The moment a Québec heatwave arrives, the first instinct is to crank the air conditioner to its coldest setting. While the immediate relief is welcome, it often comes with a shockingly high energy bill. This leaves many homeowners asking the critical question: what is the best temperature for AC that keeps my home comfortable without wasting money?
The answer isn’t a single magic number but a smart strategy. Finding the ideal temperature for air conditioning involves balancing personal comfort, energy efficiency, and even the time of day. For Canadian homes, especially during humid summers, setting your thermostat correctly is the key to an affordable and pleasant season.
This guide will provide the recommended AC temperature settings for various situations, explain how to achieve the best AC temperature for sleeping, and offer expert tips to help you save money while staying cool.
The Official Recommendation: The Most Energy-Efficient AC Temperature
According to experts like Natural Resources Canada, the sweet spot for energy conservation during the summer is 25°C (78°F) when you are home.
While this might sound warm to some, it’s a crucial baseline for finding the most comfortable AC temperature for your budget. Every degree you lower your thermostat below this point can increase your cooling costs by 3-5%.
Setting your AC to a frigid 21°C (70°F) might feel nice, but it could nearly double your energy consumption compared to a more moderate setting. The goal is to find the highest temperature at which you still feel comfortable, as this will always be the AC temperature to save money.
A Strategic Approach: Different Temperatures for Different Times
Your house doesn’t need to be kept at one single temperature all day long. A programmable or smart thermostat is your best ally in implementing an energy-saving schedule. Here’s a breakdown of the ideal settings for common scenarios.
| Situation | Recommended Temperature | Why This Setting Works |
| When You Are Home & Awake | 24°C to 25°C (75°F to 78°F) | This range provides a comfortable living environment while representing a significant energy saving AC setting for Canada. It prevents the AC from running constantly. |
| When You Are Sleeping | 23°C to 24°C (73°F to 75°F) | A slightly cooler environment can improve sleep quality. The body’s temperature naturally drops during sleep, and a cooler room supports this process. This is often cited as the best AC temperature for sleeping. |
| When You Are Away from Home | 27°C to 28°C (80°F to 82°F) | Setting the temperature higher when no one is home is the most effective way to achieve a lower hydro bill. It avoids the intense energy use required to cool down a very hot house. |
The Québec & Canadian Context: Why Humidity is a Key Factor
In places like Québec, summer isn’t just hot; it’s often humid. High humidity can make the air feel much warmer than the actual temperature. This is where a modern Daikin air conditioner excels.
Your AC doesn’t just cool the air; it also removes moisture (dehumidifies). It achieves this as warm, moist air passes over the cold evaporator coil inside your system. The water vapor condenses into liquid and is drained away. An appropriately sized system will run in long, steady cycles, effectively managing both temperature and humidity.
This is why an oversized unit is inefficient—it cools the air too quickly (a “short cycle”), satisfying the thermostat before it has had enough time to remove moisture from the air. This leaves you with a room that feels cool but clammy. Effective dehumidification is the secret to feeling comfortable at a higher, more energy-efficient temperature for your AC, even during a sticky Québec heatwave.
Should You Turn Your AC Off Completely When You Leave?
This is a common question, and the answer for most modern systems is no. While turning the AC off seems like it would save the most money, it can be counterproductive.
When you turn the system off, your home absorbs heat all day. When you return, the AC has to run for hours at maximum power to remove all that accumulated heat and humidity, causing a massive spike in energy consumption.
Leaving the AC on at a higher “away” temperature, like 27°C to 28°C, uses a small amount of energy to maintain that baseline. The system works far less hard to bring the temperature back down to a comfortable level when you get home. For any absence of less than a full day, setting it higher is more efficient than turning it off.
Beyond the Thermostat: More Tips for an Energy-Efficient Summer
Your thermostat setting is the biggest factor, but other small adjustments can make a huge difference:
- Use Ceiling Fans: A fan can make a room feel several degrees cooler, allowing you to raise the thermostat setting without sacrificing comfort. Remember, fans cool people, not rooms, so turn them off when you leave.
- Close Blinds and Curtains: Up to 30% of unwanted heat comes from windows. Using light-colored blinds and blackout curtains can significantly reduce solar heat gain.
- Reduce Indoor Heat Generation: Appliances like ovens, dryers, and even computers generate heat. Try to use heat-producing appliances during cooler parts of the day, like the early morning or evening.
- Seal Air Leaks: Ensure windows and doors are properly sealed with weatherstripping to keep the cool air in and the hot air out.
- Perform Regular Maintenance: A clean filter and a well-maintained AC unit run more efficiently. Schedule an annual tune-up with a certified professional to ensure coils are clean and the system is operating at peak performance.
Frequently Asked Questions (FAQ)
What is the best AC temperature for sleeping?
Most sleep experts and energy advisors agree that a temperature between 23°C to 24°C (73°F to 75°F) is ideal for sleeping. It’s cool enough to promote restful sleep without being so cold that it wastes a significant amount of energy overnight.
What is the most energy-efficient temperature for air conditioning?
The most energy-efficient temperature is the highest temperature you can comfortably tolerate. The standard recommendation is 25°C (78°F) when you are home and awake.
What temperature should I leave my AC on while away?
When you are away from home for several hours, set your thermostat to 27°C or 28°C (80-82°F). This significantly reduces energy use but prevents the home from becoming excessively hot, allowing it to cool down relatively quickly upon your return.
Should I change the AC temperature at night?
Yes. Lowering the temperature by a degree or two at night can improve sleep quality. Using a programmable thermostat to automatically lower it before bed and raise it before you wake up is an excellent, energy-saving strategy.
Is 72 degrees a good temperature for AC?
72°F (which is about 22°C) is a very comfortable temperature for many people, but it is not considered energy-efficient. Running your AC at this level will lead to noticeably higher energy bills compared to a setting of 24-25°C. It’s a choice of premium comfort over cost savings.
Conclusion: Smart Settings for a Cool Summer
Ultimately, the best temperature for your AC is a personalized balance. By starting with the recommended ideal AC temperature for Canadian homes (25°C) and creating a schedule for sleeping and when you’re away, you can enjoy a comfortable summer without the shock of a high energy bill. A modern, efficient Daikin system paired with a smart thermostat strategy is the ultimate combination for conquering a Québec summer.
If you want to maximize your home’s efficiency and comfort, contact the experts at Daikin Quebec to discuss the latest in smart climate control technology.
