6 Things to Consider When Choosing a New Central AC

How to Choose the Right New Central Air Conditioner Without the Stress

The most important things to consider when choosing a new central air conditioner are proper sizing based on a cooling load calculation (not square footage), energy efficiency (SEER rating), professional installation, sound level, warranty coverage, and ongoing maintenance. Getting the sizing right through a load calculation matters more than any single feature, because an oversized or undersized unit will run inefficiently and struggle to control humidity.

1. What SEER2 rating do I need for a new air conditioner?

SEER2 (Seasonal Energy Efficiency Ratio 2) measures how efficiently a central air conditioner cools your home over a full season. It replaced the older SEER standard in 2023, with stricter testing that better reflects real-world conditions, so SEER2 numbers run about 4 to 5% lower than the old SEER figure for the same equipment. Higher SEER2 means lower energy use. In Canada, new air conditioners must meet a minimum of 14.3 SEER2, while ENERGY STAR certified systems require 16 SEER2 or higher.

2. Why does professional installation matter for a new AC?

Even the best air conditioner will not perform properly without professional installation. Our licensed technicians take the time to assess your home, explain your options clearly, and answer questions about efficiency, warranties, and service plans.

A key part of this process is completing a cooling load calculation. This step ensures the system we recommend is suited to your home, not just based on square footage, but on how your home is built and used.

3. What size AC do I need?

A cooling load calculation measures how much cooling your specific home needs, based on how it is built and used, not just its square footage. When we talk about sizing an air conditioner, we are referring to cooling load. This is the amount of cooling your home actually needs to stay comfortable.

If a system is too large, it may turn on and off frequently, reduce efficiency, and fail to properly control humidity. If it is too small, it may struggle to keep up on hot, humid days. Proper sizing helps your system run smoothly, efficiently, and comfortably.

4. How loud is a central air conditioner?

Air conditioner sound is measured in bels, and most modern central units run between roughly 5 and 7 bels (about 50 to 70 decibels). Lower is quieter. Comfort should be felt, not heard. Air conditioner sound levels are measured in bels, and lower ratings mean quieter operation.

We help homeowners consider sound performance alongside efficiency, especially when outdoor units are located near living spaces or neighbouring homes.

5. What warranty comes with a new central AC?

Most reputable manufacturers offer warranties of up to 10 years, and some provide extended or lifetime coverage on major components like the compressor.

Warranty coverage often depends on professional installation and regular maintenance. We walk you through warranty options so you know exactly what coverage your system includes. When you rent from Reliance, you don’t have to worry about the cost of unexpected repairs or annual maintenance – we’ll take care of that!

6. Are there current Reliance AC offers?

When you are investing in a new central air conditioner, it is always worth checking if any promotions apply. Reliance regularly offers air conditioning promotions that can help reduce upfront costs while still ensuring your system is properly sized, professionally installed, and backed by warranty.

View current Reliance air conditioning offers

Don’t forget about ongoing maintenance

Choosing the right air conditioner is just the first step. Regular maintenance plays an important role in keeping your system running efficiently and reliably.

Most manufacturers recommend annual maintenance to help prevent unexpected repairs, maintain efficiency, and extend the life of your equipment. When you rent with Reliance, ongoing care is included so you can stay comfortable year after year.

In summary

• Energy efficiency ratings help estimate long term operating costs
• Professional installation and correct sizing are essential for performance
• Sound levels and warranties affect everyday comfort and reliability
• Maintenance supports efficiency and system longevity

By understanding these key factors, you can choose a new central air conditioner with confidence. Our team is always here to help you find the right solution for your home.

Want to do more research? Dive into our Ultimate Air Conditioning Guide to find the best home air conditioner. 

Ready to Book a FREE in-home, no-obligation consultation? Click to book online or call us!

*The ENERGY STAR® name and symbol are administered and promoted in Canada by Natural Resources Canada and are registered in Canada by the United States Environmental Protection Agency.