Central AC Installation on Long Island

You’re done with window units. They’re loud, they block light, and they only cool one room. Installing central air for the first time feels like a big decision, and it is, but it’s also one that changes how you live through summer. AJ Services has installed hundreds of central air systems across Nassau County and eastern Suffolk. We handle the whole project: equipment selection, ductwork design, permits, installation, and getting your thermostat dialed in perfectly.

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Why Central AC Makes Sense on Long Island

Long Island summers are hot and humid. July and August average 70 to 75 percent humidity, which means your AC has to do two jobs: cool the air and remove moisture. If your home isn’t properly sized or the system shuts off too quickly, you’ll end up feeling clammy even when the thermostat reads 72 degrees. That’s why proper sizing and good ductwork matter so much.

PSEG Long Island electricity rates are among the highest in the country—often 25 to 30 cents per kilowatt-hour compared to the national average of 12 to 15 cents. That means the efficiency of your AC system directly impacts your summer bills. A modern high-SEER system costs more upfront, but you’ll see the payback in lower energy costs, especially in a hot summer.

If your home is an older cape, ranch, or colonial without ductwork, you’re not out of luck. Many homes need ductwork installed, and that’s part of the job we do. Some homes are better served by high-velocity systems or mini splits, which we also specialize in. During a consultation, we’ll talk through what works best for your house.

Our Central AC Installation Process

Here’s what happens from start to finish. First, we do a load calculation specific to your home. We measure your square footage, check your insulation, windows, and sun exposure, and talk about how you use your home. This tells us exactly what size system you need—not too big, not too small, just right for keeping you comfortable and removing humidity.

Next, we design your ductwork. If your home doesn’t have ducts already, we figure out the best way to run them—through the attic, basement, or walls—without tearing up your whole house. If you do have existing ductwork, we inspect it and make sure it’s sized and sealed properly. We pull all the Nassau County permits so you don’t have to chase paperwork.

On installation day, we bring in the equipment, set up the outdoor condenser unit, install the indoor air handler, connect the refrigerant lines, run the ductwork, and install your new thermostat. We test everything, verify the airflow is balanced throughout the house, and show you how to use your new system. The whole job typically takes 1 to 3 days depending on how much ductwork is needed.

What’s Included in Central AC Installation

  • Load calculation and system sizing—we don’t guess.
  • Equipment—indoor air handler and outdoor condenser unit.
  • Ductwork design and installation (if needed) or inspection and sealing of existing ducts.
  • Refrigerant lines and electrical connections.
  • New thermostat—we recommend a WiFi-enabled smart thermostat for better control and efficiency.
  • Nassau County permits and inspections.
  • Test, balance, and commissioning of the system.
  • Cleanup and haul-away of old equipment if you’re replacing an existing system.

Is Central AC Right for Your Home?

  • You rely on window AC units and want whole-home cooling.
  • You’re planning a renovation or upgrade and this is a good time to add HVAC.
  • Your home feels inconsistently comfortable—some rooms are hot, some are cold.
  • You’re adding rooms, finishing a basement, or expanding the conditioned space.
  • You want to increase your home’s resale value and buyer appeal.
  • You’re tired of managing multiple window units and want one system you can control from one thermostat.

Why Long Island Homeowners Trust AJ Services

We’re not a big national franchise—we’re a family-owned company that’s been keeping Long Island homes cool since 2000. We understand the homes here. We know which neighborhoods have older houses with tricky ductwork, which areas struggle with salty air near the south shore, and what SEER ratings make sense given PSEG’s high rates. We pull our own permits, so you get a professional job that passes inspection the first time.

Every technician is licensed and trained. We stand behind our work with a warranty and we’re here for service calls after the job is done. And because we’re 24/7, if you have questions in the middle of summer, you can reach us.

Frequently Asked Questions

How long does central AC installation take?

If your home already has ductwork and we’re just installing new equipment, one day. If we need to run ductwork, plan for 2 to 3 days. We’ll give you a detailed timeline during the consultation.

Do I need permits to install central air on Long Island, and do you handle them?

Yes, Nassau County requires permits for new AC systems. Yes, we handle all the permits. It’s part of the job—no extra cost to you, just one less thing to worry about.

How do you size an AC system?

We do a load calculation. We measure your home’s square footage, check insulation levels, count windows, and ask about your daily routine and cooling preferences. All of that feeds into a calculation that tells us the exact tonnage and BTU output your home needs.

My house is older and doesn’t have ductwork—can I still get central air?

Yes. We can install ductwork in most homes, even old ones. If running traditional ductwork isn’t practical, we can install a high-velocity system or a mini split system instead.

What SEER rating should I choose?

SEER (Seasonal Energy Efficiency Ratio) measures efficiency. Higher SEER means lower operating costs. On Long Island where power is expensive, we usually recommend at least a 16 SEER system. It costs more upfront but pays for itself in energy savings over time. We’ll review options and payback at your estimate.

How much does central AC installation cost on Long Island?

It depends on your home’s size, whether ductwork is needed, the SEER rating you choose, and local market costs. A complete install can range widely. We provide a detailed, free estimate so you know exactly what you’re paying for.

Ready to stop sweating through summer and get central air installed? Call AJ Services at (516) 807-8700 for a free consultation and estimate. We serve Nassau County and eastern Suffolk. Licensed, insured, family-owned—trusted on Long Island for 20+ years.

Service Areas

Great Neck
Lake Success
Floral Park
Elmont
Valley Stream
Hewlett
Woodmere
Lawrence
Cedarhurst
Inwood
Lynbrook
Malverne
Franklin Square
New Hyde Park
West Hempstead
Hempstead
Garden City
Garden City Park
Mineola
Manhasset
Roslyn
Roslyn Heights
East Hills
Old Westbury
Westbury
Uniondale
Roosevelt
Baldwin
Freeport
Oceanside
East Rockaway
Island Park
Atlantic Beach
Long Beach
Lido Beach
Point Lookout
Port Washington
Sands Point
Sea Cliff
Glen Cove
Glen Head
Locust Valley
Brookville
Old Brookville
Muttontown
Syosset
Oyster Bay
Laurel Hollow
Bayville
Jericho
Hicksville
East Meadow
Levittown
Plainedge
Bethpage
Bellmore
Bellmore
North Bellmore
Merrick
Seaford
Massapequa
Amityville
Farmingdale
Old Bethpage
Plainview
Woodbury
Melville
Dix Hills
Lindenhurst
West Babylon
Babylon
North Babylon
Deer Park
Wheatley Heights
Huntington
Huntington Station
Cold Spring Harbor
Lloyd Harbor
Centerport
Greenlawn
East Northport
West Islip
Islip
East Islip
Bay Shore
Brightwaters
Brentwood
Commack
Kings Park
Smithtown
Hauppauge
Great River
Oakdale
St. James
Nesconset
Nissequogue
Lake Grove
Ronkonkoma
Holbrook
Islandia
Bohemia
Sayville
Bayport
Blue Point
Patchogue
Holtsville
Farmingville
Medford
Coram
Stony Brook
Setauket
Port Jefferson
Port Jefferson Station