Top 10 Most Energy Efficient ACs in 2021: Costs and Pros & Cons

Our HVAC pros have selected the 10 most energy efficient central air conditioners. The units are divided by performance: 4 variable capacity options and 3 each for two-stage and single-stage models. Our strategy is to give you the most efficient options based on the performance level you want, as will be clear in the model reviews.

This guide is focused on the standard split system air source central air conditioners.

Each model is reviewed with the total cost installed, unit features and benefits, pros and cons, and information on how to use the AC for top ROI.

Split System Air Conditioner Options

As you shop for central ACs, considerations will include:

Size/Capacity: Residential air conditioning units can range in size from 1.5 to 5.0 tons, which corresponds to 18,000 BTU to 60,000 BTU.

Efficiency: ACs start at 13 SEER, though the least efficient from most brands are now 14 or 15 SEER. Maximum efficiency increases every year and tops out at 26 SEER for 2021.

Important Notes:

SEER is Seasonal Energy Efficiency Ratio, a measurement of how effectively the unit uses electricity to move heat from inside to outside.

SEER ratings: Each model’s SEER rating is qualified with “Up to.” Why? Because the efficiency level drops slightly in larger models. For example, the Carrier Infinity 26 offers 26 SEER in the 2-ton and 3-ton sizes, but the 3.5-ton to 5-ton models range from 22.5 to 25 SEER.

Installed Cost: Expect to pay $4,500 to about $12,500 to have a central AC installed. This includes the outdoor condensing unit, a matching coil placed in or adjoining your furnace or air handler, new refrigerant lines and possibly a new thermostat.

Average Cost To Install Central AC Typical Range: $3,870 - $5,430
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Average Cost: Most homeowners pay between $6,000 and $9,500 for a 3-ton, 18 SEER air conditioner with a two-stage compressor.

Cost factors are straight-forward: The central air conditioning unit’s size, quality, efficiency, performance level and the complexity of installation are the major determinants of final cost.

The units in our Top Central AC list are manufactured by brands known for superior quality.

What is an Air Source Central Air Conditioner?

Let’s break down that question to find the answer:

Air source: The AC pulls heat from the air in your home and, here’s the key, releases it in the air outside.

While this is obvious, we mention it in distinction to a geothermal or ground-source air conditioner that releases the heat through piping beneath the ground or submerged in water.

As a result, air-source ACs are not as energy efficient as geothermal units. However…,

Central: This means it serves the whole house – or a large section of a very big house. The units in this list work in conjunction with an air handler, which in most homes is a gas furnace. Cooled and dehumidified air is pushed through supply ducts into each room or zone of the home. Return ductwork circulates warm, humid air back to the air handler to be “treated.”

Air conditioner: These units supply cooled and dehumidified air only. The refrigerant in the system absorbs heat indoors and carries it outside to be released. They do not have reversing valves like a heat pump, so cannot supply heat.

As noted, they DO require ductwork, unlike a ductless mini split central AC or heat pump.

Top 10 Most Efficient Central Air Conditioners in 2021

1-4 are Variable-capacity ACs: They have compressors that operate between 40% (25% on some models) and 100%. The “speed” of the compressor modulates very slightly up or down to maintain very even indoor temperatures. They are the most expensive, most efficient and remove the most water from humid indoor air.

5-7 are 2-stage models: These units are top-sellers for their balance of efficiency, climate control and reasonable cost. They are manufactured with compressors that run at 65% of their potential to maintain your home’s comfort level. When outdoor temperatures rise quickly or you turn down the thermostat, they shift to 100% capacity to catch up.

8-10 are Single-stage ACs: Their compressors operate at 100%. They are the most affordable and least efficient. In very humid weather, they might not remove as much moisture from the air as you would like.

Remember, the list is grouped 1-4/variable capacity, 5-7/two-stage and 8-10/single-stage, so the most efficient air conditioners top the list.

Identical Brands – Most of the units in our list have a “twin” from another brand. For example, the Carrier Infinity 26 and the Bryant Evolution Extreme 26 are identical in all but the cabinet and name plate.

So, if you don’t see your favorite brand in the 10 Most Efficient list, check the Identical Models entry at the end of each Review. It might be there. Below the Reviews, we list a who’s who in HVAC equipment manufacturers and the brands each makes.

  1. Lennox Signature Series SL28XCV Air Conditioner
  2. Carrier Infinity 26 Air Conditioner
  3. Lennox Signature Series XC25 Air Conditioner
  4. Daikin DX20VC Air Conditioner
  5. Lennox XC21 Air Conditioner
  6. Daikin DX18TC Air Conditioner
  7. York YXT 19 Air Conditioner
  8. Lennox Signature Series SL18XC1 Air Conditioner
  9. York YCG 17 Air Conditioner
  10. Lennox Elite Series EL16XC1 Air Conditioner

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Central Air Conditioning Cost in 2021 – Buyer’s Guide

Staying cool during the sweltering heat of summer takes power. A fan helps but doesn’t quite cut it. Portable air conditioners and window units are decent for a single room use.

For the whole house, you’ll want a central system that can maintain steady temperatures in multiple rooms. Central AC delivers on power, yet there are many units to select from in the current market. Our buyer’s guide will walk you through the primary considerations such as the appropriate models, installation costs, and other relevant factors to help you make the most informed decision.

Central Heating and Air Conditioning system outside the house
via Red Star Air

Cost

The national average cost to install a new split-system central AC is $5,500. This includes a new mid-range 17-21 SEER (2-stage) outdoor unit and evaporator coil (split system), professional (warrantied) installation, any required site assessments and building permits, and the workmanship warranty from the installer. It is assumed that most of the required ductwork is already in place, with only minor alterations or updates required to be made to the existing ductwork.

The numbers provided above translate to a licensed HVAC contractor installing the most feasible central unit with a minimum 17 SEER (2-stage) rating for your home. The installer’s expertise draws upon many factors, not the least of which is evaluating your current ductwork strengths and weaknesses, along with how well your home is insulated, and will therefore retain the cool energy in your home.

All else being equal, higher SEER efficiency AC units with 20-26 SEER (variable-capacity) ratings will cost more (between $5,500 and $6,500+ installed) than typical mid-range 17-21 SEER (2-stage) units (between $4,000 and $5,500 installed).

Average Cost To Install Central AC Typical Range: $3,870 - $5,430
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Wider Pricing Range (captures 80% of projects): Most homeowners spend between $4,000 and $8,500 for a full installation (replacement) of a split-system central air conditioner across the US. The total cost of a project depends on the brand and type of the AC unit (SEER and ERR ratings) being installed, project specifics (AC unit size in tons/BTUs, project complexity), and your home’s location (local real estate market dynamics).

Did you know? Central Air Conditioners come in two types; a split-system unit or a packaged unit. If your home already has a heating furnace, but no AC, then the split-system central AC unit is the most economical option to install.

Central AC Unit Costs
Typical “per Unit” price list, with models organized by Climate requirements

Did you know? Energy Star has a list of Most-Efficient Central Air Conditioners and Air Source Heat Pumps. To have an Energy Star rated unit appear on that list, a minimum rating of 18 SEER and ERR of 13 is the table-stakes.

Modern Central AC units are 20% to 40% more efficient than Central ACs from 10 years ago. So, if your home happens to have an older central AC unit, then getting a modern Energy Star rated central AC might prove to be a smart and economically-sound decision, especially if your current AC is not performing well and/or needs an expensive repair.

central AC average installation costs breakdown
Professional Installation Costs breakdown (not including the cost of the AC unit itself)

via US Veterans Home Services Inc.

Did you know? When added to an existing forced-air heating system with the already existing ductwork already in place, a new central air unit for a typical 2,000 sq. ft. home will cost between $4,000 and $6,500 to install.

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Top 10 Air Heat Pumps: Costs, Pros & Cons, ROI – Buying Guide

We’ve selected the 10 best air heat pumps in three performance categories to give you the information needed to make your buying decision.

This air source heat pump buying guide includes costs for each model, features, pros and cons, and the use that gives the best return on investment for each.

Air Heat Pump Options

Size and efficiency vary significantly, producing a wide cost range as a result.

Size or capacity to move heat: 1.5 tons to 5.0 tons, or 18,000 to 60,000 BTUs per hour.

Efficiency: 13 SEER cooling efficiency and 8.0 HSPF heating efficiency to 24 SEER and 13 HSPF. The higher the rating, the more efficient the unit.

Installed cost range: $4,500 to $13,500

Average cost: A 3-ton, 17 SEER two-stage central heat pump is right about average, and the installed cost is $7,500 to $10,500 based on brand and installation complexities. Expect to pay about $9,000 for a complete system with the capability, especially if you choose one of the top heat pumps available.

There are cheaper brands like Goodman and Payne, but you might not get the long-term quality and performance you’re here to find.

Cost factors are explored below. They’ll allow you to narrow down your potential heat pump installation cost based on the units you’re considering.

What is an Air Source Heat Pump?

Simply put, an air heat pump, or air source heat exchange pump moves heat from one place to another. It does not create heat. A heat pump collects heat from the outside air when heating your home. It dumps heat from your house into outside air when air conditioning your home. That seems obvious – but the contrast is to a ground source heat pump, also called a geothermal heat pump.

Cold Climate Air Source Heat Pumps Can Provide Heat in Temperatures as low as -13 Fahrenheit

Ground source heat pumps collect and dump heat underground, or sometimes in a body of water, where year-round temperatures are consistent. This makes geothermal heat pumps more efficient – it is easier to collect heat for warming your home in ground that is 55 to 60 degrees than from air that is much colder.

Likewise, dumping heat into ground or water in that temperature range is easier than dispersing it into air that is 80 to 100+ degrees. However, geothermal heat pumps cost much more and might not be a cost-effective choice for your situation.

When to Choose an Air Source Heat Pump

They are an excellent fit for most climates, though they make less sense for locations where winters are very cold.

When winter temperatures drop into the 30s or lower, auxiliary electric heat strips in the air handler assist with heating.

However, electric heat is the most expensive type, so overall efficiency is lost, and energy costs rise when the heat strips are used a lot. For this reason, heat pumps are not best sellers in the colder, northern regions of North America.

Dual fuel systems with a heat pump and gas furnace are an option in very cold climates. They’re explained in the Top Air Source Heat Pump Reviews below.

Top 10 Air Heat Pumps

We’ve selected 3 single-stage, 4 two-stage and 3 variable capacity heat pumps for the list. They’re sorted accordingly below where you will find full heat pump reviews for these top 10 models including cost, pros and cons, ROI based on your climate and more details.

  1. Trane XL16i Heat Pump
  2. Carrier 25HCC5 Performance 15 Heat Pump
  3. Ducane 4HP15L Heat Pump
  4. Lennox XP21 Heat Pump
  5. Armstrong 4SHP16LS Heat Pump
  6. Carrier 25HNB6 Infinity 16 Heat Pump
  7. Rheem Classic Series RP16 Heat Pump
  8. Carrier 25VNA4 Infinity 24 Heat Pump
  9. Lennox XP25 Heat Pump
  10. Trane XV20i Variable Speed Heat Pump

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