Comprehensive Winterization Guide for Commercial HVAC & Hydronic Systems

Why Winterization Matters for Commercial and Industrial Facilities in Kentucky and Southern Indiana

Winterization is essential for more than just preventing frozen pipes. It is crucial for maintaining operational continuity, avoiding costly emergency repairs, and maximizing energy efficiency during the demanding winter months. Here are some key drivers of winterization:

• Freeze protection for coils, piping, and equipment.

• Energy cost control through insulation and system optimization.

• Occupant comfort and safety in varying load conditions.

• Asset longevity by reducing thermal stress and corrosion.

  
  

Winterization Timeline & Pacing Plan

Month	Primary Focus	Key Actions
August	Planning & Procurement	Review past winter issues, order filters, belts, glycol, insulation, and schedule contractors.
September	Pre-Season Inspections	Inspect AHUs, boilers, ductwork, and piping. Begin insulation repairs.
October	System Optimization	Calibrate thermostats, test heating performance, drain unused water lines, verify glycol levels.
November	Freeze Protection	Finalize insulation, test freeze stats, confirm snow/ice management readiness.
December	Operational Monitoring	Conduct mid-season checks, adjust controls for holiday schedules, monitor for ice buildup.
January–February	Peak Winter Maintenance	Weekly coil temperature checks, verify boiler efficiency, inspect snow-melt systems.
March	Transition Planning	Begin de-winterization planning for cooling season.

1. Air Handling Units (AHUs)

Purpose: AHUs are the lungs of the building. If they are not prepared for winter, you risk frozen coils, poor indoor air quality (IAQ), and uneven heating.

Expanded Tasks:

• Coil Cleaning & Inspection:

- Use a non-acidic coil cleaner to remove dust, scale, and biological growth.

- Inspect for fin damage and straighten bent fins to maintain airflow.

- Check for leaks in hot water or steam coils. Even a pinhole can lead to freeze rupture.

• Freeze Protection Controls:

- Test low-temperature cutouts by simulating a drop in coil temperature.

- Verify that the control shuts down fans and closes outside air dampers promptly.

• Damper Sealing:

- Inspect damper blades and seals for gaps.

- Lubricate linkages and actuators; replace worn seals to prevent infiltration.

• Fan & Motor Maintenance:

- Check belt tension and alignment; replace frayed belts.

- Lubricate bearings per manufacturer specifications.

- Record motor amperage and compare it to the nameplate. High draw may indicate bearing wear or airflow restriction.

• Filter Program:

- Install clean filters before the heating season.

- Consider upgrading to higher MERV ratings if IAQ is a concern, but verify static pressure impact.

2. Boilers & Hydronic Heating Systems

Purpose: Boilers are the heart of hydronic heating. Winterization ensures they deliver reliable, efficient heat without safety risks.

Expanded Tasks:

• Combustion Analysis:

- Use a calibrated analyzer to measure O₂, CO₂, CO, and flue temperature.

- Adjust burners for optimal efficiency and minimal emissions.

• Safety Device Testing:

- Manually trip low-water cutoffs to verify shutdown.

- Test pressure relief valves for proper operation.

- Inspect flame safeguard controls for response time.

• Water Chemistry:

- Test pH (typically 8.5–10 for steel systems) and inhibitor levels.

- Flush sediment from low points to prevent scaling.

• Glycol Systems:

- Test freeze point with a refractometer.

- Top up with a manufacturer-approved propylene glycol blend.

- Check for leaks. Glycol is slippery and can damage flooring.

• Insulation:

- Wrap exposed valves, strainers, and flanges in unheated areas.

3. Chillers (Idle or Year-Round)

Purpose: Even if chillers aren’t used in winter, stagnant water can freeze and rupture tubes.

Expanded Tasks:

• Drainage:

- Drain condenser and evaporator water circuits.

- Use compressed air to blow out residual water.

• Glycol Fill:

- For systems that must remain charged, fill with glycol solution to the appropriate freeze point.

• Electrical:

- Shut down and lock out idle chillers.

- For year-round process chillers, verify crankcase heaters are operational.

4. Cooling Towers

Purpose: Cooling towers are highly vulnerable to freeze damage in idle basins and piping.

Expanded Tasks:

• Drain & Clean:

- Drain all basins, piping, and pumps.

- Remove scale and biological growth from fill media.

• Winter Operation:

- If required, install basin heaters and maintain minimum flow.

- Use wind screens to reduce ice formation on louvers.

5. Ductwork & Insulation

Purpose: Leaky or poorly insulated ducts waste heat and can cause condensation issues.

Expanded Tasks:

• Leak Detection:

- Use smoke pencils or infrared thermography to locate leaks.

- Seal with mastic or UL-181 foil tape.

• Insulation:

- Replace damaged or wet insulation.

- Upgrade R-values in unconditioned spaces to meet ASHRAE 90.1.

6. Thermostats & Controls

Purpose: Accurate controls prevent overheating, underheating, and freeze events.

Expanded Tasks:

• Calibration:

- Compare readings to a calibrated thermometer.

- Adjust or replace as needed.

• Scheduling:

- Program for reduced occupancy periods.

- Coordinate with Building Automation Systems (BAS) for holiday schedules.

• Freeze Alarms:

- Test alarm setpoints and verify notification paths.

7. Hydronic Piping

Purpose: Frozen pipes can burst, causing catastrophic water damage.

Expanded Tasks:

• Drain Unused Lines:

- Use compressed air to remove residual water.

- Tag drained lines to prevent accidental filling.

• Heat Tracing:

- Inspect electric heat trace cables for damage.

- Test thermostats and continuity.

• Expansion Tanks:

- Check pre-charge pressure against system design.

- Inspect for bladder leaks.

8. Pumps & Valves

Purpose: Reliable circulation is critical for freeze protection and heating performance.

Expanded Tasks:

• Seal & Bearing Inspection:

- Look for leaks at mechanical seals.

- Listen for bearing noise.

• Lubrication:

- Follow OEM schedules. Over-lubrication can damage seals.

• Valve Exercise:

- Fully open and close to prevent sticking.

- Lubricate stems where applicable.

9. Building Envelope

Purpose: A tight envelope reduces heating load and prevents cold infiltration.

Expanded Tasks:

• Roof:

- Repair flashing and seal penetrations.

- Inspect for ponding water.

• Gutters & Downspouts:

- Clear debris to prevent ice dams.

- Verify slope for drainage.

• Weatherstripping:

- Replace worn seals on doors and windows.

10. Snow & Ice Management

Purpose: Safety and access are as important as mechanical readiness.

Expanded Tasks:

• Snow-Melt Systems:

- Test hydronic/electric systems before the first snow.

- Verify sensors and controls.

• Deicing Supplies:

- Stock calcium magnesium acetate or eco-friendly alternatives.

• Contractor Readiness:

- Confirm snow removal agreements and response times.

References

Lee Company. (2024, November 13). Winterization checklist for commercial facilities. Retrieved from https://www.leecompany.com/resources/winterization-checklist-for-commercial-facilities/

Powerhouse. (2024). Facilities maintenance winterization strategies white paper. Retrieved from https://www.powerhousenow.com/wp-content/uploads/2024/11/Facilities-Maintenance-Winterization-Strategies-White-Paper.pdf

Furnace Heaters. (2024). Preparing your commercial HVAC system for winter: Your complete guide. Retrieved from https://furnaceheaters.com/preparing-your-commercial-hvac-system-for-winter-your-guide/