# What do SEER2 and HSPF2 mean on a heat pump?

> What SEER2 and HSPF2 ratings mean on a heat pump, how they differ from the old SEER and HSPF numbers, which tier suits Memphis, and why matched pairs matter.

URL: https://blufflinememphisheatpumps.com/guide/seer2-hspf2-explained/

Learn

The two numbers on every heat pump quote, what changed when they got a 2, and how much a higher rating is worth in a Memphis house.

Last Updated: November 12, 2026

The short answer

SEER2 measures cooling efficiency over a season and HSPF2 measures heating efficiency, both under the federal test procedure that took effect in 2023 with tougher conditions than the old SEER and HSPF. Higher is better. In Memphis, where cooling runs half the year, SEER2 matters most; 15 and 17 SEER2 are also TVA's rebate tiers.

Key takeaways

- SEER2 is seasonal cooling efficiency; HSPF2 is seasonal heating efficiency.
- The 2 versions use tougher test conditions, so the numbers are lower than old SEER and HSPF for the same unit.
- Ratings belong to a matched pair, outdoor unit plus indoor coil or air handler, not one half.
- In Memphis, cooling hours make SEER2 the bigger driver of bills.
- TVA EnergyRight's rebate tiers sit at 15 and 17 SEER2.

## 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](https://blufflinememphisheatpumps.com/) 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](https://blufflinememphisheatpumps.com/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](https://blufflinememphisheatpumps.com/dual-fuel-heat-pump/) 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](https://blufflinememphisheatpumps.com/guide/tva-energyright-heat-pump-rebate/) 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](https://blufflinememphisheatpumps.com/heat-pump-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](https://blufflinememphisheatpumps.com/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](https://blufflinememphisheatpumps.com/guide/heat-pump-humidity-control/) covers the moisture side, and the [commissioning checklist](https://blufflinememphisheatpumps.com/guide/heat-pump-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](https://blufflinememphisheatpumps.com/guide/heat-pump-vs-central-ac/) covers the cooling-only comparison, the [cost page](https://blufflinememphisheatpumps.com/heat-pump-installation-cost/) has the typical ranges, and the [Memphis buying guide](https://blufflinememphisheatpumps.com/guide/memphis-heat-pump-buying-guide/) puts the decision in order.

## Questions about this guide

### How does SEER2 compare to the old SEER rating?

For the same equipment, SEER2 reads roughly 4 to 5 percent lower than SEER, because the new test assumes more realistic duct resistance. A unit once sold as 16 SEER rates around 15.2 SEER2. Compare SEER2 to SEER2 only.

### What is the minimum SEER2 for a heat pump in Tennessee?

Federal minimums for new split-system heat pumps in the Southeast are 14.3 SEER2 and 7.5 HSPF2. Tennessee follows the federal standard, and TVA's rebate starts higher, at 15 SEER2.

### Is a higher SEER2 always worth paying for?

Not always. The gain is largest in houses that run the AC hard and have sound ducts. In a small, efficient house or on leaky ducts, the extra cost may take many years to recover.

## Related service

- [Service**Variable speed heat pumps** Long, slow runs that pull more water out of a Memphis summer and keep two-story houses even.](https://blufflinememphisheatpumps.com/variable-speed-heat-pump/)

## More guides

- [Cost Guide**How does the TVA EnergyRight heat pump rebate work in Memphis?** Who qualifies, which equipment tier pays what, the contractor rule, and what to expect on the Mississippi and Arkansas side.](https://blufflinememphisheatpumps.com/guide/tva-energyright-heat-pump-rebate/)
- [Decision Guide**Should you replace your central AC with a heat pump?** The same cooling, a little more cost, and a second way to heat. When the switch pays and when a plain AC is still the right buy.](https://blufflinememphisheatpumps.com/guide/heat-pump-vs-central-ac/)
- [Learn**Does a heat pump remove humidity from a Memphis house?** Why 72 degrees can still feel clammy, where the water goes, and the four things that decide how dry a heat pump keeps the house.](https://blufflinememphisheatpumps.com/guide/heat-pump-humidity-control/)
- [Decision Guide**How do you buy the right heat pump for a Memphis house?** The whole decision in the order you meet it, from the system you have now to the readings you should get at start-up.](https://blufflinememphisheatpumps.com/guide/memphis-heat-pump-buying-guide/)

## Get an estimate for your house

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