How West Michigan Winters Impact Your Rooftop Units (And What To Do Before the First Deep Freeze)
West Michigan winters are no joke. Between heavy lake-effect snow, subzero wind chills, and rapid freeze–thaw cycles, commercial rooftop HVAC units face some of the harshest operating conditions in the Midwest. For facility managers and building owners, preparing RTUs before winter isn’t optional—it’s essential for preventing breakdowns, avoiding emergency service calls, and maintaining comfort inside your building.
This guide explains how winter affects your rooftop units, the most common problems we see each year, and what steps you should take before the first deep freeze.
Why West Michigan Winters Are Hard on Rooftop Units
Rooftop units (RTUs) are built for outdoor environments, but West Michigan pushes them to their limits. Unlike equipment protected inside mechanical rooms, RTUs sit directly in the path of:
- Heavy snow and drifting snow
- Ice accumulation and freeze–thaw cycles
- High winds off Lake Michigan
- Extreme temperature swings
This constant exposure makes winter one of the most demanding seasons for HVAC systems. Without proper preparation, building managers may experience:
- Comfort complaints as temperatures fluctuate
- Reduced efficiency and higher energy bills
- Unexpected shutdowns during peak heating demand
- Costly emergency repairs
A small issue in September becomes a major problem during the first deep freeze. That’s why winter preparation is critical for every commercial building with RTUs.
Common Winter Problems We See with Rooftop Units
Ice and Snow Buildup Around the Unit
Snow doesn’t just fall—it drifts. As wind pushes snow across rooftops, it often piles directly against HVAC equipment. This can:
- Block intakes and exhaust openings
- Restrict airflow across heating and cooling coils
- Freeze access panels shut
- Create ice dams that place stress on components
Melt–freeze cycles make the problem worse. Water that melts during the day refreezes at night, forming thick ice around and under the unit.
Coil and Filter Issues in Freezing Temperatures
When coils or filters are already dirty entering winter, the cold amplifies the problem. Restricted airflow can cause:
- Overheating and nuisance shutdowns
- Reduced heating output
- Stress on fans and compressors
- Increased energy consumption
Clogged filters are a leading cause of winter service calls—and one of the easiest issues to prevent.
Electrical and Control Failures
Cold weather is tough on electrical components:
- Moisture can enter electrical compartments and freeze
- Low ambient temperatures affect sensors and safeties
- Control boards can fault or behave erratically
These are the issues most likely to trigger emergency calls during the coldest days of the year.
Economizers and Dampers Sticking or Failing
Economizers rely on moving parts that don’t always behave well in freezing conditions. Common winter issues include:
- Outside air dampers freezing shut
- Dampers sticking partially open
- Sensors failing, causing incorrect airflow
- Wasted energy due to improper mixing of outdoor air
What to Do Before the First Deep Freeze
1. Schedule a Winter-Focused Rooftop Unit Inspection
A proper winter inspection should include:
- Electrical compartment inspection
- Gas train testing (if applicable)
- Belt and bearing checks
- Coil and heat exchanger cleaning
- Filter replacement
- Verification of all safeties, sensors, and control settings
This is the single most important step to prevent winter breakdowns.
2. Clear and Protect the Area Around Each RTU
Snow accumulation around your units is more than an inconvenience—it’s a hazard. Best practices include:
- Ensuring clear, safe access for service technicians
- Removing early-season debris and leaves
- Installing rooftop snow guards or barriers (if drifting is a recurring issue)
- Keeping the area clear reduces airflow blockage and prevents ice buildup
3. Verify Proper Airflow and Combustion Air
Airflow issues are the #1 cause of RTU heating failures. Before winter:
- Inspect and clean indoor and outdoor coils
- Confirm clean filters are installed
- Check flue and intake terminations for blockages
- Ensure combustion air paths are unobstructed
Good airflow ensures stable heating performance when temperatures drop.
4. Confirm Correct Setpoints and Control Strategies
RTUs behave differently in cold weather. Control strategies need to match winter conditions. A technician should verify:
- Occupied vs. unoccupied heating setpoints
- Fan runtime schedules
- Low-ambient controls and freeze protection settings
- Economizer lockouts
- Free cooling disable settings
Correct programming protects comfort and prevents short-cycling or nuisance shutdowns.
Ongoing Winter Best Practices for RTUs
Even with proper preparation, winter requires ongoing attention.
- Perform visual checks after major snow events
- Listen for unusual noises (rattling, grinding, short-cycling)
- Document any odd readings or behavior
- Schedule spring follow-up repair planning
Catching small issues early prevents expensive service calls during extreme cold.
When to Call in a Commercial HVAC Specialist
Contact RMS Pros if you notice:
- Loud or unusual operation
- Repeated nuisance trips or shutdowns
- Frost or ice forming on coils or piping
- Inconsistent indoor heating
- Rising utility bills without a clear cause
A preventative maintenance program is the best defense against winter failures. RMS Pros provides comprehensive rooftop unit inspections, seasonal tune-ups, and proactive service programs designed specifically for West Michigan’s climate.
Protect Your Rooftop Units This Winter
Don’t wait for the first deep freeze. Preparing your RTUs now is the key to reliable heating, lower operating costs, and fewer emergency calls all winter long.
Contact RMS Pros today to schedule your winter rooftop inspection or set up a preventative maintenance plan tailored to your facility.
📞 (616) 350-9175
🌐 https://www.rms-pros.com/preventative-maintenance
