If your tenants are complaining about the heat and your AC is clearly running, you’re dealing with one of the most frustrating HVAC problems in commercial property management.

The answer is almost never ‘your AC isn’t big enough.’ It’s almost always one of a handful of fixable issues; most of them show up clearly in your BAS data if you know where to look.

The Most Common Reasons Your Building Won’t Cool Down

Dirty or Blocked Condenser Coils

After a winter of salt, road dust, and debris accumulation, outdoor condenser coils often go into summer partially blocked. A dirty coil forces your compressor to work harder and raises discharge temperatures, which directly limits how much cooling gets delivered indoors. If you haven’t had a coil cleaning since spring, this is the first thing to check.

Stuck or Failed Economizer

Economizers should cycle based on outdoor conditions. If an economizer damper is stuck open, it’s bringing in hot summer air and forcing your cooling system to overcome it. If it’s stuck closed, you’re losing free cooling and running compressors when you don’t need to. Either way, your building struggles.

Refrigerant Issues

Low refrigerant charge is a common culprit in buildings where equipment hasn’t been properly maintained. A system running low on refrigerant loses capacity. It runs constantly but never catches up with the heat load. This requires a licensed technician to diagnose and correct.

BAS Setpoint Conflicts

In buildings with multiple tenants or zones, BAS configurations sometimes create conflicts. Your heating and cooling are fighting each other, supply air temperatures are set too high for the actual load, or your occupancy schedules don’t reflect how the building is actually used.

A technician reviewing your trend logs can spot these issues in minutes.

Undersized or Degraded Ductwork

Even a well-functioning HVAC system can’t overcome ductwork that leaks conditioned air into ceiling plenums or mechanical rooms. Older buildings across Hamilton and Niagara often have duct systems that were sized for much smaller original occupancy loads, not the much larger current use.

Why Building Automation Makes This Easier to Diagnose

One of the real advantages of an open-protocol BAS like Niagara 4 is that it creates a complete record of how your system has been behaving. Rather than guessing, a technician can pull trend data to see:

• When cooling calls began and how long they lasted
• What supply air temperatures were being achieved
• Whether setpoints were being met in each zone
• Which alarms were active during the hottest periods

Without this data, diagnosing a comfort complaint is a guessing game. With it, the problem usually reveals itself quickly.

What to Do Right Now

1. Schedule a coil cleaning and refrigerant check if it hasn’t been done this season
2. Have a technician inspect your economizer dampers and actuators
3. Pull BAS trend data for the last two weeks and look for zones that aren’t reaching setpoint
4. Check that your BAS schedules reflect current occupancy

Alpine HVAC: Commercial Cooling Diagnostics Across the Golden Horseshoe

Alpine HVAC works with commercial and institutional property managers in Hamilton, Burlington, Niagara, and surrounding areas to diagnose and resolve summer cooling problems. Our technicians are cross-trained in both mechanical systems and BAS so we can trace a comfort complaint from the sensor all the way to the coil.

Reach out to book a free consultation. We’ll find out why your building isn’t cooling and give you a clear plan to fix it.