Keep indoor humidity below 50%–always. That’s the easiest way to discourage uninvited guests with six legs. These insects thrive in damp, warm environments, especially when outdoor temperatures climb. So yes, cooling systems can unintentionally create a more comfortable setting for them, especially if there are leaks or condensation buildup around ducts or vents.
I’ve seen a few apartments downtown where the issue wasn’t the cooling itself–it was how poorly the system was maintained. Cracked seals around windows, moisture near the baseboards, and air handlers dripping into wall cavities. No surprise, then, that small invaders found a way in and stuck around.
In Calgary, where summers have gradually grown warmer, the increased use of indoor cooling brings new challenges. It’s not just about temperature–it’s about airflow, moisture, and how tightly sealed your home is. Units that aren’t regularly serviced can create just enough condensation or leave just enough food particles in return vents to draw attention. And that’s really all it takes.
So, does installing a cooling system increase the risk? Not if it’s done right. A clean, well-sealed, well-drained setup? You’re fine. But skip regular maintenance, let things sweat and drip–and yeah, you might be unintentionally sending out invitations.
How Calgary’s Climate Influences Cockroach Movement Toward Air-Conditioned Spaces
Seal foundation cracks and basement windows as early as May. With overnight lows climbing gradually and early summer heatwaves more frequent than they used to be, insects that typically stay hidden in cooler zones may shift upward through wall voids and piping, searching for steadier temperatures.
These insects are extremely sensitive to fluctuations in humidity–especially during those dry, windy July stretches. If indoor vents or mechanical cooling units create localized moisture or condensation, it can unintentionally attract them to those specific spots. I’ve seen it happen in basement suites with poorly insulated ductwork–one cool vent with just a bit of dampness became a gathering zone. Not a coincidence.
Urban Heat Patterns and Migration Indoors
Residential blocks near concrete-heavy zones, like parking lots or large commercial plazas, tend to retain more heat overnight. Units facing south or west get the worst of it. Insects that linger near dumpsters or alley drains end up tracing that thermal trail toward vents and shaded soffits, especially during dusk. A cooler unit surrounded by warm exterior brick becomes a beacon. That’s when entry points matter most–poorly sealed utility cut-outs or warped window frames are basically invitations.
Timing matters, too. In August, when the temperature outside can swing from 10°C at dawn to nearly 30°C by mid-afternoon, the stress from repeated thermal shocks nudges them inside–not for the chill exactly, but for consistency. Something as subtle as a 5-degree difference inside a wall cavity can shift their activity pattern. And once they find it, they don’t wander far unless forced.
Common Indoor Conditions Created by AC Units That Attract Cockroaches
Seal all moisture-prone areas near your HVAC system–this is the first step. Coolers often generate condensation, especially around ducts, vents, and drain pans. That slight film of water? It’s enough to support small invaders. Leaky refrigerant lines and clogged drainage can quietly create perfect breeding pockets in basements and utility closets.
Temperatures set between 22°C and 26°C, while comfortable for people, also happen to align closely with optimal ranges for insect activity. Add stagnant air from poor circulation in certain corners–behind furniture or under sinks–and you’ve got zones where activity tends to increase. Keeping fans running or using a programmable thermostat with scheduled ventilation might help, though it’s not foolproof.
Dark, Undisturbed Spaces Get Overlooked
Central systems, especially older ones, often have ducting that’s barely insulated and runs through crawl spaces. These areas stay dark and slightly warmer than surrounding rooms, creating easy hideouts. Rarely opened closets, or cabinets near floor vents, can collect debris and crumbs unnoticed–especially in kitchens. Regular cleaning isn’t always enough; sometimes it’s where the airflow doesn’t reach that becomes the problem.
Filters and Dust Build-up Feed the Cycle
Clogged filters don’t just strain the unit–they trap humidity and let airborne particles settle faster. Dust mixed with organic bits from cooking or pet activity? That becomes a food source over time. Some of the newer units manage airflow better, but if you’ve skipped a seasonal service or ignored unusual odours, those small oversights might explain recurring sightings. Change filters monthly during peak usage, and vacuum intake areas thoroughly. Don’t just assume the vents are clean because they look it from the outside.
Preventing Cockroach Infestations Around Air-Conditioned Areas in Calgary Homes
Seal gaps where cool air escapes. Cracks around vents, ducts, and exterior lines–especially near wall penetrations–create entry points. Silicone-based caulking works better than foam in humid zones or where condensation builds up.
Check for moisture regularly. Cooling units often cause minor leaks that go unnoticed. Look behind indoor units, around condensation trays, and along baseboards near the system. Even small drips can attract unwanted guests within a week.
Install mesh screens over exterior vents. A fine 1 mm stainless mesh can block insects without disrupting airflow. Don’t use plastic–it warps in temperature shifts and won’t last a full season.
Don’t ignore debris buildup around outdoor compressors. Leaves, mulch, or pooled rainwater close to the unit create a microclimate that’s ideal for hiding and breeding. Rake back soil, and keep the area dry and exposed to light whenever possible.
Regularly vacuum around indoor components. Behind furniture, under window units, and along wall-mounted systems–those overlooked spots gather dust, hair, and crumbs that make survival easier for intruders.
Store pet food, dry goods, and recycling away from cooling equipment. The warmth from the back of these units combined with food traces creates a draw, especially overnight.
Lastly, schedule yearly tune-ups–not just for performance. A tech can spot and report early signs of nesting or droppings before the problem spreads. Better to catch it early than to wonder why it smells off near the vent three weeks later.
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