Why Air Conditioner Size Matters (And How to Get It Right for Your Ottawa Home) By Clockwork HVAC | Ottawa’s Trusted Cooling Experts

Apr 12

When you're shopping for a new air conditioner, it's easy to assume that bigger means better—especially in Ottawa’s hot and humid summers. But when it comes to cooling your home, air conditioner size matters a lot—and installing the wrong size system can lead to higher bills, uneven comfort, and even long-term damage to your HVAC equipment.

At Clockwork HVAC, we help homeowners across Ottawa find the right-size AC based on their home, lifestyle, and budget. Let’s break down why sizing matters and how you can avoid the most common mistakes.

📏 What Does “Air Conditioner Size” Actually Mean?

Air conditioners are sized by their cooling capacity, measured in tons or BTUs (British Thermal Units). Common residential units range from 1.5 to 5 tons, with one ton equal to 12,000 BTUs/hour of cooling power.

But AC sizing isn’t just about square footage. It also depends on:

Home layout and insulation
Ceiling height
Number of windows
Sun exposure
Ductwork condition
Number of people in the home

A proper load calculation (which we perform at Clockwork HVAC) takes all these factors into account to ensure your system is perfectly matched to your space.

🚫 The Problem with an Oversized Air Conditioner

Bigger isn’t better. If your air conditioner is too large for your home:

❌ It will short cycle, turning on and off too frequently
❌ It won’t properly remove humidity
❌ You’ll experience uneven temperatures
❌ It uses more energy than necessary
❌ It wears out faster, reducing lifespan

An oversized system might cool your home quickly, but it won’t dehumidify the air well—leading to that sticky, clammy feeling we all try to avoid in the summer.

🌀 The Risks of an Undersized Air Conditioner

On the flip side, an AC that’s too small will:

🔁 Run constantly without ever fully cooling your space
💸 Drive up your electricity bill
😓 Leave your home feeling warm and uncomfortable on hot days
🛠️ Experience faster wear and tear trying to keep up with demand

An undersized system works overtime—and still can’t deliver the comfort you need.

⚖️ The Goldilocks Zone: Why Proper Sizing Is Key

When your air conditioner is just the right size, it:

✅ Keeps your home consistently cool
✅ Removes humidity effectively
✅ Runs efficiently, reducing energy costs
✅ Lasts longer with fewer repairs
✅ Improves air quality and overall comfort

That’s why Clockwork HVAC uses precise Manual J load calculations to size every system we install—no guessing, no upselling, just the right fit for your home.

🏡 Real-World Example: A Mismatch in Ottawa

We recently helped a homeowner in Nepean who had a 3-ton AC installed in a modest 1,200 sq ft bungalow. It short-cycled constantly, caused high humidity, and led to mold issues in the basement.

We replaced it with a properly sized 2-ton unit, and within a week:

The home cooled more evenly
Energy usage dropped
The indoor air felt drier and more comfortable

Proper sizing = problem solved.

🤔 Not Sure If Your AC Is the Right Size?

Here are a few signs that your current air conditioner might be improperly sized:

Your home is cool in some rooms, hot in others
The system turns on and off constantly
It runs all day and still struggles to cool
High energy bills during the summer
Poor humidity control

If any of these sound familiar, it’s worth having a professional assessment.

Why Choose Clockwork HVAC for Your Next AC?

At Clockwork HVAC, we:

Perform accurate load calculations
Customize system recommendations
Install high-efficiency, ENERGY STAR® ACs
Offer expert service with honest advice
Provide help with rebates and financing

Whether you’re replacing an old unit or upgrading for the first time, we make sure your system is built for comfort, built to last.

Book Your AC Consultation Today

Don’t let the wrong AC size leave you sweating this summer.
📞 Call Clockwork HVAC or 💻 book a free in-home assessment today.
We’ll help you find the perfect fit—no more, no less.