | About $430 |
What the table shows
Each step up the ladder saves something every summer, but the steps are tens of dollars a year, not hundreds. Over 15 years, moving from 15.2 to 17 SEER2 saves roughly $800 in this example, about the size of the price difference between two such units, before the TVA rebate’s extra $300.
The same idea for heating
For an all-electric house that needs about 40 million BTU of heat a winter, moving from 7.5 to 8.5 HSPF2 cuts heating electricity by roughly 600 kilowatt-hours, about $75 a winter at MLGW’s winter rate. In a dual fuel house where gas carries most of the cold, the HSPF2 difference matters far less.
Your numbers will differ
Run hours depend on the house’s size, insulation, ducts, setpoint and the summer. Twelve months of MLGW usage shows how much of your bill is cooling, which tells you how much any rating step is worth to you.
What the ratings don’t tell you
Ratings are a lab number for a matched pair under standard conditions. They don’t measure:
- Humidity removal at Memphis conditions; a variable speed heat pump usually does better than its SEER2 suggests.
- Installation quality: charge, airflow and duct leakage can cost more efficiency than the step between two tiers.
- Noise, which has its own sound ratings.
- Cold-weather capacity, which comes from the maker’s performance tables.
The humidity guide covers the moisture side, and the commissioning checklist covers installation quality.
EER2 and the hottest afternoons
Some quotes also list EER2, the Energy Efficiency Ratio at a single hot condition, 95 degrees outside.
SEER2 averages a whole season of mostly milder days; EER2 shows how efficient the unit is on the hottest afternoons, when the grid is busiest and Memphis houses work hardest.
Why it is worth a look
Two units with the same SEER2 can have different EER2 ratings. In a house that runs hard through long stretches of 95-degree weather, the one with the higher EER2 does better on exactly the days that set the peak of the summer bill. It is a tiebreaker, not a headline number.
Reading an estimate
A good estimate shows, for each option:
- Outdoor and indoor model numbers.
- The matched SEER2 and HSPF2 for that combination.
- The TVA tier it falls in, where TVA applies.
- Single-stage, two-stage or variable speed.
Choosing a tier
Start with the right size and sound ducts; they matter more than the rating.
Then pick the tier where the price step, the rebate and your summer run hours make sense. For many Memphis houses that is 15 to 17 SEER2; for two-story or humid houses, variable speed often earns its place.
Further reading
The heat pump versus central AC guide covers the cooling-only comparison, the cost page has the typical ranges, and the Memphis buying guide puts the decision in order.