Extreme Winter Weather
by Katie Pfeifer, The Sandner Group
The extreme cold experienced during the last two winters has challenged many school buildings. Record low temperatures and severe wind chills caused many power outages which led to significant damage. Due to the effects of El Nino, the winter of 2015 is expected to be significantly different from 2013 and 2014. Indeed, many northern states are expected to be warmer and drier than normal, and many southern states are expected to be colder and wetter than normal. For the districts in the southern region, now is the time to plan for severe winter weather. For those in the northern region, a milder season does not eliminate all winter weather hazards. Proper planning and preparation can keep your buildings from experiencing the serious losses that many schools faced during the last two years. Freezing water in boiler and sprinkler piping can result in ruptured pipes and serious flooding losses.
A common cause of damage when frigid temperatures hit is power outages. An emergency plan should be in place to provide standby electrical power in the event of a power outage. If the building is not equipped with an emergency generator, a portable generator may be needed to provide power for electric heaters in areas likely to freeze. Implementing a plan to obtain emergency generators should happen now if the district does not already own them or have a plan to otherwise obtain them in place. If it is not financially practical for the district to purchase standby generators, a pre-arranged agreement with an equipment rental company to provide generators should be in place. A backup means to provide power to boiler circulating pumps is a necessity. An electrician will need to connect the circulation pumps to the generator. Generators should only be used in well ventilated areas and proper operating instructions should be provided, as incorrect usage can lead to electrical shock, and prolonged usage in enclosed spaces can result in a build-up of carbon monoxide.
Significant power outages mean your building may be without heat for an extended period of time. One common loss reported is water damage from frozen/burst pipes. Buildings in northern climates are built with water pipes located on the inside of the building insulation which protects the pipes from subfreezing temperatures. Extreme cold and/or holes in the building that allow a flow of cold air to come into contact with the pipes can lead to freezing and bursting. Southern climates often are more vulnerable to winter cold spells. Pipes are more likely to be located in unprotected areas outside of building insulation. The best way to protect your pipes is to slow or stop the transfer of heat. Cracks and holes in outside walls and foundations near water pipes should be sealed with caulking to keep cold wind away. Boxed-in areas should be exposed to interior heat (an example would be opening some ceiling tiles if your building has a drop ceiling). Faucets should be set to drip a slow stream of water. Doors on cabinets containing plumbing fixtures should be left open to allow warm air in.
There are various ways to safely thaw your pipes if they do freeze. Expose the pipes to the inside heat or use a heat gun (but operate it with caution, because the heat may ignite any wood or paper it touches). If a pipe bursts, use the main shut off valve to turn off the water immediately. The best you can do in that situation is to minimize the damage.
Frozen Sprinkler Lines
Frozen sprinkler systems will cause significant damage to a building. Although this can happen at any time, buildings are particularly vulnerable during an extreme cold spell over the weekend or when the building is vacant for holiday breaks. Dry pipe sprinkler systems are more protected because they are generally installed where temperatures are expected to drop below 40 degrees. Allowing water to collect in improperly pitched pipes, failing to remove accumulated water from low point drains, or failing to drain the system properly after the valve has tripped can cause these systems to burst if allowed to freeze. Proper maintenance of the dry pipe system will ensure that does not happen. To prevent freeze-ups, the building maintenance staff should review precautions with the district’s sprinkler service company.
Frozen Uni-Vent Coils
A common cause of water damage to schools is freezing and bursting uni-vent coils. The air dampers in an HVAC unit expose the coils to cold outside air so it is important to protect them. A freezestat is a safety device that monitors the air temperature passing through a liquid filled coil. When the air temperature drops below a pre-set level, the freezestat will stop the unit fans, close the outside air damper, and open the hot water valve. This device is a relatively inexpensive, one time expenditure that can save your school a substantial amount of time and money.
Extreme cold is hard on all types of vehicles. It is important to be diligent in winterizing district buses to ensure the safety of all passengers, particularly younger children who are more vulnerable to hypothermia and frost bite than older students. Gas tanks on all buses should be kept nearly full when dealing with extreme cold to prevent ice from forming in the tank and fuel lines. Additionally, windshield washer fluid and antifreeze levels should be checked prior to an extreme cold spell to ensure both are full and will not cause problems as drivers complete their routes. Buses should also be equipped with materials that can provide aid in case of a breakdown or accident. Items such as salt, sand, road flares, and blankets can be used to respond to an incident and keep students on the bus warm.
Students and employees alike need to make sure they have appropriate winter weather gear even if anticipated exposure time is limited. Accidents and breakdowns happen more frequently in the winter months, and there is no guarantee that you will be able to keep a vehicle heated after an incident occurs on the road. Schools should send out email notices to parents advising that all students should wear appropriate winter clothes to prevent frost bite and/or hypothermia, which can set in very quickly in sub-zero temperatures. Thick gloves, snow pants, hats, scarves, and winter coats should be worn at all times when outdoors. Snow boots should also be worn as salt becomes less effective in sub-zero temperatures, creating very slick surfaces on sidewalks and stairs.
Removing snow in frigid conditions is fraught with hazards. Wearing appropriate clothing to combat the cold should be just the first step when planning to remove snow from sidewalks and steps at district buildings. Be sure to prep any snow blowers while you are indoors to decrease the amount of time spent outside, and make sure your skin is completely dry before putting on warmer layers. As you are removing snow, you should take care not to over-exert yourself, which can cause back injuries and even heart attacks. Remember, your body is already using a lot of energy just to maintain warmth, so you will want to be certain you do not hurt yourself trying to remove snow too quickly or using poor lifting techniques. Never bend at the waist to lift and remove the snow; instead, bend at the knees and lift with your legs, avoid any unnecessary twisting that can wrench your back, and go inside immediately if you begin to feel excessively tired, weak, or start shivering uncontrollably. Fire hydrants need to be cleared of snow and should be visibly marked to prevent injury or damage to machinery by bumping into it. If the discharge chute on a snow blower becomes blocked with snow or ice while in use, the machine must be shut off prior to clearing the jam to prevent severe injuries to hands and arms.
Proper building preparation for winter weather can minimize the risk of winter weather related loss. Many people were caught off guard by the intensity of the last two winters. Advance preparation will help us all be better prepared when severe winter weather hits again.