Preparing Your Commercial HVAC Coils for This Weekend’s Hard Freeze

A dangerous hard freeze is forecasted across the region this weekend, and for many facilities, that means one thing: HVAC systems are about to work harder than they have all season. At Re-Coil Solutions, we know from years of experience that sudden temperature drops create the perfect conditions for coil failures—and that’s when our phones start ringing nonstop.

Before the cold sets in, here are a few practical steps to help you protect your commercial HVAC coils, reduce the risk of freeze damage, and keep your buildings running safely and efficiently.

Why Coils Fail During Extreme Cold

Coils are especially vulnerable during freezing events. Most failures can be traced back to:

• Rapid temperature swings that stress metal components

• Water trapped inside tubes, which expands as it freezes

• Improper winterization or open outside-air dampers

• Faulty freeze-stats or sensors that fail to trip in time

Even the smallest oversight—an unmonitored economizer, a dirty filter causing low airflow, or a slow valve—can lead to ice forming inside the coil. Once that happens, expansion pressure can split tubes or rupture headers beyond repair.

Warning Signs to Watch for Before the Freeze

If you notice any of the following over the next 48 hours, act quickly:

• Uneven heating or colder discharge air

• Frost or ice beginning to form on coil surfaces

• Sluggish valves or abnormal temperature readings

• Reduced airflow

• Unusual cracking or popping noises

• A history of freeze damage at this location

• Drainage issues or standing water around the unit

Addressing these early can prevent a costly shutdown later.

Your Pre-Freeze Preparation Checklist

A few simple checks now can save you days—or even weeks—of downtime after the freeze.

1. Inspect and Clear Airflow

• Ensure filters are clean

• Verify blowers and fans are operating at full capacity

• Remove any debris or obstructions around the unit

2. Test All Freeze Protection Devices

• Confirm freeze-stats are set correctly and functioning

• Check that sensors are properly placed and making good contact

• Ensure alarm systems are communicating to your controller or BMS

3. Drain and Winterize Where Appropriate

• Drain coils or systems not in use

• Remove sitting water from U-bends or low points

• Inspect for corrosion or weak spots

4. Check Valves, Controls & Glycol Levels

• Test valves and actuators

• Verify proper flow and circulation

• For glycol systems: ensure concentration is adequate for the coming temps

5. Inspect Dampers, Panels & Insulation

• Make sure outside-air dampers close tightly—leakage can flash-freeze a coil in minutes

• Confirm panel integrity and proper insulation coverage

What to Do During the Freeze

Once temperatures drop, vigilance is key:

• Monitor alarms and temperature trends more frequently

• Perform quick visual checks on rooftop or exterior units

• Watch units with previous freeze events closely

• Any low-temp alarm should be treated as urgent—don’t let it ride

Responding quickly during the freeze can be the difference between a minor issue and a burst coil.

How to Recognize Freeze Damage

If a coil does freeze and rupture, you may see:

• Bulged or split copper tubes

• Leaks at headers or return bends

• Sudden loss of heat

• Ice buildup around the coil or casing

• Water pooling once temperatures rise

At that point, shutting the unit down is the safest first step. Unfortunately, once a coil splits, replacement is the only reliable long-term fix.

Why Replacement Coils Surge After a Hard Freeze

When a major freeze hits, entire regions experience failures simultaneously. OEM lead times often stretch out to weeks—or longer. Re-Coil Solutions manufactures custom, exact-match replacement coils built to your specifications, with rapid turnaround and optional on-site measurement by our experienced technicians.

Whether you manage a hospital, university, manufacturing plant, retail chain, or office complex—getting your system back up quickly can’t wait. That’s where we come in.

We’re Here for You — 24/7

Hard freezes don’t follow business hours, and neither do we.

Re-Coil’s coil technicians are on call around the clock throughout the freeze, ready to measure, fabricate, and deliver replacement coils as quickly as possible. If you run into problems, have concerns, or need emergency service, we’re just a phone call away.

When temperatures drop, we step up.

Stay warm, stay alert, and know that Re-Coil is here to help—day or night.