Tag Archives: hvac

Freeze Protection for HVAC Equipment

Much of the country is currently in the single digit temperatures, and “polar vortex” has been officially added to the list of meteorological buzzwords (right on the heels of the “Asperatus Cloud”… how can the weather man keep up?). So it is no surprise that we’ve been fielding calls from adjusters relating to HVAC equipment freeze and water damage from pipe bursts.

The figure below explains why pipes burst when they freeze. It’s all about how the graph curves back down between 4C and 0C.

Density Graph - Freeze Protection

Put simply, water expands by about 9% as it approaches the freeze point. Water is not timid about its need to expand, it does so with lots of force. This simple fact of physics creates billions of dollars in water damage losses for insurance companies. Unfortunately, the alternative is worse; if water didn’t have this destructive little feature, our lakes, oceans and rivers would freeze from the bottom up, causing a major food chain and climate disruption at best, or the end of life on Earth at worst. So, we accept the pipe bursts, whilst nature has provided the fish with a most accommodating under ice environment during the winter months.

There are numerous scenarios that can cause a loss related to pipes freezing. As with most losses, the fault can lie with the owner, installer, manufacturer or a combination these parties. Some common origins of water freeze damage include:

Defective Installation

The National Building Code (encompassing the Electrical and Mechanical Codes) goes a long way to promote pipe freeze protection in equipment and buildings. These codes are normally adopted by state law, and and contractors must adhere to them. The codes increase in complexity every year, and through lack of training or sometimes through willful efforts to cut costs, installation requirements are missed and the building is consequently not compliant with code. Relating to HVAC equipment and plumbing, the codes specify things like minimum insulation R values, acceptable places in the building to install HVAC and electrical equipment, pipe insulation types, freeze protection features and workmanship standards. Some hydronic HVAC systems are required to have chemical freeze protection such as ethylene or propylene glycol. These agents have the undesired effect of reducing the system performance during normal operation, so their use is a tradeoff. But if omitted, or present in too low of a concentration for the regional weather conditions, the results can be disastrous.

Defective Equipment

Since the dawn of the HVAC industry in the late 1800’s, the systems have grown in complexity every year. The complexity often results from our desire to reduce energy costs since HVAC equipment is responsible for a substantial part of most commercial and residential energy use. With complexity comes the possibility for more failure modes. As an example, designers often employ a feature known as “outdoor reset” on heating systems which saves energy by reducing pump speeds and / or boiler water temperature during periods of unseasonably warm outdoor temperatures. A failure in the outdoor reset circuitry, or even mounting the outdoor reset sensor in an incorrect location such as in direct sunlight can cause the “smart” heating system to think it is warmer outside than it is.  The boiler, thinking it is warm outside, reduces or stops heat transfer into the building, and a pipe ruptures. Freeze stats, rupture , heat trace tape and other equipment can also be used to guard against water damage. Each of these devices can fail, and be applied improperly contributing to a loss.

Operator Error

Improper operation of equipment by owners or facilities managers contributes to many freeze accidents. Proper thermostat setting is among the most basic actions that can prevent loss, and insurance policies often carry a requirement to maintain minimum thermostat settings for this reason. Elimination of cold air leaks in the building shell, and proper protection of HVAC elements and piping located in or near outside walls offers a level of protection. Homeowners and enterprise facility managers alike should consider the use of a cold weather checklist to protect property. It is particularly useful to plan for power loss scenarios. Since loss of utility electric power is not an infrequent event, it is advisable not to rely on the presence of utility power as the sole means of freeze protection. Simple procedural steps in a checklist such as “shut of water main if outage duration exceeds 1 hour and outdoor temperatures less than 20F” can save millions of dollars in damages.

Freeze Protection

If you are an owner, counsel or adjuster in need of expert advice on a freeze claim, we can help. Contact Kleinholz Inc. today for more details.

Forensic Engineering Areas of Expertise

Kleinholz Inc. has an extensive background in Forensic Engineering, having conducted 1,000s of hours of research and testing in several different fields. Our Forensic Engineering areas of expertise include:

  • Electric Shock & Electrocution
  • Ground Fault Interuption (GFCI or RCD)
  • Arc Fault Interuption (AFCI)
  • Fires of electrical origin
  • National Electric Code compliance
  • Electrical Safety
  • Power Quality
  • Grounding
  • Power Distribution Systems & Equipment
  • Wind Power Systems
  • Uninteruptable Power Supplies
  • HVAC Systems
  • Data Center Power & Cooling Systems
  • Data Center High Density Containment Solutions
  • Generators
  • Lighting
  • Network and Data Equipment
  • Lightning Protection
  • Security Systems
  • Power Factor Measurement and Correction
  • Electric and Magnetic Field Measurement
  • Electric Vehicles (EV) and Electric Vehicle Supply Equipment (EVSE)