10 Common AC Mistakes Brooklyn Homeowners Make (And How to Avoid Them)

When summer hits in Brooklyn, your air conditioner becomes your best friend. But if you’re like most homeowners, you might be making a few mistakes that are causing your system to work harder than it should—or worse, setting yourself up for an unexpected breakdown during a heatwave.

Here are 10 of the most common AC mistakes we see at Petri Plumbing, Heating, Cooling & Drain Cleaning in Brooklyn homes (and how to avoid them so your system runs stronger, longer, and more efficiently).

1. Skipping Regular AC Maintenance

This is the #1 reason we get emergency repair calls mid-summer. AC systems, just like cars, need regular tune-ups. A yearly AC maintenance appointment helps catch small issues before they become expensive problems.

Think of it as a wellness check for your home comfort system. Without it, even a newer unit can lose efficiency or break down prematurely.

2. Ignoring Dirty Air Filters

A clogged air filter restricts airflow, making your system work harder and reducing the air quality inside your home. It’s also one of the easiest problems to avoid.

Check your filter every 30 days in summer. Replace or clean it regularly—especially if you have pets, allergies, or live on a dusty block.

3. Setting the Thermostat Too Low

Cranking your thermostat down to 60°F won’t cool your home faster—it just forces your AC to run longer, wasting energy and increasing wear and tear.

Instead, aim for 72–75°F during the day and use ceiling fans to circulate air. Your unit will work smarter, not harder.

4. Closing Off Vents in Unused Rooms

It might seem like a good idea to close vents in rooms you’re not using—but doing so can throw off your system’s balance and cause pressure issues in the ductwork.

Let your system do what it was designed to do: cool the whole space evenly.

5. Putting Off AC Repairs

Strange sounds, weak airflow, or unexpected spikes in your energy bill are signs something isn’t right. Waiting too long can turn a small issue into a big one.

If you suspect a problem, call for AC repair in Brooklyn, NY as soon as possible. Fast action can save you money and keep your summer stress-free.

6. Installing the Wrong Size Unit

Whether it’s a window unit or a central system, size matters. A unit that’s too small won’t cool your home effectively, and one that’s too large will short-cycle—turning on and off too often, which wears it out faster.

If you’re considering a new system, always get a professional load calculation before moving forward with AC installation in Brooklyn. Your square footage, insulation, and window placement all play a role in picking the right size.

7. Running the System Nonstop

Your AC should cycle on and off periodically to maintain the temperature. If it’s constantly running, that’s not normal—and it’s probably costing you.

It could mean your thermostat is in a bad location, your filter is clogged, or your system is due for service. A skilled air conditioning technician near you can help identify the issue and get things back on track.

8. Forgetting About Ductless Options

Many Brooklyn brownstones and apartments can’t accommodate traditional ductwork, but that doesn’t mean you’re stuck with window units. Ductless mini-split systems are sleek, efficient, and ideal for historic homes or awkward layouts.

If you’ve ruled out central air in the past, it might be worth revisiting your options. Modern systems are more flexible than ever—and often more affordable in the long run.

9. Blocking Airflow with Furniture or Curtains

You’d be surprised how many cooling issues come down to a sofa or dresser placed in front of an air vent. When airflow is blocked, rooms can feel warmer and your system works harder to compensate.

Make sure vents and returns are clear of obstructions so air can circulate freely.

10. Delaying AC Replacement Too Long

Even with perfect maintenance, air conditioners don’t last forever. If your unit is 10–15 years old, needs frequent repairs, or just isn’t cooling your home like it used to, it might be time for an air conditioning replacement in Brooklyn, NY.

A newer system will be quieter, more efficient, and better at handling NYC’s hot, humid summers. Plus, federal tax credits and rebates might be available to help offset the cost.

Let’s Get Your AC Running Right

Whether you’re dealing with uneven cooling, rising energy bills, or a system that just feels off, you’re not alone—and you’re not stuck.

At Petri Plumbing, we’ve been helping Brooklyn homeowners keep cool for over 100 years. From smart upgrades to reliable AC services in Brooklyn, NY, we’re here to make your summer easy and breezy.

Don’t wait until the hottest day of the year to act. Contact us today to schedule your AC maintenance, repair, or installation.

Learn More About Brooklyn AC Repair, Replacement & More

Check out our blog posts below for some helpful info, expert tips and more!

• 5 Ways To Make Your AC Work Smarter (and Save Money) in Brooklyn
• Who’s Got the Funk? (Is it Your AC?)
• When to Repair vs. Replace Your Air Conditioner: A Brooklyn Homeowner’s Dilemma
• Window Units vs. Central Air: What’s Best for Brooklyn Brownstones?