HVAC · Service

AC installation, priced honestly

The top-ranked page for this search will not tell you what air conditioning costs. We will — and we will tell you why the crew installing it matters more than the brand on the box.

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In short

What is ac installation?

AC installation means fitting a central air conditioning system: an outdoor condenser, an indoor evaporator coil sitting on your furnace or air handler, refrigerant lines between them, and the electrical and control wiring that ties it together. A straightforward install runs one day. The two things that decide whether you are happy with it five years from now are correct sizing and installation quality — not the brand.

Triggers

Signs you need ac installation

Your current AC is 12–15 years old and this is the second summer you have paid for a repair
The system still uses R-22 refrigerant — servicing it is now expensive enough that repairs stop making sense
Some rooms cool and some never do, and no amount of thermostat fiddling changes it
The unit runs constantly on hot afternoons and still cannot hold the temperature you set
It cools, but the air feels clammy — a sign the system is oversized and short-cycling before it can dehumidify
You are finishing a basement, attic or addition and the existing system was never sized to cover it
You have never had central air, and window units are no longer keeping up

Seeing something not on this list? Browse hvac problems by symptom →

The job

How ac installation actually works

Load calculation and equipment sizing

A Manual J calculation works out the actual cooling load of your house — insulation levels, window area and orientation, ceiling height, air leakage, how many people live there. That number, not your square footage, sets the tonnage.

Watch for: The phrase "we'll put in the same size you have now". Your existing unit may have been wrong from the day it went in, and a lot of homes have had the same wrong size replaced three times. Ask to see the calculation.
Efficiency tier and the SEER2 decision

SEER2 is the current efficiency rating. Higher tiers cost more up front and cut running cost — the payback depends almost entirely on how many cooling hours your climate actually has. In Phoenix a high tier pays back quickly. In Seattle it may never.

Watch for: An efficiency upsell presented without a payback calculation for your climate and your electricity rate. Ask what the annual saving is in dollars, then divide it into the price difference yourself.
Matching the indoor coil to the outdoor unit

The outdoor condenser and the indoor evaporator coil are engineered as a pair. Rated efficiency assumes a matched set. Bolting a new condenser onto an old coil is cheaper on the quote and quietly costs you capacity and efficiency for the life of the system.

Watch for: A quote that replaces the outdoor unit only. Sometimes that is legitimate — usually it is a way to win on price. Get it explained in writing, including what the resulting rated efficiency actually is.
Removal, refrigerant recovery and site prep

The old condenser is disconnected and its refrigerant recovered — legally required, not a courtesy. The new pad is levelled with clearance on all sides for airflow, and clear of anywhere a dryer vent or a gutter downspout discharges.

Watch for: A unit crammed against a fence or wedged under a deck. Restricted airflow raises head pressure, which raises your bill and shortens compressor life. Manufacturers publish minimum clearances; they are not suggestions.
Line set, brazing and evacuation

Refrigerant lines are run, brazed with dry nitrogen flowing through them, then pulled into a deep vacuum to remove air and moisture before the charge is released. This stage is invisible once the panels go on, which is exactly why it gets skipped.

Watch for: No vacuum pump and micron gauge on site. A quick "purge" instead of a proper evacuation leaves moisture in the system, which forms acid and kills the compressor — typically three to six years later, long after the crew has gone.
Electrical, condensate and controls

The condenser needs a correctly sized circuit and a service disconnect within sight of the unit. Indoors, the coil needs a condensate drain that actually drains, usually with a secondary pan or a float switch so a blocked line does not end up in your ceiling.

Watch for: No float switch on an attic or above-ceiling coil. It is a small part, and it is the difference between a clogged drain being a nuisance and being a drywall claim.
Charging and commissioning

The charge is set by superheat or subcooling — measured, not estimated by how the line feels. Airflow across the coil is measured, static pressure is checked, and the thermostat is configured for the equipment's staging.

Watch for: No commissioning numbers handed over at the end. Ask for measured subcooling, superheat, static pressure and delta-T on the invoice. A crew that measures will write them down; a crew that guesses will tell you it "feels good".
Permit, inspection and warranty registration

Most jurisdictions require a permit for AC replacement, and the inspection is a free second opinion on your installer's work. Manufacturer parts warranties usually need registering within a set window after installation.

Watch for: An installer who suggests skipping the permit to save money. That is your protection they are saving on, and unpermitted work can surface awkwardly when you sell the house.

Money

What does ac installation cost?

A new central air conditioning system with installation typically lands between $4,000 and $9,000 for a normal residential replacement. Tonnage, efficiency tier, whether the indoor coil is replaced too, and any electrical or ductwork remediation are what move you within that range.

See the full ac installation cost guide — by material, size and region →

Size your system with the BTU calculator → A sanity check on the tonnage you are quoted — not a substitute for Manual J.

Straight answer

When ac installation is the wrong call

Everyone else ranking for this is paid when you say yes. Here's when you shouldn't.

Your ducts leak badly and you are not fixing them. A typical house loses a meaningful share of conditioned air through duct leakage. Buying a bigger, more efficient unit to push more cold air into your attic is paying twice for the same problem. Seal first, then size.
Your furnace is a year or two from replacement. The indoor coil sits on the furnace. Installing AC now and the furnace next year means paying twice for the same access and losing the matched-system efficiency. Either do both together or wait.
The only real problem is one hot room. Replacing a working system will not fix a room the ducts never properly reached. That is a distribution problem — a duct fix, a damper balance, or a single mini-split head, all of which cost far less.
The existing unit is under ten years old and the fault is a capacitor or a contactor. These are inexpensive, common parts. Being quoted a full replacement for a system that fails to start is worth a second opinion before you sign anything.
You are in a mild climate and running the AC a few weeks a year. The efficiency argument for a whole central system weakens fast when the annual runtime is short. Two well-placed mini-split heads may serve you better for less.
You are selling within a year. Air conditioning helps a listing, but a new system rarely returns its full cost in sale price. If the current one works, disclose its age and let the buyer decide.

Your options

Types of ac installation

Central air conditioner

Cooling only, paired with your existing furnace or air handler.

Heat pump instead

Same box, but it heats as well as cools. Worth comparing before you buy cooling alone.

Ductless mini split

For homes with no ducts, or rooms the ducts never reached.

Mini split vs central air

The comparison, side by side.

Compare hvac options side by side →

Before you sign

What to check when hiring for ac installation

Can I see the Manual J load calculation for my house?

The single highest-value question here. Sizing from square footage or from the old unit is how homes end up with clammy air and short-cycling equipment.
Does this quote include a matching indoor coil, or just the condenser?

The most common reason one quote is thousands cheaper than another. It is not always wrong, but you need to know which one you are comparing.
What SEER2 rating does the installed pair achieve, not the outdoor unit alone?

A high-efficiency condenser on a mismatched coil does not deliver its rated number. The AHRI-matched rating is the honest figure.
Will you evacuate the line set with a vacuum pump and a micron gauge?

The step that determines whether the compressor lives to fifteen years. Asking it signals you will notice if it is skipped.
Are you pulling a permit, and is it in the price?

The municipal inspection is free quality control on your installer. An offer to skip it is an offer to remove your safety net.
What are the labour warranty terms, separate from the parts warranty?

Manufacturer parts warranties are long. Labour warranties are the installer's own, are usually much shorter, and are where the real cost sits when something fails.
Will you give me the commissioning readings in writing?

Subcooling, superheat, static pressure, delta-T. These are your evidence if you ever need to argue a warranty claim, and your proof the job was finished properly.

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Local pros

AC Installation near you

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Related work

Often done at the same time

HVAC Replacement

Doing heating and cooling together

Heat Pump Installation

The one-system alternative

AC Repair

When it is not replacement time yet

Ductwork Installation

If the ducts are the real problem

All hvac services →

Go deeper

Guides & terms

Guides

HVAC Sizing Guide

All hvac guides →

Terms on this page

SEER2

Full hvac glossary →

FAQ

AC Installation — questions people ask

Still have a question? Talk to our team →

How long does AC installation take?

A like-for-like replacement is typically a single day, roughly six to ten hours with a two-person crew. Add time if the indoor coil is awkward to access, if a new line set has to be routed through finished walls, or if the electrical circuit needs upgrading. First-time installs in a house that has never had central air take longer, because the ductwork and drainage do not exist yet.

What size air conditioner do I need?

Only a Manual J load calculation answers that honestly. It accounts for insulation, window area and orientation, air sealing and occupancy — not just floor area. Resist the instinct that bigger is safer: an oversized unit cools the air quickly, shuts off before it has removed the humidity, and leaves the house cold and damp. Short cycling also wears the compressor out early.

Does the brand of air conditioner matter?

Far less than most marketing suggests. The major manufacturers build broadly comparable equipment at comparable tiers, and several brands share parent companies and components. What varies enormously is installation: sizing, line-set evacuation, charge accuracy and airflow. A mid-tier unit installed properly will outlast and outperform a premium unit installed badly, every time. Choose the contractor first, then the equipment.

Can I just replace the outside unit?

Sometimes, but understand what you are buying. The condenser and the indoor evaporator coil are rated as a matched pair, and pairing new with old usually means you do not get the efficiency you paid for, and can create warranty ambiguity. If a contractor proposes it, ask what the resulting matched rating is and why it makes sense in your case — not just what it saves today.

Do I need a permit to install air conditioning?

In most US jurisdictions, yes — AC replacement is permitted work, and the electrical connection often is too. Your contractor normally pulls it. The inspection that follows is a second qualified set of eyes on the installation at no extra cost to you, which is a good deal. Unpermitted mechanical work also has a habit of resurfacing during a home sale.

Is a heat pump worth considering instead of AC?

It is worth at least pricing. A heat pump is mechanically an air conditioner that can also run in reverse to heat, so the cooling performance is comparable and the installation is similar. If your furnace is also aging, or you heat with electric resistance, propane or oil, the comparison often favours the heat pump. If you have cheap natural gas and a healthy furnace, it often does not.