10 Common Mistakes When Buying a New Air Conditioner

Choosing a new air conditioner isn’t something most of us do often. Many homeowners only replace their cooling system every 10–12 years, so it’s easy to feel unsure about what to look for or how to compare your options. And because an air conditioner is a major home investment, it’s important to make decisions that will keep your home comfortable and your long-term costs reasonable.

Across Canada, especially in Ontario where summers can be humid, homeowners commonly run into the same pitfalls when replacing their AC. Understanding these mistakes beforehand can help you avoid unnecessary expenses, performance issues, and future headaches.

Here are 10 common mistakes to avoid when buying a new air conditioner, along with practical tips to help you make a confident, informed choice.

11. Choosing the Wrong Size

22. Forgetting to Factor in the Full Cost

33. Ignoring Energy Efficiency Ratings

44. Not Comparing Multiple Quotes

55. Choosing the Cheapest Option Instead of the Best Value

66. Not Doing Enough Research Before Buying

77. Overlooking Noise Levels

88. Hiring Someone Who Isn’t Fully Licensed

99. Forgetting to Check for Rebates

1010. Getting Only One Estimate for Installation

11Staying Comfortable — Putting These AC Buying Tips Into Practice

12Need help choosing the right air conditioner?

1. Choosing the Wrong Size

One of the most frequent — and most costly — mistakes is selecting an AC unit that isn’t the right size for your home. Whether the system is too large or too small, an improperly sized air conditioner can lead to higher energy bills, more maintenance needs, inconsistent cooling, and a shorter lifespan.

A unit that’s bigger than necessary will cool the home rapidly but shut off too quickly. This constant stopping and starting, known as short cycling, wastes electricity, stresses components, and often leads to humidity problems. On the other hand, an undersized system will struggle to keep up on warm days, running continuously and wearing out sooner than it should.

To ensure your air conditioner is sized correctly, the installer should consider your home’s square footage, layout, insulation quality, window placement, and sun exposure — not just a rough estimate. A proper load calculation provides the most accurate assessment.

If you’re unsure where to begin, try using an AC sizing guide or calculator to get an early estimate based on your home’s dimensions before speaking with a contractor.

2. Forgetting to Factor in the Full Cost

It’s easy to look at the price of the unit itself and assume that’s the total investment. In reality, the cost of replacing an air conditioner includes installation, potential electrical upgrades, new refrigerant lines (if needed), and ongoing maintenance.

Prices in Ontario and across Canada can vary depending on home size, efficiency ratings, and the type of system you choose. While a quote from a certified contractor will give you the most accurate number, using an online AC cost calculator can help you determine a reasonable ballpark figure so you know what to expect.

Understanding the full financial picture early on helps prevent surprises and makes it easier to compare estimates with confidence.

3. Ignoring Energy Efficiency Ratings

Every new air conditioner sold in Canada comes with a SEER (Seasonal Energy Efficiency Ratio) rating, which tells you how efficiently the system uses electricity. The higher the SEER rating, the less energy the AC needs to cool your home.

Although higher-efficiency models tend to cost more upfront, they can significantly reduce monthly hydro bills — especially in provinces like Ontario where summer cooling demand is high.

For most Canadian households, a SEER rating between 16 and 18 often provides the best balance between efficiency and cost. Ultra-high-efficiency units are available, but they may not always offer meaningful savings compared to the price.

If lowering long-term energy use is a priority, choosing a more efficient model can pay off for many years.

4. Not Comparing Multiple Quotes

When a cooling system fails, it can be tempting to go with the first estimate you receive. But taking the time to compare your options can save you money and help you find better service agreements.

Request at least three written quotes from licensed HVAC companies. When reviewing each estimate, look beyond the total price. Compare:

Warranty details
Efficiency ratings
Installation requirements
Expected timelines
What’s included and what may cost extra

Having multiple estimates also gives you a clearer picture of typical pricing in your area and helps you determine which company provides the best overall value — not just the lowest number.

5. Choosing the Cheapest Option Instead of the Best Value

It’s natural to gravitate toward the lowest price, especially when replacing a system unexpectedly. However, the least expensive unit may end up costing more over time through higher energy bills, more frequent repairs, or a shorter lifespan.

Take time to research how different models perform in real Canadian homes. Customer reviews and expert comparisons can highlight how well a system holds up over years of regular use. Components like the compressor type, build quality, and warranty coverage all affect long-term costs.

Often, spending a little more upfront results in a quieter system, fewer service calls, and lower hydro bills — savings that can add up significantly over the life of your air conditioner.

6. Not Doing Enough Research Before Buying

Because AC replacements don’t happen often, most homeowners aren’t familiar with modern cooling technologies, efficiency differences, or the impact of proper installation. Taking time to learn the basics can prevent costly mistakes.

A bit of research goes a long way. Read up on features like:

Single-stage vs. two-stage compressors
Variable-speed fans
Noise levels
Durability ratings
SEER improvements over older models

You don’t need to become an HVAC expert — just understanding the main terms will help you ask the right questions and feel more confident when comparing systems.

Doing your homework also ensures you end up with a system suited to your home rather than relying solely on sales recommendations.

7. Overlooking Noise Levels

Some air conditioners operate more quietly than others. If your outdoor unit sits near a bedroom window, backyard patio, or neighbouring property, noise levels can make a noticeable difference in comfort.

Air conditioners list sound ratings, often measured in decibels. In Canada, many homeowners prefer outdoor units that operate around 7.6 bels (or lower) for quieter performance.

A system that cools efficiently without generating unnecessary noise creates a more pleasant environment — both inside and outside your home. If you’re sensitive to sound, make this a key part of your comparison.

8. Hiring Someone Who Isn’t Fully Licensed

Buying a good air conditioner is only half the equation — installation quality has a huge impact on performance, efficiency, and lifespan. Poor installation can lead to refrigerant leaks, reduced cooling capacity, higher hydro bills, and even warranty denial.

Always choose a licensed HVAC company with qualified technicians who follow Canadian safety codes and manufacturer guidelines. A certified installer will:

Confirm correct system sizing
Ensure refrigerant levels and airflow are properly calibrated
Test the system for efficiency and safety
Protect your warranty

Even if you’re handy, DIY installations or hiring unlicensed labour can end up costing far more in repairs and potential system damage. Professional installation is one of the most worthwhile investments in the entire process.

If you need help getting started, you can compare quotes from certified contractors in your region to find a reliable installer.

9. Forgetting to Check for Rebates

Rebates can make high-efficiency air conditioners much more affordable. Many homeowners aren’t aware of the incentives available through:

Provincial and federal programs
Local utilities
Energy-efficiency organizations
Manufacturers
Financial institutions

Some rebates require a pre-approval before installation, so it’s smart to look into them early in the process. Rebates can reduce upfront costs and may even make it possible to upgrade to a more efficient model that saves more energy long term.

Before you commit to a purchase, take a moment to review current AC rebates in your area so you don’t miss out on potential savings.

10. Getting Only One Estimate for Installation

Just like comparing equipment options, comparing installation estimates is essential. Even if you’ve already chosen the air conditioner you want, different HVAC companies may offer different pricing, workmanship guarantees, and service packages.

Request at least three installation quotes from licensed professionals. Each estimate should include:

Labour costs
Materials
Timeline
Warranty information
Any additional recommended upgrades
A written project summary

Seeing multiple offers helps you understand what’s standard and what’s unusual, which allows you to make a more informed decision and avoid overpriced or incomplete proposals.

You can request free quotes from local certified contractors to make the process easier.

Staying Comfortable — Putting These AC Buying Tips Into Practice

Now that you know the most common mistakes to avoid when replacing your air conditioner, you’re in a strong position to choose a system that keeps your home comfortable, efficient, and cost-effective for years to come.

Doing a bit of research, comparing quotes, checking rebate options, and choosing a reputable installer are all key steps that help protect your investment.

If you’d like more guidance on choosing the right AC for your home, ACPrices.ca offers resources, comparison tools, and contractor directories to help you make informed decisions.

Need help choosing the right air conditioner?

Visit acprices.ca for expert-backed guides or to request free quotes from certified local HVAC professionals.

📌 When Are You Planning to Install a New AC?

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🤔 Still comparing options or exploring pricing?

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📍 Canadian Cities We Commonly Serve

We help homeowners across Ontario and Canada review cooling options, compare installation costs, and connect with dependable HVAC companies.

Frequently supported service areas include:

Our network of certified contractors covers most major Canadian regions, offering support whether you’re replacing an older system or evaluating new AC models.

👉 See the full list of service regions

🏆 Trusted By Recognized Canadian HVAC Associations

The contractors we feature often belong to respected national and provincial organizations, such as:

These memberships reflect ongoing training, safety standards, and high-quality installation practices.

💰 Key Factors That Influence AC Installation Pricing

Air conditioning costs can vary widely depending on your home and local market conditions. Some of the biggest contributors include:

Cooling capacity required – Larger homes need higher-output units
Installation requirements – Electrical upgrades, duct adjustments, or line-set changes can add cost
Your location – Labour rates and demand vary across provinces and cities
Repair vs. full replacement – Replacing the entire system is typically more expensive than repairing components

Understanding these variables helps you budget accurately for your project.