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
See costs in your area

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

Read more

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
See costs in your area

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.

Read more

Top 10 Best Central Air Conditioners in 2021: Costs by AC Unit

Central AC Unit Costs

There are plenty of cheap central air conditioners, but there is more to value than low price.

On the other end of the spectrum are high-priced, high-performance ACs with variable capacity cooling and communication technology. They’re not what anyone would call a value choice either.

The sweet spot in the middle is where quality and reasonable cost meet to provide good value for the money. You’ve got a good selection of central air conditioners that are considered an excellent value.

Climate must be considered, too, because a value air conditioner in Jackson, Mississippi is not the same as a value AC in Jackson, Minnesota. We’ll explain why.

via Hamilton Home Comfort

Covering all climates, below are the top 10 Central AC options:

1. Day & Night Performance 17 N4A7
2. Rheem Classic Series RA17
3. York LX YCG
4. Goodman GSXC18
5. Day & Night Performance 16 N4A6
6. Rheem Classic Series RA16
7. Goodman GSXC16
8. Rheem Classic Series RA14
9. Day & Night Performance 14 N4A5
10. Goodman GSX14

Average Cost To Install Central AC Typical Range: $3,870 - $5,430
See costs in your area

Read more