Yes–they do. But there’s a catch. If you’re relying on one of the newer all-in-one systems to handle the hottest days in southern Alberta, it’s worth looking at a few specifics. Not all models perform the same when temperatures creep past 30°C, especially in homes with poor insulation or large west-facing windows. It’s not that they stop working–it’s more about how well they keep things consistently comfortable during extended warm spells.
The average daily high in July sits around 24°C, but we’ve seen spikes hit the low 30s more frequently over the last decade. And during those heatwaves, older systems–or units sized strictly for winter use–can struggle to maintain that 21–23°C indoor sweet spot. So, no, you can’t just grab the first dual-function unit off the shelf and expect year-round comfort. A technician once told me he saw one undersized system running almost nonstop through a heatwave, barely holding 25°C inside. It was installed in spring… by someone in a rush.
That doesn’t mean the tech isn’t up to the job. It just means there’s more to think about than brand or rating. For instance, variable-speed compressors tend to handle rapid temperature shifts better than single-stage models. Ductwork matters, too. Even small leaks or poorly placed vents can mess with airflow, especially in two-storey houses. Some owners don’t notice this until July rolls around and the upstairs feels like an attic.
If cooling is your priority, ask for a system designed with summer performance in mind–not just one that happens to provide some airflow when it’s hot. And don’t assume that newer means better for every situation. Sometimes, pairing the system with a small backup unit or even a ceiling fan in problem areas makes all the difference. No one wants to find that out mid-July, with a technician booked out for two weeks.
How Modern Heat Pumps Handle Calgary’s Summer Temperature Extremes
If your system is built with a variable-speed compressor, you’re already ahead. These units don’t blast air at full force all the time–they adjust gradually, which helps manage temperature swings better than traditional single-stage models. That matters when daytime highs jump from 22°C to 31°C in under 48 hours. Fixed-speed models struggle with that kind of range. They cycle on and off too often, which can lead to uneven temperatures and short bursts of airflow that never quite keep up.
Go with two-stage or modulating systems, especially in two-storey buildings. A neighbour of mine in Mahogany had a single-stage unit and noticed the upper floor stayed around 26°C while the main level hovered at 22°C. The equipment was technically working, but not well-matched to the layout or weather patterns here. After switching to a dual-stage unit with a bit of zone control, the upstairs finally felt livable–no need for window units or extra fans anymore.
Don’t ignore system placement and airflow
It’s tempting to focus only on the tech specs, but outdoor placement can make a measurable difference. Units crammed into narrow side yards or placed directly under constant sun perform differently than those with a bit of airflow and shade. Direct exposure can bump operating pressures up just enough to reduce cooling capacity during peak hours. That might sound minor, but in small bungalows or tight row houses, you’ll feel it fast.
Noise and runtime might increase–but it’s not always a problem
Modern units often run longer cycles on hot days, but that’s not necessarily a flaw. In fact, longer, lower-intensity runs usually mean better temperature control and less humidity. Some users mistake this for underperformance because the system’s quieter or seems “always on.” It’s not struggling–it’s pacing itself. Ironically, the units that click on and off constantly are the ones burning more energy and giving less consistent results.
What Homeowners Should Know About Sizing a Heat Pump for Cooling
Don’t let anyone guess. Always start with a proper load calculation. Not a quick rule-of-thumb estimate–an actual Manual J or equivalent assessment that takes into account square footage, window orientation, insulation levels, and air leakage. Oversized units short-cycle. Undersized ones won’t keep up when the temperature climbs past 29°C. Either way, you’re not getting what you paid for.
Size isn’t just about square footage. A 1,600 sq ft bungalow from the 60s with single-pane windows and minimal attic insulation may need a higher capacity system than a newer 2,000 sq ft infill with triple glazing and spray-foam. The idea that bigger is safer? That’s the fastest way to create humidity problems. One client I talked to near Bridgeland had condensation forming on vents in July because their oversized system was running for only 5–6 minutes at a time. Indoor air stayed clammy, not comfortable.
Don’t ignore shoulder seasons
You want a unit that performs well when it’s 30°C out–but what about 18°C? Calgary has a long shoulder season, with mild daytime highs and chilly nights. A system sized purely for extremes might struggle to modulate output on those in-between days. That’s where variable-speed technology makes more sense than raw capacity. Smaller units running longer will typically control both temperature and moisture better than larger ones constantly cycling.
Ask about dual-load sizing
Most installers size for winter demand, since that’s where the system has to carry the heaviest load. But that can mean too much capacity during hotter months. Ask if your system can scale performance up or down as needed–some setups use hybrid controls or pair with backup systems to avoid this mismatch. Not everyone needs that level of customization, but if your layout is uneven or you’ve got big south-facing windows, it’s worth the extra planning. Otherwise, you’ll probably end up with fans in the bedrooms again by August.
Comparing Heat Pump Cooling to Traditional AC Systems in Calgary Homes
If your only concern is peak-day performance, a standard air conditioner still delivers stronger output per dollar–at least upfront. These systems are built for one job, and they do it well: drop the indoor temperature fast and keep it there during the hottest hours. In older houses with less insulation or west-facing exposures, that raw output can be more forgiving. They’re also easier to repair in some cases, since the tech hasn’t changed much in decades. Less to go wrong, some might say.
But dual-purpose units carry different benefits. They aren’t always the stronger option in raw capacity, but they offer more flexibility. They stay active longer at lower intensity, which helps manage humidity better. That alone can make a 24°C indoor temperature feel noticeably more comfortable. I had a client in Seton who swapped out a traditional unit for one of these newer systems–not because it got colder faster, but because it felt better during those stretches when the air outside felt thick and stale.
Power use is another angle. Standalone ACs tend to spike on startup and stay at full draw the whole cycle. Newer variable-output units avoid that. Over a full summer, the difference on your bill may be small or significant–it depends how often you’re running it. If you’re only cooling for a few weeks a year, you may not notice much. But if you’re running it from June through early September, the long-cycle performance starts to matter more than expected.
One thing that catches people off guard is airflow. Older AC systems sometimes pair with ductwork that doesn’t distribute air evenly. That can make rooms at the far end of a run consistently warmer. Dual-function systems often come with upgraded fan control, which can help–but only if the ductwork isn’t undersized or leaking. That’s something to check before making the switch. Otherwise, you’re improving one piece of the puzzle and leaving the rest untouched.
Contact “Calgary Air Heating and Cooling Ltd” For More Information:
Address
95 Beaconsfield Rise NW, Calgary, AB T3K 1X3
Phone
+1 403 720-0003
Hours of operation
Open 24 hours 7 days a week