SEER2 and HSPF2 measure two different jobs. SEER2 rates how efficiently an air conditioner or heat pump cools your home over a season. HSPF2 rates how efficiently a heat pump heats it. A higher number on either one means less electricity used for the same comfort, but the two numbers cannot be swapped for each other, and in Colorado Springs, where winters are long and cold, the heating number deserves at least as much attention as the cooling one.
This guide explains what each rating measures, how the “2” versions differ from the older SEER and HSPF, what the numbers can and cannot tell you about your utility bill, and how to use both when you compare replacement systems on the Front Range.
TL;DR
- SEER2 is the seasonal cooling rating for air conditioners and heat pumps. HSPF2 is the seasonal heating rating for heat pumps only.
- The “2” ratings come from a tougher test, so the same equipment often scores lower than it did under the old SEER and HSPF scale. Do not compare old and new numbers directly.
- For a Colorado Springs home, check HSPF2 and cold-weather performance as closely as SEER2, because heating carries most of the load here.
- Ratings are lab-based. Sizing, ductwork, installation quality and thermostat settings decide how much of the rating you actually see on your bill.
- A gas furnace uses a different rating, AFUE, so HSPF2 only enters the picture if you are considering a heat pump.
Table of Contents
- The short version: cooling versus heating
- What SEER2 measures
- What HSPF2 measures
- HSPF2 vs SEER2 at a glance
- How the “2” ratings differ from SEER and HSPF
- What counts as a good rating
- Why Colorado Springs buyers should look past SEER2
- How much do the ratings affect your bill?
- A worked comparison: three paths for a replacement
- Heat pump options and what the numbers mean
- Heat distribution and your overall heating plan
- Our perspective
- How to compare quotes using both ratings
- Common questions about reading the ratings
- Ready to compare equipment for your home?
- FAQ
- Sources
The short version: cooling versus heating
Think of the two ratings as a report card with two subjects. SEER2 grades summer. HSPF2 grades winter. A heat pump is the only common residential system that earns both grades, because it moves heat out of your house in summer and into your house in winter using the same equipment.
An air conditioner has a SEER2 rating and nothing else, because it only cools. A gas furnace has an AFUE rating, which is a different measure of how much fuel becomes heat. So if you are replacing a central AC and a furnace as a pair, SEER2 and AFUE are the numbers you will compare. If you are looking at a heat pump to do both jobs, SEER2 and HSPF2 come as a set.
The ENERGY STAR program states the split plainly: HSPF2 measures a heat pump’s seasonal heating performance, while SEER2 measures its seasonal cooling performance. Most of the confusion in this topic comes from people treating them as two versions of one number. They are two numbers for two seasons.
What SEER2 measures
SEER2 stands for Seasonal Energy Efficiency Ratio 2. ENERGY STAR defines it as the total heat removed from the conditioned space during the annual cooling season, divided by the total electrical energy the air conditioner or heat pump consumes over that season. A higher rating indicates more efficient equipment and can mean lower energy costs.
Two features of that definition are worth understanding.
First, it is a seasonal average. SEER2 is not the efficiency of the unit on the hottest afternoon of July. It blends a range of outdoor temperatures into a single figure, which is why it works well as a way to compare models but poorly as a prediction of your exact bill.
Second, it measures cooling only. A heat pump with an excellent SEER2 can still be a mediocre heater, and vice versa. The SEER2 number tells you nothing about how the same machine behaves when it is 15 degrees outside.
Why SEER2 matters a little less in Colorado Springs
Colorado Springs sits at roughly 6,000 feet, with dry air, cool nights and a cooling season that is shorter and milder than in much of the country. Many homes here run their air conditioning for a modest number of weeks a year, and some rely on evaporative coolers. That does not make SEER2 irrelevant. It simply means a point of SEER2 saves you less per year here than it would in a humid, hot-summer city, while the heating side of the ledger runs for months.
What HSPF2 measures
HSPF2 stands for Heating Seasonal Performance Factor 2. ENERGY STAR describes it as the total space heating required during the heating season, in Btu, divided by the heat pump system’s total electrical energy use over that season, in watt-hours. In plain terms, it is the amount of heat delivered for each unit of electricity consumed across a winter.
A higher HSPF2 means the heat pump delivers more heat per kilowatt-hour. Because a heat pump moves heat rather than creating it, a good one can deliver several times more heat energy than the electrical energy it uses. The rating captures that over a whole season of changing outdoor temperatures.
Only heat pumps carry an HSPF2. If someone quotes you an HSPF2 for a furnace or an air conditioner, the number does not apply. If you are comparing a heat pump with a gas furnace, you are comparing across two different scales, which is where operating cost and fuel prices have to do the work. Our guide to heat pump versus gas furnace cost in Colorado Springs walks through that comparison.
HSPF2 vs SEER2 at a glance
| SEER2 | HSPF2 | |
|---|---|---|
| What it rates | Seasonal cooling efficiency | Seasonal heating efficiency |
| Equipment it applies to | Air conditioners and heat pumps | Heat pumps only |
| Season covered | Summer cooling season | Winter heating season |
| Higher number means | Less electricity for the same cooling | Less electricity for the same heating |
| Furnace equivalent | None | AFUE rates a gas furnace, on a different scale |
| Most useful for | Comparing air conditioners and heat pumps for summer use | Comparing heat pumps for winter use |
The row to remember is the last one. Use SEER2 to compare cooling, use HSPF2 to compare heating, and never add or average them into a single score.
How the “2” ratings differ from SEER and HSPF
If you have seen older numbers on a brochure or a neighbor’s quote, the “2” versions will look lower. That is expected, and it is not a sign that newer equipment is worse.
The U.S. Department of Energy changed the test procedure, and ratings under the newer M1 procedure became mandatory from January 1, 2023. The biggest change is how much air resistance the unit is tested against. The new procedure generally raises the tested external static pressure to 0.5 inches of water column, up from roughly 0.1 to 0.2 under the old procedure, which better represents the resistance of real ductwork. The heating test also specifies required conditions at 47°F, 35°F and 17°F for certain equipment, with an optional 5°F steady test in the final rule.
The practical result is that a more demanding test produces numerically lower scores. New York State’s clean heat program notes that M1 ratings are often numerically lower than legacy ratings, and the lower number does not itself mean the equipment became less efficient.
Can you convert old numbers to new ones?
Only roughly. EPRI, the energy research institute, states that legacy SEER and HSPF values cannot be directly compared with SEER2 and HSPF2 because the test procedures and calculations differ. RESNET publishes a table of conversion factors, and it uses different factors for different equipment types, so there is no single multiplier that works for everything.
What this means when you shop: compare SEER2 with SEER2 and HSPF2 with HSPF2. If a quote mixes old and new ratings, ask for the current ones so every option sits on the same scale.
What counts as a good rating
There is no single “good” number, because the answer depends on the type of system and what you want from it. ENERGY STAR gives useful reference points for heat pumps. Its criteria for standard split-system heat pumps are at least 7.8 HSPF2, 15.2 SEER2 and 11.0 EER2, while single-package equipment needs at least 7.2 HSPF2, 15.2 SEER2 and 10.0 EER2.
EER2 is a third number you may see. ENERGY STAR defines it as the ratio of average cooling delivered to average electrical energy consumed, a snapshot of efficiency at a set condition rather than a season-long average. For a dry-climate buyer it is a useful secondary check on cooling performance, but SEER2 and HSPF2 remain the headline figures.
The ENERGY STAR criteria also include cold-climate designations with higher heating standards. That is the part Colorado buyers should pay attention to, and we cover it next.
Why Colorado Springs buyers should look past SEER2
It is easy to shop by SEER2 alone, because it is the number most prominently advertised and the one most people have heard of. In a cold, high-altitude climate that habit can steer you wrong.
ENERGY STAR’s own structure shows why. Certification and the cold-climate designation incorporate HSPF2 and, for cold-climate products, low-temperature performance requirements, not just a cooling score. The cold-climate criteria listed there are a higher bar for heating performance than the standard ones.
A local example shows the same thinking. Colorado utility rebate programs tend to set heating-focused requirements. United Power’s heat pump rebate page, for instance, lists minimum air-source requirements of 8.5 HSPF2 for non-ducted systems and 8.1 HSPF2 for ducted systems, along with 15.2 SEER2, with rebates effective January 1, 2026. United Power serves a different part of the state than Colorado Springs, so check your own utility’s current rebate terms, but the pattern is instructive: when the incentive is designed for Colorado, HSPF2 carries real weight.
So when you compare two heat pump options, a practical order of questions looks like this:
- What is the HSPF2, and is the model designed for cold climates?
- How does it hold up at low outdoor temperatures, not only at 47°F?
- What is the SEER2, and does it meet the level you want for summer?
- What backup heat will it use on the coldest nights, and how much electricity will that draw?
That last question matters because resistance heating strips use far more electricity than the heat pump itself. A system that leans on them often will not deliver the savings its HSPF2 suggests.
How much do the ratings affect your bill?
Higher ratings do reduce energy use, and the difference can be substantial when you compare the bottom of the range with the top. The Department of Energy’s purchasing guidance for air-source heat pumps gives modeled examples: a 24/11 SEER2/HSPF2 system using 7,683 kWh and costing $846 a year, compared with 12,304 kWh and $1,354 for a 14.3/7.5 system. A second example in the same guidance compares 7,029 kWh and $774 with 11,352 kWh and $1,250.
Two cautions keep those numbers in perspective. They are modeled cases under stated assumptions, not predictions for your house. And the 24/11 system is at the very top of the efficiency range, well above what most homes will install. The gap between, say, a mid-range and a high-efficiency unit will be smaller than the gap between the very best and the minimum.
What the ratings cannot capture is just as important. Actual energy use also depends on climate, equipment sizing, installation quality, ductwork, thermostat operation and how much resistance heating runs. That is why two neighbors with the same model can see different bills.
What drives results beyond the label
Sizing comes first. A unit that is too large cycles on and off, wearing itself out and failing to dehumidify or hold temperature evenly. A unit that is too small runs constantly and leans on backup heat. A proper load calculation for your specific home, not a rule of thumb by square footage, is the foundation.
Ductwork comes second. Leaky or undersized ducts waste a share of whatever the equipment produces. The reason the test procedure moved toward higher static pressure is that real ducts push back on the system. If your ducts are in poor shape, a high rating will not make up for it.
Installation quality comes third. Refrigerant charge, airflow and commissioning all affect whether the unit performs near its rating. This is the unglamorous part of the job, and it is where a careful installer earns the price.
Then there are everyday habits. Setting a heat pump thermostat back by large amounts and then calling for a big recovery can trigger backup heat. Steady, modest adjustments usually serve a heat pump better.
A worked comparison: three paths for a replacement
Suppose you have a 20-year-old central air conditioner and a gas furnace in a Colorado Springs home, and one of them fails. You have a few sensible paths, and the ratings play different roles in each.
Path one is to replace the air conditioner and keep the furnace. Here SEER2 is the only rating that matters for the new equipment, and AFUE continues to describe your furnace. Our air conditioner pricing page lists a 14 SEER2 single-stage air conditioner from $5,500 and a 16+ SEER2 single-stage unit from $6,500. Given Colorado Springs’ shorter cooling season, many homeowners find the lower rating adequate, while others prefer the higher rating for comfort and lower summer use.
Path two is to replace both with a heat pump and keep the furnace as a backup, often called a dual-fuel setup. Now SEER2 and HSPF2 both matter, and the furnace covers the coldest hours. The heat pump handles the milder shoulder seasons efficiently, and the furnace takes over when temperatures drop far enough that gas becomes the better choice.
Path three is to replace the furnace and air conditioner together with a high-efficiency furnace and AC pair. SEER2 and AFUE are your two numbers, and HSPF2 does not apply. Our furnace pricing page lists a 96% AFUE variable speed condensing gas furnace from $6,500 and a 98% AFUE modulating gas furnace from $8,250, among other options.
None of these is automatically right. The best fit depends on your home’s insulation, ductwork, how you use your space and what you pay for gas and electricity. The honest way to decide is to compare the full installed cost and the likely yearly operating cost of each path, not to chase the highest single rating.
Heat pump options and what the numbers mean
If a heat pump is on your list, the ratings on the model tell you how it is built. We install single-stage, three-stage and variable-capacity heat pumps, and the difference between those types shows up in how smoothly and efficiently they run.
| Heat pump type | SEER2 | Starting price |
|---|---|---|
| Single-stage | 15 | From $6,500 |
| Three-stage | 17 | From $8,500 |
| Variable | 18 | From $10,000 |
These are published starting prices for equipment and installation from our pricing page. The final figure depends on your home. A single-stage unit runs at full output whenever it is on. A multi-stage or variable unit can match its output to the demand of the moment, which usually means steadier temperatures and fewer starts and stops. Ask for the HSPF2 of each model alongside the SEER2 so you can see the heating side next to the cooling side.
If you want to see where a project would land before you call, the HVAC installation cost calculator gives a starting point, and our heat pump replacement service page explains how a replacement project goes from visit to commissioning.
Heat distribution and your overall heating plan
A rating describes the equipment, but comfort depends on how heat reaches the rooms. Ducted forced-air systems, ductless mini-splits and in-floor systems all behave differently, and each suits different homes. If you are weighing options for particular rooms or an addition, this radiant floor heating guide explains how floor-level heat works and what it asks of a home’s design.
For most Colorado Springs houses with existing ducts, the practical question is whether the current duct system can carry a heat pump’s airflow. A heat pump often moves more air at lower temperatures than a gas furnace does, so duct size and condition matter. That is a point to verify during an in-home visit, before you sign.
Our perspective
We install and repair heating and cooling equipment in Colorado Springs and the surrounding Front Range communities, and the single most common mistake we see in rating conversations is shopping by one number. SEER2 gets the attention because it is on every air conditioner label, but a home at this altitude spends far more of the year heating than cooling.
That is why we start with the house, not the brochure. We look at the home’s size and insulation, the condition of the ducts, how the family uses the space, and what the heating season demands. Then we talk through which rating combination makes sense: a higher SEER2 if summer comfort is the priority, a stronger HSPF2 and cold-weather performance if a heat pump will carry the winter, or a high-AFUE furnace paired with a good air conditioner when gas remains the better fit.
Our approach is flat-rate pricing with no hidden fees, so the number you are quoted is the number you plan around. Our technicians are NATE-certified, and our team brings more than 40 years of combined experience to climate conditions that are different from the rest of the country. A rating is only a starting point. Careful sizing, a clean installation and honest advice are what turn a rating into comfort and lower bills.
Owner
How to compare quotes using both ratings
When you have two or three proposals in hand, a few habits make them easier to read side by side.
First, ask each contractor to list the SEER2 and, for heat pumps, the HSPF2 of the exact model, not just the product line. Lines often include several models with different ratings.
Second, confirm that every number is on the same scale. If one quote cites a SEER and another a SEER2, the first will look better than it is. Since legacy and current values cannot be directly compared, ask for the current rating.
Third, check whether the model is designated for cold climates, and whether the proposal includes backup heat and what kind.
Fourth, look at what is included beyond the equipment: load calculation, duct inspection or repair, permit, thermostat, commissioning and warranty terms. A lower price that leaves out the duct work or the load calculation is not truly lower.
Fifth, ask about incentives. Federal, state and utility programs change, and many tie eligibility to specific SEER2 and HSPF2 thresholds. Check your utility’s current rebate page and the official ENERGY STAR listings for the model before you decide, since requirements and amounts are updated over time.
Common questions about reading the ratings
Is a higher HSPF2 always better?
A higher HSPF2 means more heat delivered per unit of electricity over a season, so on efficiency alone, yes. But it usually comes with a higher purchase price and, often, more advanced equipment such as variable-speed compressors. The right choice weighs the extra cost against how much you will heat with the heat pump, which is why a cold-climate home with high winter use benefits more than a home that rarely runs its heat pump in winter.
Do I need to worry about HSPF2 if I keep a gas furnace?
If the furnace will do the heating, your heat pump’s HSPF2 matters less, though it still describes how the heat pump behaves in milder weather when it is running. In a dual-fuel setup, SEER2 and the furnace’s AFUE do most of the work on the label.
Why do new ratings look lower than my old system’s?
The test is stricter. The updated procedure uses higher duct resistance and revised heating test conditions, so the same equipment earns a lower number than it would have under the old scale. The lower figure reflects a more realistic test, not a weaker machine.
Ready to compare equipment for your home?
If you are replacing an air conditioner, a furnace or both, we can walk through the ratings on each option, measure what your house actually needs and give you a flat-rate quote. We offer heat pumps, air conditioners and gas furnaces across a range of efficiency levels, so the recommendation follows your home and budget, not a single number.
See published starting prices on our air conditioner and heat pump pricing and furnace pricing pages, or start a project through our HVAC installation service. For a broader look at the local picture, read whether a heat pump is worth it in Colorado, or our explainer on what SEER2 means for your bill. You can also reach us any time at strongheatingcooling.com.
FAQ
What is the main difference between HSPF2 and SEER2?
SEER2 rates a system’s seasonal cooling efficiency, and HSPF2 rates a heat pump’s seasonal heating efficiency. Air conditioners have only a SEER2. Heat pumps have both. You compare each rating against others of the same type, and you never combine them.
Does a gas furnace have an HSPF2 rating?
No. HSPF2 applies only to heat pumps. A gas furnace is rated by AFUE, which describes how much of the fuel becomes usable heat. If you are comparing a heat pump with a furnace, you compare installed cost and yearly operating cost instead of the two ratings directly.
Can I compare an old SEER number with a SEER2 number?
Not directly. The test procedures and calculations differ, and the newer procedure generally produces lower numbers for the same equipment. Ask for current SEER2 and HSPF2 values on every quote so each option is measured the same way.
Which rating matters more in Colorado Springs?
For a heat pump, HSPF2 and cold-weather performance deserve at least as much attention as SEER2, because the heating season is long and cold here. Cooling still matters for summer comfort, so look at both and at how the system handles low outdoor temperatures.
Sources
- Heat Pump Equipment Key Product Criteria, ENERGY STAR
- Energy Conservation Program: Test Procedures for Central Air Conditioners and Heat Pumps, U.S. Department of Energy
- Air Source Heat Pumps fact sheet, New York Clean Heat
- Understanding the New Performance Metrics for Unitary Air Conditioners and Heat Pumps, EPRI
- SEER2 and HSPF2 Conversions, RESNET
- Heat Pumps, United Power
- Purchasing Energy-Efficient Residential Air-Source Heat Pumps, U.S. Department of Energy
Note: the federal Energy Efficient Home Improvement Credit (Section 25C) ended for equipment installed after December 31, 2025, so it no longer applies to new HVAC installations. For the rebates still available to Colorado Springs homeowners, see our 2026 Colorado HVAC rebates guide.
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